Low Coolant level

I am probably beating a dead horse here, but I thought I might ask.

My 02 Impala Base model, 3400 has 105k on it. The Low Coolant Light (LCL) came on last night. I came on, went off about 4 minutes after accelerating onto highway. Then came on again after 4 minutes, then on again and off again approx same 4/5 minute interval. This occurred 3/4 times. Please note the temperature gause had NO major changes in temp and I stayed in cruise (75mph) for 25 minutes after it came on.

The temperature gauge did not show a big temperature change while cruising and other acceleration while driving on the highway. I got home and looked at the resevoir, it looked to be below the cool level, when the engine was hot (just shut off a few minutes prior to my looking). I also noticed the hose that went from the radiator (under the cap) to the resevoir had 2 kinks in it, like it was disturbed at 1 time. I did not open the radiator since it was still most likely under presure (will do that tomorrow when it is light out).

I shudder to think it needs another intake manifold gasket, as it had one put on 2 years ago @ 60k miles. At that time, I had a new thermostat, hoses and complete fush done on it. Then a week later the Low Coolant Light came on and no temperature chage occurred. The same mechanic replaced the temperature sensor and it was off for 2 years. Just because of the on/off of the Low Coolant Light, I am getting nervous. I am going to add more orange dexcool to the system, to the proper level in the resevoir. I will get a better chance to see if the radiotpr is actually low.

Anyone had to replace the intake manifold gasket 2x? I will cry if I have to spend another $900 to fix it again. :uhoh:

Thanks, just venting and upset about this car I love to drive...

-Tom

I am probably beating a dead horse here, but I thought I might ask.

My 02 Impala Base model, 3400 has 105k on it. The Low Coolant Light (LCL) came on last night. I came on, went off about 4 minutes after accelerating onto highway. Then came on again after 4 minutes, then on again and off again approx same 4/5 minute interval. This occurred 3/4 times. Please note the temperature gause had NO major changes in temp and I stayed in cruise (75mph) for 25 minutes after it came on.

The temperature gauge did not show a big temperature change while cruising and other acceleration while driving on the highway. I got home and looked at the resevoir, it looked to be below the cool level, when the engine was hot (just shut off a few minutes prior to my looking). I also noticed the hose that went from the radiator (under the cap) to the resevoir had 2 kinks in it, like it was disturbed at 1 time. I did not open the radiator since it was still most likely under presure (will do that tomorrow when it is light out).

I shudder to think it needs another intake manifold gasket, as it had one put on 2 years ago @ 60k miles. At that time, I had a new thermostat, hoses and complete fush done on it. Then a week later the Low Coolant Light came on and no temperature chage occurred. The same mechanic replaced the temperature sensor and it was off for 2 years. Just because of the on/off of the Low Coolant Light, I am getting nervous. I am going to add more orange dexcool to the system, to the proper level in the resevoir. I will get a better chance to see if the radiotpr is actually low.

Anyone had to replace the intake manifold gasket 2x? I will cry if I have to spend another $900 to fix it again. :uhoh:

Thanks, just venting and upset about this car I love to drive...

-Tom

First thing make sure rad is full of coolant.
Is low coolant sensor in rad or coolant tank?
If in Rad I have had good luck just removing them and cleaning the end of them.

my '02 3.8 has done the same thing and I corrected it by cleaning the sensor probe as well, no prob since..

Sadley, cleaning off the sensors is not going to fix your problem it will only make the light go off and make you feel better about it but there will be nothing to feel better about. I have your exact car and this is how it all starts. This car (along with others of the same year and the 3.8 Impala) all were built with Coolant system gaskets that breakdown in dex-cool coolant. Chevy did not know it at the time but they sure do now. What is happening to your car is that there is a gunk building up in the coolant. This gunk is much due to the breaking down of the gaskets and WILL lead to a leak. My car started out excatly as yours is. At about 115,000 miles my low coolant light came on. I did a web search for my car and low coolant problems and sure enough it happens to ALL of them. This is not a matter of if it happens it is WHEN it will happen. Some don't even make it to 60,000 miles. Chevy fixed the problem in there newer cars but only recalled the 3.8 liter engines for the coolant leak problem for 2001 and 2002. After my light went on I brought it in to have the coolant changed and the mecahnic told me when he hooked up the suction he could tell there was a slow leak (he was also VERY familiar with the gasket problem on this car and that Chevy was to blam for putting in faulty gaskets). My leak was so minor that there was never a spot on the ground under it. I have kept an eye on my coolant until my brother could fix it (hasn't yet) but I wish I would have fixed it sooned becasue just this week my CAT converter went out. Apparently when the coolant leakes into the exhaust system is ruins the interior of the CAT and clogs it up. Now my car has lost power and is doing all kinds of funny stuff (at first we thought the tranny was going). There is actually a lawsuit against Chevy for this problems and them not recalling it. If you get it fixed in a shop it will cost anywhere between $700 and $1200 and if your CAT goes out too that will be another $600. Trust me. This IS what is starting to happen to your car. If you clean the sensor and the light goes off either fix the prblems I mentioned or sell the thing as fast as you can before the seals go and the CAT breaks down. It WILL happen. The gaskets were not built to hold up to dex-cool.

Sadley, cleaning off the sensors is not going to fix your problem it will only make the light go off and make you feel better about it but there will be nothing to feel better about. I have your exact car and this is how it all starts. This car (along with others of the same year and the 3.8 Impala) all were built with Coolant system gaskets that breakdown in dex-cool coolant. Chevy did not know it at the time but they sure do now. What is happening to your car is that there is a gunk building up in the coolant. This gunk is much due to the breaking down of the gaskets and WILL lead to a leak. My car started out excatly as yours is. At about 115,000 miles my low coolant light came on. I did a web search for my car and low coolant problems and sure enough it happens to ALL of them. This is not a matter of if it happens it is WHEN it will happen. Some don't even make it to 60,000 miles. Chevy fixed the problem in there newer cars but only recalled the 3.8 liter engines for the coolant leak problem for 2001 and 2002. After my light went on I brought it in to have the coolant changed and the mecahnic told me when he hooked up the suction he could tell there was a slow leak (he was also VERY familiar with the gasket problem on this car and that Chevy was to blam for putting in faulty gaskets). My leak was so minor that there was never a spot on the ground under it. I have kept an eye on my coolant until my brother could fix it (hasn't yet) but I wish I would have fixed it sooned becasue just this week my CAT converter went out. Apparently when the coolant leakes into the exhaust system is ruins the interior of the CAT and clogs it up. Now my car has lost power and is doing all kinds of funny stuff (at first we thought the tranny was going). There is actually a lawsuit against Chevy for this problems and them not recalling it. If you get it fixed in a shop it will cost anywhere between $700 and $1200 and if your CAT goes out too that will be another $600. Trust me. This IS what is starting to happen to your car. If you clean the sensor and the light goes off either fix the prblems I mentioned or sell the thing as fast as you can before the seals go and the CAT breaks down. It WILL happen. The gaskets were not built to hold up to dex-cool.

The poster said he had a 3.4 engine witch is different than a 3.8.
:grinyes: :grinno: :lol:

And it is not the dex cool that causes the problems.
Go back to late 70"s and early 80"s> they had intake and gasket problems back then before Dex cool was even made.:grinno:
Old green or Dex cool will give problems if you do not keep your cooling system serviced.
People that do have a lot less problems.:grinyes: :lol:

The poster said he had a 3.4 engine witch is different than a 3.8.
:grinyes: :grinno: :lol:

And it is not the dex cool that causes the problems.
Go back to late 70"s and early 80"s> they had intake and gasket problems back then before Dex cool was even made.:grinno:
Old green or Dex cool will give problems if you do not keep your cooling system serviced.
People that do have a lot less problems.:grinyes: :lol:

You missed the part where I said I have this EXACT car. My car is the 3.4 liter engine. It IS the dex-cool that is the problem. They simpley only admited to it in the 3.8 liter engines and recalled those. They put the same gasgets in the 3.4L of this year. It is true that unmaintained, you can have the same problem with either coolant but the 2002 Impala owners manual specicially states that dex-cool last 150,000 miles before you need to change it. I have always maintained my car, coolant included, but dexcool still ruined my gasgets. This is where owners of these cars run into problems and where Chevy is too blame for backing dex-cool in there engine for 150,000 miles. There IS a lawsuit on this issue (I am sure they will not get to much against such a big company). The two companies are playing the blam game. Chevy states it is Dexcools fault and Dexcool blams Chevy for gasgets that would not hold up. Chevy did change gaskets in newer cars because they KNEW they broke down in dex-cool coolant. You need to look up this info more if you do not trust me. I have this car and have been dealing with these issues on it for almost a year now. I know plenty about the gasget flaw on these cars and know many others with it too. Mechanics are also very familiar with it (the ones around here anyway). It is sad because I love my car if is wasn't for this one BIG problem.

I have both the 3.4 and the 3.8. The 3.4 has a weak design gasket that allows a minor leak and can be corrected by installing the improved gasket (I replaced the gasket myself). The 3.8, on the other hand, has an issue with the EGR burning a hole through the palstic intake manifold and can be corrected by installing an improved aftermarket mainfold available at better auto parts stores. Also, not all 3.8s were recalled in the affected years. When I recieved the recall notice my car did not meet the prerequisites and it is an '02 Imp.

My 3.8 with the Low coolant light issue does not have low fluid level. Each time I checked it the radiator was full.
The light would come on and go off all the time. I simply removed it and cleaned it up. Whether or not this fixed the sensor the light does not come on now as it did before.

I have both the 3.4 and the 3.8. The 3.4 has a weak design gasket that allows a minor leak and can be corrected by installing the improved gasket (I replaced the gasket myself). The 3.8, on the other hand, has an issue with the EGR burning a hole through the palstic intake manifold and can be corrected by installing an improved aftermarket mainfold available at better auto parts stores. Also, not all 3.8s were recalled in the affected years. When I recieved the recall notice my car did not meet the prerequisites and it is an '02 Imp.

My 3.8 with the Low coolant light issue does not have low fluid level. Each time I checked it the radiator was full.
The light would come on and go off all the time. I simply removed it and cleaned it up. Whether or not this fixed the sensor the light does not come on now as it did before.

I believe you that not all 3.8 liters were recalled. I am not familiar with the exact engines recalled because mine was not. Regardless though, the 3.4 that I own does not have a simple problem. Mine leakes at at least two different gasgets one is at the intake manifold and the other has leaked into my exhaust from yet another gasget. I have had three seperate mechanics look at it and both state the gaskets are deteriorating and leaking. My coolant was not low when my low coolant light went on either and the mechanic did state that the sensor was most likely covered causing the problem but that the leak also existed. I just don't want to see someone else miss this on this car and end up with even more problems. It is a VERY common problem with it. To replace one gasget may not be to hard and anyone a little mechanically inclided can do it but we are talking about the entire gasget kit to be installed which requires much more then a simple fix.
The mechyanics had also stated that the "gunk" that tends to build up in the coolant of these cars is partly due to the gasket deteriorating. I am basing my opinion here (which we all have a different opinion on this) on much research and people looking at my car. I have yet to get a differant answer but that my gaskets are breaking down.
The big thing with Chevy was that they stated 150,000 coolant and this it is not. I am not a car expert but alot of people who own cars haven't a clue how they even run. When the manual says 150,000 coolant they trust the company. I hope you can understand why I could be upset about this. My car should have held out much longer then it did. I might as well bought a GEO. Though some may have the know how to fix this themsleves (I included) many do not and will have to take it in to have it done for a rediculous amount of money.

You missed the part where I said I have this EXACT car. My car is the 3.4 liter engine. It IS the dex-cool that is the problem. They simpley only admited to it in the 3.8 liter engines and recalled those. They put the same gasgets in the 3.4L of this year. It is true that unmaintained, you can have the same problem with either coolant but the 2002 Impala owners manual specicially states that dex-cool last 150,000 miles before you need to change it. I have always maintained my car, coolant included, but dexcool still ruined my gasgets. This is where owners of these cars run into problems and where Chevy is too blame for backing dex-cool in there engine for 150,000 miles. There IS a lawsuit on this issue (I am sure they will not get to much against such a big company). The two companies are playing the blam game. Chevy states it is Dexcools fault and Dexcool blams Chevy for gasgets that would not hold up. Chevy did change gaskets in newer cars because they KNEW they broke down in dex-cool coolant. You need to look up this info more if you do not trust me. I have this car and have been dealing with these issues on it for almost a year now. I know plenty about the gasget flaw on these cars and know many others with it too. Mechanics are also very familiar with it (the ones around here anyway). It is sad because I love my car if is wasn't for this one BIG problem.

It is not the Dex cool.
The problem is with the gaskets and intake manifolds.
GM only warranty them until the warranty runs out.
They did overdo the 150K or 5 year part.
But Under Ideal conditions it might make 150K.
Just use good common brains and service you coolant ever 3 years or 50K.
Intakes and gaskets leaking is nothing new.
I have saw it on older ones and newer ones.
Nothing new there. And the class action suit is not going to amount to much.
They did get someting out of Ford on bad intakes but another deal altogether.
And even then ford weaseled out on the older ones.
If the intake is leaking and it is out of warranty just bite the bullet and fix it.
I have been around under hoods 45 years.
Same old same 0.:rofl:
MT

It is not the Dex cool.
The problem is with the gaskets and intake manifolds.
GM only warranty them until the warranty runs out.
They did overdo the 150K or 5 year part.
But Under Ideal conditions it might make 150K.
Just use good common brains and service you coolant ever 3 years or 50K.
Intakes and gaskets leaking is nothing new.
I have saw it on older ones and newer ones.
Nothing new there. And the class action suit is not going to amount to much.
They did get someting out of Ford on bad intakes but another deal altogether.
And even then ford weaseled out on the older ones.
If the intake is leaking and it is out of warranty just bite the bullet and fix it.
I have been around under hoods 45 years.
Same old same 0.:rofl:
MT

I totally agree with you. I won't fight you on any of that. My point is not who's fault it is at all. The point is if you own this car you will have this problem - there is a strong pattern in this particular engine. I agree too that intakes and gaskets leaking is nothing new but niether is any repair on any car - same old same old. Chevy still made claim of 150,000 mile coolant and they were wrong (they should not have put it in black and white in the manuel). To many people actually believed them.
The lawsuit is against Chevy because it was faulty gaskets that did not hold up to thier claim. Chevy is the one blaming Dexcool. Chevy pretty much admitted to the problem by simpley changing the gaskets in newer model cars and the problem was gone. Dexcool gets pulled into it because they made claim that thier coolant was 150,000 mile coolant. Grant it, it was not thier fault that Chevy used gaskets that would not hold up for 150,000 (regardless of the coolant used). This is where the whole blame game comes in. I am sure the lawsuit won't go too far either. They are too big a company. Bottom line still is that this car has major Coolant leak problems even on maintained vehicles. There was not much an owner could do to stop it from happening. Regular changes could slow the process. That may be why I got over 100,000 before mine went, but the break down still occurs. Letting the problem go by covering up the symptoms is only temporary and the major problem is still going to be underneath. I only told my story to save some other impala owners the whole guessing game. My story is very "cookie cutter" for this car. I love my Impala - how it drives, fuel economy..... but I have had more problems with this car then any other car I have owned and I have maintained them all well in my book. I hope this entire post has been educational for all Impala owners and opens thier eyes to what the root of thier problem could be. As for "biting the bullet" and fixing it - that is being done. The only reason I had been waiting to fix it was because I was under the impression, as others may have been, that the leak was only in the one gasket and since it was not showing up under the car I thought it would be fine until the winter when I could get it into my brothers garage to work on it with him (the entire gasket set is only $50 and the shop wanted to charge me $700). Anyway, I waited to only find out later that all the gaskets were actually deteriorating and that was what ruined my Cat converter now. Needless to say the car will be in for repair this weekend to replace the gaskets and fit a new CAT on the exhaust. I do thank you for you input.

"all the gaskets" are actually two and they are on the lower intake manifold. Some trouble to get down to them but I'm a shade tree mech and I had no problem replacing them.

Yeh, I don't think it is a problem replacing them but if you don't have a shop it is a bit more work. Estimate I had from others who had done it themselves was about 9-10 hours including replacing fluids (oil and coolant). If you are not mechanically inclided though you are going to really pay for this work. I was quoted $700 others I talked to were charge up to $1200.
Yeh, it is truley only "two" gasgets (sets of gasgets) but if that one goes it takes out your CAT and some owners have not had any coolant leak signs pior to it ruining the CAT.

135K miles at the gasket change and my cat does not seem to have been adversely affected.

Consider yourself lucky.
When mine started having power issues (just over 140,000) I looked up problems with it in this car and sure enough. It made sense too since it was linked to the coolant problem that is already so common with them. It was actually a relief since my initial thought was that the transmition was going (as others had thought, who had the same syptoms with thier Impala) I am sure the CAT won't go on all these cars. Probably will all depend on how the coolant leak comes about.

I am the submitter of this post. After a day at the dealers, I know what is the issue.

- sensor on the radiator corroded and shot
- water pump leaking thru weep hole
- intake manifold gasket (shot again, this will be 2nd time I changed it)
- complete cooling system flush
- complete oil system flush

**Cat Conv changed last year under GM notice, free for me**

*All for $1800. I love spending Christmas money on my car. I guess my wife will not get her Diamond jewerly this year... :nono:

-Tom

thanks for posting up the results of your cars diagnosis and I hope this fixes your car. I only wish more people would come back on here after they have corrected the problem and tell us so all of us can be armed with more information.

I am going to post again after the car is fixed. I will let everyone know what else was found once the car was opened up (hopefully nothing else). Car will be fixed in the next few weeks, so I will post after repaired.

-Tom

Maybe you should try MIDAS cause thats alot $1800.

o well.

I had a low coolant light on my 00 3.4 I got 80k miles at that time and It im convinced there was no kind of leak cause my antifreeze never decreased. So I took it to MIDAS and they told me that this happens all the time..... The mechanic told me because I had non-dexcool coolant(green anti-freeze) it took my coolant level sensor out so they replaced that sensor and flushed the antifreeze out and replaced it with dexcoolant(BTW about a year earlier goodyear done my thermostat and they are the ones who put the green anti-freeze in the system - never going back over there). My car has many problems and I'll have to post my own post. MIDAS were very honest I just told them the symptoms and they told me exactly what the problem was....The dealer on the other hand would of not wanted me to talk to the mechanic and they definetly would of not told me it was a known issue. I hope my gaskets etc dont go out!!!!!!!!

Zoe, when my sensor begin acting up I jsut took it out and cleaned it and it works fine now. maybe they were not that honest....

I agree, the sensors do easily get blocked on these cars because of the gunk build up in the dex-cool coolant. Keep in mind though that a gasket pbroblem could still be present too even if you do not see the coolant going down. Mine never looked like it was going down but when it was hooked up to suction to be changed it proved there was a loss of suction showing a gasket leak at the intact manifold. The leak then latter started in the other gasket and went into my exhaust ruining the CAT. Hopefully this is not the case but just keep it in mind incase you see other clues. These cars are known for thier bad gaskets.

I've got a 2002 3.4l base model (bought brand new) with 86k on it right now. At 60k, I flushed out all the Dex-Cool and replaced it with the green "mixes with anything" stuff (from Wal-Mart). I had heard about the Dex-Cool breaking down (or possibly eating the gaskets), so I got it out of there just to be on the safe side. In October of 2005, at 67k, I got my first "Low Coolant Level" message in the message center. At 78k I had to add some coolant (maybe as much as 1 Qt.). At this point, I ordered a new Coolant Level Sensor in June 2006, but never ended up installing it. Instead, I pulled out the old one and cleaned it and this made the message go away for a while. At 80k, my water pump leaked out the weep hole and I replaced it (don't know if this is related in any way). At 82k, the "Low Coolant" message appeared again. At 85k, it appeared again. All this time, I've been religiously changing my oil every 3k miles because I've been concerned that I might have a leak. Well, now I'm convinced I've got a leak.

I think I can do this repair myself. I'm not a mechanic, but I've done just about everything short of rebuild an engine. Although I've replaced half axles, brakes, various motors, timing belts, radiators, etc., I'm guessing this will be the most challenging repair I've ever done because I've never dissassembled the engine in any way.

Here are my questions:

1.) What is the kit# I should be asking for at the dealer?
2.) Is the UPPER manifold gasket, LOWER manifold gasket, or both that is/are defective?
2.) What exactly will be in the kit? 2 gaskets, 4 gaskets, # bolts, etc??
3.) How do I know I've got the "revised" or "updated" kit and not an old kit that's been lying around the service center?
4.) What special tools do I need? In addition to my standard Craftsman tools, I've got a Craftsman "click-type" torque wrench. Will this be sufficient? I've never actually used it because the scale is always too high for the low-torque uses I've encountered in the past.
5.) I have the Chevy manuals. I always buy the manuals right after I buy the car. Is this procedure OK, or was there a revised procedure released with the kit?
6.) What are the critical steps in this repair? Example: cleaning off the old gasket material, torqueing down the bolts, avoiding mixing up parts on re-install, etc...

Here is the info you need.... http://www.chevytalk.org/threads/showflat.php/Cat/0/Number/795792/an/0/page/0#795792

The only thing I would add is GM recommends using new bolts instead of reusing the old ones. I paid $6 each for the long ones, $5 each for the short ones. They come with thread lock already on them. I suggest labeling all the connections with tape so you have no confusion during reassembly and also label the small guides that come off when screws or bolts are removed. I still have a few "extras" lying around. Most importantly buy the gasket set from GM. I tried to go cheap and bought the set from NAPA. It lasted 5 days. The set comes with the 2 gaskets for the lower intake and the gaskets for the plennum. There should also be a paper with the new torgue settings included. Good luck!

Maybe you should try MIDAS cause thats alot $1800.

o well.

I had a low coolant light on my 00 3.4 I got 80k miles at that time and It im convinced there was no kind of leak cause my antifreeze never decreased. So I took it to MIDAS and they told me that this happens all the time..... The mechanic told me because I had non-dexcool coolant(green anti-freeze) it took my coolant level sensor out so they replaced that sensor and flushed the antifreeze out and replaced it with dexcoolant(BTW about a year earlier goodyear done my thermostat and they are the ones who put the green anti-freeze in the system - never going back over there). My car has many problems and I'll have to post my own post. MIDAS were very honest I just told them the symptoms and they told me exactly what the problem was....The dealer on the other hand would of not wanted me to talk to the mechanic and they definetly would of not told me it was a known issue. I hope my gaskets etc dont go out!!!!!!!!

I wouldn't trust MIDAS with a muffler. They went from a muffler joint to full car care overnight. I'm sure their mechanics know what they are doing. :screwy:

I was able to speak at great length to the dealer mechanic and serivce manager about this and the repair. They showed me how things occured and I was impressed they went out for me. I like this dealer, they are the cheapest, but things are done correctly. I am not a shade tree mechanic, but will do things when I can. My father in law is a retired mechanic and said it is best to let the dealer do this type of work. First it would be guaranteed/warrantied and second, too much to do and different tools might be required. He said it was like this back in the day. Before fuel injection things were easier to install repair. He also said stay away from places like MiDAS, Meineke, Jiffy Lube, Sears and Wal-Mart Autocenters, they really haven't a clue and will screw the vehicle up even more.

-Tom

The car has been repaired, for less than $1800. A local shop did it for $1100. The repairs made:

New Upper & Lower Intake Manifold Gasket
New Valve Cover Gaskets
New Oil Pump Seal
Oil Change
DexCool Coolant Flush
Radiator Sensor
Water Pump

The runs great again.... Shout out to Goodyear for fixing the car "www.vespiatires.com"

:cheers:

I didn't want to start a new thread cause there are so many on this subject. But I've never seen pics of the problem or any detail on the job. Just what has to be done and how much the shops charge to do it. I am in the process of replacing mine right now and thought I would take some pics. You can see in the pic that the gasket around the water jacket is smashed and the sealing surface is leaking. It is like this on both sides. I too have had all the same symptoms as everyone else but I went to change the oil today and there was coolant in the oil. I am going to go ahead and replace the upper plentum too since I've heard they tend to crack. Total parts and manual cost me $200. Total removal time about 2.5hrs. (I've never done one before.) All you need is a hand full of metric sockets, a flat head screw driver, some needle nose pliers and a cheap haynes manual. I will put everything back together tomorrow and report back


http://i2.photobucket.com/albums/y40/89Mudslinger/intakepic1.jpg

2.5 hrs reinstall time. That included new oil, and coolant. I don't feel that Dexcool is the problem here. More of a design flaw on the water ports on the gaskets.

So what is the consensus of the mechanics in this site on the type of coolant to put in your engine? Replace with DexCool or go with the green?

The reason I am asking is because I plan on having my coolant system flushed in the next couple of days as there is a lot of buildup in the overflow tank and some in the neck of the radiator. I got a low coolant level indicator on one of my regular drives the other day but it went off on its own. I bought some dexcool but have not put anything in since the light went off. But reading about the gasket problems etc. etc. Im wondering what I should replace the coolant with.

I bought my 02 Impala with high mileage (109K). I have given it two oil changes so far (117k right now, next one is coming up soon) and have not noticed any coolant in the oil. It was owned by a rental company so I am figuring that it had regular maintenance and possibly already had the gaskets changed (luck be a lady tonight ;) Too bad there isnt a way to have that checked out. The car runs great and it never overheats. Hell the engine still looks brand new. Any advice would be greatly appreciated.

There is nothing wrong with Dexcool, the issues are primarily gasket and design related. I have an '02 Impala w/3.8 and a '99 Grand am w/3.4 and run Dex in both. I've replaced the intake gaskets on the 3.4 at 125K miles. I now have 140K miles and the engine is fine. I have 70K miles on the 3.8 with no engine related issues.

As for doing the gasket change yourself, well, I just took a bunch of hi res pics of the engine compartment and then begin taking it apart. No special tools required just very labor intensive. Anybody mechnically inclined should be able to accomplish this task. Total dollars to replace my upper and lower gaskets was 50$ if you don't include the fact that I changed Spark plugs/wires, Drive belt and hoses while I was at it.

So what is the consensus of the mechanics in this site on the type of coolant to put in your engine? Replace with DexCool or go with the green?

The reason I am asking is because I plan on having my coolant system flushed in the next couple of days as there is a lot of buildup in the overflow tank and some in the neck of the radiator. I got a low coolant level indicator on one of my regular drives the other day but it went off on its own. I bought some dexcool but have not put anything in since the light went off. But reading about the gasket problems etc. etc. Im wondering what I should replace the coolant with.

I bought my 02 Impala with high mileage (109K). I have given it two oil changes so far (117k right now, next one is coming up soon) and have not noticed any coolant in the oil. It was owned by a rental company so I am figuring that it had regular maintenance and possibly already had the gaskets changed (luck be a lady tonight ;) Too bad there isnt a way to have that checked out. The car runs great and it never overheats. Hell the engine still looks brand new. Any advice would be greatly appreciated.


Dexcool or green is both good stuff.
Rule No. 1 is do not mix them.
And keep the coolant serviced.
Either one will get strong and build up a acid content if left in the car to long.
GM Dexcool says Dexcool good for 150K or 7 years.
I would suggest changing ever 3 years or 50K

Dexcool or green is both good stuff.
Rule No. 1 is do not mix them.
And keep the coolant serviced.
Either one will get strong and build up a acid content if left in the car to long.
GM Dexcool says Dexcool good for 150K or 7 years.
I would suggest changing ever 3 years or 50K
Totally agree. I would like to add that there has been some confusion in the past whether or not you can mix Dex Cool and green antifreeze in your cooling system. I, for one have said in the past you can do that, but upon further reading and research over the past year or so, I am changing direction on this recommendation. While it is still possible to mix the two, doing so will seriously decrease the life of the Dex Cool and mixing a non OAT (Organic Acid Technology) based coolant (i.e "the green coolant") with an OAT based coolant such as Dex Cool can cause a potentially harmful corrosive situation in your cooling system, further harming your engine.

Totally agree. I would like to add that there has been some confusion in the past whether or not you can mix Dex Cool and green antifreeze in your cooling system. I, for one have said in the past you can do that, but upon further reading and research over the past year or so, I am changing direction on this recommendation. While it is still possible to mix the two, doing so will seriously decrease the life of the Dex Cool and mixing a non OAT (Organic Acid Technology) based coolant (i.e "the green coolant") with an OAT based coolant such as Dex Cool can cause a potentially harmful corrosive situation in your cooling system, further harming your engine.

10-4 on that.
When they first came out with Dexcool they told us not to get even a drop of it mixed with green and to use separate drain pans and funnels for Dexcool and old green coolant.
Over the years I have some mixed with no affect on it but sometimes the green mixed with the orange Dexcool will make brown mud.
Also Prestone has come out with a long life yellow antifreeze that is supposed to mix with anything.
But I always like to flush all old stuff out before adding new stuff.
MT

Thanks for the info guys. I will go with the Dex-Cool on Monday when I have the system flushed. Going to have Jiffy-Lube do it for me as they are running a special on the pressure flush... 35 bucks including fluid. Now if they are using some crazy off brand fluid, I will be bringing my own of course. When the light came on the other day I bought Prestone Dex-Cool. Prestone has always been the brand of coolant I have chosen and have never had a problem.


A friend of mine with an '02 Impala had his done last week and had the green put in so I will let him know about the problems with mixing the two. Funny thing is that the guy at the shop told him that GM was no longer using Dex-Cool...

Thanks again.

01LSIMPALA I think it is the DEX COOL it becomes caustic. I have been told that you should do PH readings of your coolant and never add tap water. You should get disstilled water ( about 79 cents a gallon) not to be cofussed with spring water. We have had other Chevy's with sort of the same upper lower manifold configs that used the green stuff and never leaked. I just read on another web site that the combination of the left over sand in the cooling passages from sand casting that does not get flushed out and the dexcool causes this , then add tap water too... Anyway I have a 2003 3.4L and the lower intake gasket is leaking up by top right side, firewall, while facing the engine. It looks like it is coming out the side and running down the gasket to the top of the block by where the distrbutor wouldbe , now just i think a cap.Then down on the trans to the greound.So I will be doing the gasket repair I guess soon.

01LSIMPALA is yours a 3.4L , the one bolt for the the manifold that is top of the manifold , back by the the firewall side of the intake manifold, right side, sort of recessed under an intake port, do i need a crowsfoot to get at that bolt ? In the factory manual they tighten the valve rocker arm to xx flbs then they use an electronic device to measure another 30 degree turn, should i just guess on 30 degress ? I was told that the only gasket to use was the FEL PRO 'cause it had a thin sheet of aluminum , or metal in the middle of the gasket. What did you use for sealant on the bottom flanges, the shop manual says RTV , is RTV silicon sealant, i hate that stuff. ...anybody have any ideas on this ,,, thanks oh yeah what size are the manifold bolts.?

i recently noticed a coolant leak in my 2000 impala 3.4 engine. I had my manifold intake gasket replaced 2 years ago. It is not over heating or anything like that. I am wondering if it is the water pump?? i had that replaced before, and then had it replaced again a year later. I am just looking a some advice on what it could possibly be.

gonna need to be a bit more specific as to where said coolant leak is coming from...

blmitch11

When do you notice the leak? do you see a puddle on the ground ? Maybe get on your hands and knees and look under your car in the morning. Facing the car, on the left side , water pump, manifold, hose. Right side , manifold , hose. Also the trans fluid is red. You may want to get a really really bright light and look at the top engine block / manifold area on both sides, especially the right side back up under the throttle body. Look at the manifold gasket from the front to the back. Could also be the radiator, the ect sensor ( not tight enough ) the removable threaded , coolant engine block drain plug, a freeze plug ,,, you have to check.

01LSImpala... how much mechanical experience do you have? Just wanted to know as you said you did the gasket replace yourself.

As stated in my previous posts I had the coolant swapped and ended up going with yellow OAT that Jiffy Lube carries (they didnt have DEX).

Well guess what? The gasket must be leaking now. The other day coming back from a 35 mile drive I got gas and upon walking to my car I noticed a small puddle (2inches dia.). I have never had a puddle under my car and this worried me, knowing the issue with the intake gasket. I moved my car and sure enough it was coolant. I opened the hood and looked the engine over. I found where the fluid is leaking to the ground. It is running down the block in the front and is running down the bracket that holds the starter on. I cant tell if any is going through the starter but I can smell coolant when the engine is warm. There is no coolant in the oil as of yet. And tonight I noticed about a 6 inch diameter puddle after the car ran for about 5 minutes. GRRRRRRR.

Im sure that the gasket is EFF'ED but I am contemplating working on it myself as I dont have the money for an 800 dollar fix. Im not a mechanic but Im not an idiot either. Im going to have an estimate done tomorrow to get an actual price.

So here is the meat of my question. What all has to be taken off the top of the motor to replace the gaskets? A list would help me make the decision to do the work myself.

Thanks richtazz, crazy jim, la1, and 01LSimpala for any suggestions.

Dont you all find it sad that when you talk highly of your car, its only then that it starts to have issues. Oh the irony.

(see previous posts concerning the coolant flush)

Pretty much the whole top of the engine has to come off. When I list it out, it sounds quite daunting, but if you organize your work, it's a DIY'able job.

Here's the list: drain coolant below level of intake, disconnect battery negative post, upper radiator hose, coolant transfer tube, upper motor mounts (to get coolant transfer tube out), air intake tube/mass airflow sensor, ignition module/coil pack assembly, upper engine wiring harness (unplug IAT, IAC, TPS, EGR, ICM, MAF, Alternator, O2 sensor, and main junction near alternator), throttle and cruise cables and bracket, serp belt, alternator and bracket, valve covers, upper plenum (leave t/body and coolant transfer tube attached), lower plenum and push rods. I don't think I missed anything.

you have to remove the rocker arms. the intake and exhaust pushrods are of different length. Do not mix them up , put them back in the exact location ( cylinder). I would drain and dispose of the dexcool and put in fresh. Do not use tap water, use distilled water ( not spring water either) . should be about .79 cents a gallon. I would also use a Fel Pro gasket set. If you have a digital camera , take close up pictures of the engine compartment and as you disassemble or label connectors. I think the power steering pump has to be relocated out of the way. Loosen the bolts through the holes in the pulley for the pump. There is a special bolt tightening sequence for the manifold, i will try and post it , tooo late tonight. I would also change your oil and filter when done.

I knew I missed something LA1, and it was the power steering pump. Technically, you don't have to remove the rockers, just loosen them to get the push ords out. I didn't want to list the whole proceedure, including changing coolant, t-stat, hose clamps, etc..., as surrender was basically asking for a list of what needed to be removed. Don't even attempt this job without a good repair manual. You'll need all the torque specs and such that they contain.

I knew I missed something LA1, and it was the power steering pump. Technically, you don't have to remove the rockers, just loosen them to get the push ords out. I didn't want to list the whole proceedure, including changing coolant, t-stat, hose clamps, etc..., as surrender was basically asking for a list of what needed to be removed. Don't even attempt this job without a good repair manual. You'll need all the torque specs and such that they contain.


Thanks guys. I have decided to do the work myself. After reading your post about the list I bought a haynes manual specific to impalas 00-03 ;) Although I have not been this far down into a motor I feel confident I can do this work. Ive taken a look at the engine and saw where the leak is. Its on the outer edge of the lower intake gasket under the throttle body. I actually saw some fluid come out after the engine was off and cooling.

I have gone over the procedures from the haynes manual and have a couple more questions though. In the manual the fuel rails are removed but didnt someone in here say you could leave them on the lower intake? Is that OK to do? Also I dont have a fuel pressure gauge with bleed off valve needed to relieve pressure from the system via the rear fuel rail. Is there any other way to depressurize the system? Thanks for the help.

Yeah, I have to move the power steering pump so I can apply the rtv on the end(s) under the intake. I saw in the manual that they loosen the rocker arms and turn them to allow clearance for the lower intake. They showed a nice trick for the pushrods, poking them through a small carboard box to keep them in the right order. I think that I will use the sharpie to section it off and number the pistons as well. Im getting the FelPro gaskets tomorrow (84.99 from Advance) along with the thermostat, oil and filter. Ive already got the tape for the wiring harness. (I suffer from OCD so organized is my middle name :P I will take pictures the whole way through and post them when I get some time.

Concerning the fuel rails, just pull the injsctors out of their bosses and lay the entire assembly to the side, no need to disconnect the lines.

If you wish to bleedd the pressure off the fuel system just hold a rag over the schrader valve and depress the center prong, a very small amount of gas will come out.

The power steering pump will have to be loosened and placed to the side to gain access to at least one of the LIM bolts.

heres a pic of mine after I got it all back together
http://i23.photobucket.com/albums/b388/jfp43/IMG_0962.jpg

even easier on the injector rail, if you just loosen the bolts that hold the rail down, it will give you enough lateral flexiblilty to get to all the lower intake bolts without having to remove the injectors. I disconnect the main wiring junction near the alternator, and leave the injector harness with the lower intake.

As far as fuel pressure, if you haven't started tearing it down yet, remove the fuel pump fuse, start the car and let it die, fuel pressure is now relieved.

I don't remember if we discussed this before, but while you have it down, replace the oil pump drive o-ring while you have it down. It's a 2 minute job at that point, versus disassembling the top of the motor again if it starts leaking. Fel-pro part number is 70800 on the seal, and I also put a 70194 paper gasket in there as added insurance.

There is one point I fail to understand after reading thru this long thread... On the 3.8L engine the coolant level sensor is located on the radiator, about 6 inches below the radiator cap... If you truly have a low coolant problem, due to a leaking LIM or UIM gasket, or some other issue, and you have lost enough coolant so that it is below the sensor, then the sensor should trigger and stay triggered ON all the time... If the sensor is slightly gunked up and is false triggering, on and off, then you just have a dirty sensor, not necessarily a leaking gasket... Some gunk buildup in your dex-cool just means that you need to flush out your cooling system... It doesn't always mean your intake manifold gaskets are leaking... Is my logic correct on this?

see posts #37 and #42 Gems, the intake can be seen leaking externally on the driver's side, so it's definitely an intake gasket.

even easier on the injector rail, if you just loosen the bolts that hold the rail down, it will give you enough lateral flexiblilty to get to all the lower intake bolts without having to remove the injectors. I disconnect the main wiring junction near the alternator, and leave the injector harness with the lower intake.

As far as fuel pressure, if you haven't started tearing it down yet, remove the fuel pump fuse, start the car and let it die, fuel pressure is now relieved.

I don't remember if we discussed this before, but while you have it down, replace the oil pump drive o-ring while you have it down. It's a 2 minute job at that point, versus disassembling the top of the motor again if it starts leaking. Fel-pro part number is 70800 on the seal, and I also put a 70194 paper gasket in there as added insurance.

Nope, havent gotten started on the motor yet. I had a meeting this morning and I have to get my daughter from school in 45 minutes. I have to work the next four days so this might have to be done in a tear down on one day and rebuild on the next. So in preperation... more questions!

On the oil pump drive o-ring replace, exactly where will I be looking? Between the heads or to one end or the other of the block? Dont see it in the manual. And does the paper gasket go under or over the rubber o-ring?

Also, the torque settings are 18 ft/lbs for upper manifold bolts and 62 in/lbs (step one) and 115 in/lbs for step two. Well when divided by 12 to get ft/lbs the first step for the lower manifold is 5.2ft/lbs and step two is 9.6 ft/lbs. Does this sound right? Kinda seems a bit low to me. I know that torquing the bolts correctly is paramount in this fix.

I have a ft/lbs torque wrench that starts at 10lbs. Can I back my torque wrench down from 10 to 5.2ft/lbs? I tested that out on a radiator strut bolt and the wrench seemed to work ok... but is that a reliable way to get 5.2ft/lbs or torque? I am just about at my limit of expense for now on this project. Besides, the in/lb torque wrench I looked at today started at 120.

Oh and an important question I hope you can clear up.... In the manual there is no mention of step one or two in the procedure, just on the torque spec. page. Am I correct in assuming that step one involves torquing all the bolts to the first spec and then going through and retorquing to the second spec?

I plan on going into this fix well prepared and really appreciate all your good feedback guys.

jim


PS: I hope your still around tazz. Just saw you online but now you are gone! Definately going to follow your advice on the fuel rails and how to relieve the fuel pressure.

Hey guys, Im in the middle of the tear down and will soon be at the lower intake.

Bumping this one up so I can get some feedback on the torque procedures in the previous post.

Its taking me a while to do, but as I said Ive never done something like this before. Its going ok, just a bit slow. Taking pictures all the way through and will make sure to post them.

Tazz or CrazyJim, help please.

lower intake manifold bolts are 115 lbs/inch torquing them from the middle and working your way outboard. On the upper intake be extremely careful with the front right hand corner as the part that contains the threads is prone to shearing off (don't ask me how I know this).

lower intake manifold bolts are 115 lbs/inch torquing them from the middle and working your way outboard. On the upper intake be extremely careful with the front right hand corner as the part that contains the threads is prone to shearing off (don't ask me how I know this).

Thanks Jim. I will torque the middle to 62in/lbs and then work the outer ones up along with them. The manual says to torque the middles ones down first to prevent the angled ones pulling the manifold out of place.

As suspected the rear bank was leaking out the drivers side water jacket. It was pulling a tiny bit of oil into the coolant but not vice versa thank goodness. The FelPro's look like they would hold up to a tank ;)

I have pictures of everything and will make a post with them. Thanks again to everyone in the forum that helped. You know who you are.