PLENUM Intake Failure, What kind of fluid did you use?

At my mechanics today, we where talking about the PLENUM Failures. A comment was made that the ones that have came in to the shop, all failiers have ben with the green coolant. None so far have ben seen using the GM coolant.
If you had an intake, PLENUM failure, what kind of antifreeze did you have in it?
Thank you,
Chris.

I think your mechanic is misinformed,the failures with the plenum are not from the antifreeze being used,that problem was with the lower intake manifold gaskets,the problem with the plenums was caused by deteriation of the plenum material due to heat of the egr exaust gases (check the facts).

I think your mechanic is misinformed,the failures with the plenum are not from the antifreeze being used,that problem was with the lower intake manifold gaskets,the problem with the plenums was caused by deteriation of the plenum material due to heat of the egr exaust gases (check the facts).


It depends on what year car you are talking about. I have seen intake gaskets leaking, melted plenums as well as plenums that blew apart. All the issues I have seen used Dexcool.

It depends on what year car you are talking about. I have seen intake gaskets leaking, melted plenums as well as plenums that blew apart. All the issues I have seen used Dexcool.


Well its sounds like I read wrong and since you are better informed than I,what year did GM start using Dexcool and in your opinion are the engines better now than they were when all these problems started?and also does GM still use it? Thanks

Dexcool is not the issue with the manifolds, egr passages were poorly designed on the 3800. 1995-2003 roughly. The 3.1 and 3.4 have intake gasket problems that some have blamed Dexcool for, again not true.

Well its sounds like I read wrong and since you are better informed than I,what year did GM start using Dexcool and in your opinion are the engines better now than they were when all these problems started?and also does GM still use it? Thanks

GM started using dexcool in 1995. In my opnion I don't see a difference between Dexcool and the green antifreeze but I do think that the GM engineers have lowered the standards used to build cars. Parts are not made the same and I believe they have a higher failure rate. I also think GM isn't the only company having these issues just ask any Ford tech about the 6.0L.

Also with the internet growing these issues can be found and you can find a large group with the same problems. What if I tell you that the intake melting you speak of only happens with 1% of the 3.8L engines. While I have done my fair share of intake plenums I can say that most of the 3.8L engines will never need this repair. With our site Automotive forums designed to help people with their car problems all you see is owners with problems yet people whose car never breaks you will never see them here.

As far as I know GM will continue using Dexcool until something better comes out.

It depends on what year car you are talking about. I have seen intake gaskets leaking, melted plenums as well as plenums that blew apart. All the issues I have seen used Dexcool.


Flatrater: I have the 2003 Series II. The antifreeze has dropper from the hot line in the plastic tank to about 1/8 inch below the cold mark. This is after about 12000 miles and eighteen months. Should i worry about the gasket leaking. The car has 26000 miles on it.
Thanks, Popeye

GM started using dexcool in 1995. In my opnion I don't see a difference between Dexcool and the green antifreeze but I do think that the GM engineers have lowered the standards used to build cars. Parts are not made the same and I believe they have a higher failure rate. I also think GM isn't the only company having these issues just ask any Ford tech about the 6.0L.

Also with the internet growing these issues can be found and you can find a large group with the same problems. What if I tell you that the intake melting you speak of only happens with 1% of the 3.8L engines. While I have done my fair share of intake plenums I can say that most of the 3.8L engines will never need this repair. With our site Automotive forums designed to help people with their car problems all you see is owners with problems yet people whose car never breaks you will never see them here.

As far as I know GM will continue using Dexcool until something better comes out.


Than'ks for the input and I can't agree with you more,if people would only pressure the mfrs.with the problems they see and have them listen GM would not be in the trouble there in.I didn't know there was an issue with the plenums until I got on this forum,Ive owned 3 Olds and just purchased an 01 Buick and can't complain about the 95's but the 98 was a regency and I can say that the 98 needed more attention than the 95's ever did and thank's to Consumers I'm having a hard time selling it.I hope with the upcoming GM cutbacks your not effected,good luck and thank's again. Frank

Flatrater: I have the 2003 Series II. The antifreeze has dropper from the hot line in the plastic tank to about 1/8 inch below the cold mark. This is after about 12000 miles and eighteen months. Should i worry about the gasket leaking. The car has 26000 miles on it.
Thanks, Popeye

When you check your level is the engine hot or cold? I perfer to check the level on a hot engine. It's isn't abnormal to lose some coolant over time. Best thing to do is keep an eye on the level, if it goes down in a short amount of time like 1000 miles then I would look for a leak. The most common place for your 2003 to leak is the throttle body to plenum area and the plenum to lower intake area. Sometimes the coolant will not puddle so look for a red or orange stain. If you see a puddle or a stain then you have a leak in that area. Replacing the gaskets isn't hard and I'm sure you could do it on your own.

Than'ks for the input and I can't agree with you more,if people would only pressure the mfrs.with the problems they see and have them listen GM would not be in the trouble there in.I didn't know there was an issue with the plenums until I got on this forum,Ive owned 3 Olds and just purchased an 01 Buick and can't complain about the 95's but the 98 was a regency and I can say that the 98 needed more attention than the 95's ever did and thank's to Consumers I'm having a hard time selling it.I hope with the upcoming GM cutbacks your not effected,good luck and thank's again. Frank

I'm sitting here watching the ship sink, the great SS General Motors is taking on water. It has already be predicted that GM will file bankrupcy within 18 months time. GM will be around a long time after this. All GM will do is kill the unions and pensions which will allow it to remain, leaner and cheaper. Also GM will shut the doors to the American factories pushing them overseas, to Mexico and Canada. If you noticed 90% of the cuts are in US plants. Right now Canada builds more GM cars then Detriot does.

All of these cuts will filter down to the dealer level, can't help not to. I have already watched my work load drop the past 3 years. But I do know that we will see GM cars for years to come and if I have to I can jump ship moving on to another line of work if I have to.


BTW with the melted intakes the way I reccomend fixing it is to replace the intake with a good aftermarket part which has a larger diameter opening for the EGR. The GM intake is cheaper but you need to replace the lower intake with GM's repair.

BTW with the melted intakes the way I recommend fixing it is to replace the intake with a good aftermarket part which has a larger diameter opening for the EGR. The GM intake is cheaper but you need to replace the lower intake with GM's repair.

In my town the aftermarket intakes are cheaper (to the same) then the stock ones. I have access to at least three different brands of aftermarket intakes (Two local, one internet). Have you heard anyone that I should stay away from?

A lot of time it's hard for me to decide what thing to get. With different ones it's making it hard for me to figure out what one to get.
One is for $97 and says, "Re-Engineered to Prevent Common Failure Patterns, Reinforced EGR & Coolant Passage Walls for Greater Durability."

I have a mechanic who will do the job for $500-$600. Seems like it's just taking the top off and putting the new one on (I know it's a little more then JUST that). Why is it so expensive just to take the manifold off and replace it? I think I'll try and do it myself.

When I get the money, I'm going to replace it before it goes out. I don't want to have to fix anything else after my engine fills with liquid.

I didn't mean to start an argument about the different coolants. It's just an idea we had when talking. I thought what the heck, I'll post it on the forums. Thank you,
Chris.

BTW with the melted intakes the way I reccomend fixing it is to replace the intake with a good aftermarket part which has a larger diameter opening for the EGR. The GM intake is cheaper but you need to replace the lower intake with GM's repair.[/QUOTE]

Flatrater,

Could you recommend an intake manifold manufacturer? It appears that there are several who claim to be the best in solving the EGR passageway problem. Also, what are your recommendations for the lower intake. Thanks for the advice!

I have a mechanic who will do the job for $500-$600. Seems like it's just taking the top off and putting the new one on (I know it's a little more then JUST that). Why is it so expensive just to take the manifold off and replace it? I think I'll try and do it myself.


If all you are getting done is the upper intake then 500 dollars is too mich. The labor per most labor time guides is less then 2 hours of labor. Your mechanic must be charging over 100 dollars a hour. I do the whole job parts and labor under 400 dollars. 200 dollars for parts and 160 for labor.

The replacement isn't hard, I'm sure you are capable of doing it yourself. Frankly it takes me 45 minutes to replace the plenum, your first time might take 2 hours.

Could you recommend an intake manifold manufacturer? It appears that there are several who claim to be the best in solving the EGR passageway problem. Also, what are your recommendations for the lower intake. Thanks for the advice

The only thing I would want in an aftermarket replacement is a larger EGR hole. An intake that is reinforced sounds like it will still melt but take longer. The key is not to have the plastic touching the EGR tube.

If all you are getting done is the upper intake then 500 dollars is too mich. The labor per most labor time guides is less then 2 hours of labor. Your mechanic must be charging over 100 dollars a hour. I do the whole job parts and labor under 400 dollars. 200 dollars for parts and 160 for labor.

The replacement isn't hard, I'm sure you are capable of doing it yourself. Frankly it takes me 45 minutes to replace the plenum, your first time might take 2 hours.



The only thing I would want in an aftermarket replacement is a larger EGR hole. An intake that is reinforced sounds like it will still melt but take longer. The key is not to have the plastic touching the EGR tube.

Hello

When I bought my 97 the guy I got it from said that the Plenum problem was fixed. Is the plenum something that could be removed and checked and put back on? From looking at the replacements it did look like it had an O-ring as a seal.

I'm not sure to trust the guy I got it from. The oil sensor in the pan was disconected on the oil pan. I'm wondering what else was covered up? This got me thinking if the plenum was really fixed.

Regards

Dan

BTW with the melted intakes the way I recommend fixing it is to replace the intake with a good aftermarket part which has a larger diameter opening for the EGR. The GM intake is cheaper but you need to replace the lower intake with GM's repair.

One thing I don't understand is if the problem is the plastic melting away, why do I have to replace both upper and lower gaskets?

Can I just replace the plenum and gasket without the lower going out?

Two shops told me they wouldn't do the job unless they did BOTH gaskets.

I was told the ones GM now sells are better then what came on the cars originally. They improved them or something like that.

What do you think? A "new" GM or an aftermarket? What brand aftermarkets are good or bad? Thank you,
Chris.

One thing I don't understand is if the problem is the plastic melting away, why do I have to replace both upper and lower gaskets?

Can I just replace the plenum and gasket without the lower going out?

Two shops told me they wouldn't do the job unless they did BOTH gaskets.

I was told the ones GM now sells are better then what came on the cars originally. They improved them or something like that.

What do you think? A "new" GM or an aftermarket? What brand aftermarkets are good or bad? Thank you,
Chris.

GM decided that instead of fixing the size of the hole in the plenum they would reduce the size of the EGR tube. The only difference in the new lower intake is the diameter of the tube, it's smaller. That is why GM states to replace the lower and upper intake.

All dealers that use GM parts are required to change both intakes. Without changing both they cannot warranty the repair.

To me the old and new upper intakes look the same but I was told that GM improved the materail around the EGR tube making it thicker.

When I quote a repair to an out of warranty customer I give both options. The new GM upper and lower or the aftermarket upper. The aftermarket upper doesn't need the lower intake replaced. Price wise the aftermarket is cheaper and most people will go aftermarket.

One thing I don't understand is if the problem is the plastic melting away, why do I have to replace both upper and lower gaskets?

Can I just replace the plenum and gasket without the lower going out?

Two shops told me they wouldn't do the job unless they did BOTH gaskets.

I was told the ones GM now sells are better then what came on the cars originally. They improved them or something like that.

What do you think? A "new" GM or an aftermarket? What brand aftermarkets are good or bad? Thank you,
Chris.

My girlfriend has a '97 that I purchased the Ken-Co kit for last summer but never installed it yet. Look into this. The shops and dealers just want to totally switch out the old system and therefore eliminate a possible problem with the customer. Your looking at big money here. The Ken-Co kit should eliminate the problem. Hers has a slight coolant usage problem, but I'm constantly checking the overflow resivoir and the fluid in the radiator. I'm waiting for it to get slightly worse before I tackle the job. My kit was somewher in the $60 range. Much better than replacing the plenum,gasket,lower intake with new design,and gasket to a cost $1500 or more. Good Luck

Your 1500 or more quote is extreme. The total cost is less than 700.

Your Ken-co kit is that the one were you make the hole bigger and glue in a metal collar into the hole? If that is the one then it is only a bandaid fix since the metal collar transfers heat which will cause the plastic to melt even more. Might as well buy a new GM upper intake for less than 60 dollars because it will last just as long as the glued in metal collar.

bump

Well its sounds like I read wrong and since you are better informed than I,what year did GM start using Dexcool and in your opinion are the engines better now than they were when all these problems started?and also does GM still use it? Thanks

Here is an article about Dex-Cool and GM. I had Dex-Cool in my personal vehicle (2000 LeSabre) and after 50,000 miles I noticed that sludge was starting to form in the coolant recovery tank. I had the cooling system flushed and replaced with the green antifreeze. Some people say that Dex-Cool is better than the original, but when I saw sludge forming, that was enough for me to get it out of there.

http://www.noln.net/features/feature3.html

[QUOTE=stuzman]50,000 miles I noticed that sludge was starting to form in the coolant recovery tank. I had the cooling system flushed and replaced with the green antifreeze. Some people say that Dex-Cool is better than the original, but when I saw sludge forming, QUOTE]

Do you think what you saw was the antileak material from the factory collecting in the recovery tank? I had that on both cars.

[QUOTE=stuzman]50,000 miles I noticed that sludge was starting to form in the coolant recovery tank. I had the cooling system flushed and replaced with the green antifreeze. Some people say that Dex-Cool is better than the original, but when I saw sludge forming, QUOTE]

Do you think what you saw was the antileak material from the factory collecting in the recovery tank? I had that on both cars.

I'm not sure, but it created a ring around the coolant tank which remains to this day. I removed the tank to clean the remaining sludge that was suspended in solution. So, either way, if it's the Dex-Cool or the anti-leak material, it's flushed and I haven't seen it forming since.

Might as well buy a new GM upper intake for less than 60 dollars because it will last just as long as the glued in metal collar.
Is "The new GM Upper Intake" the Plenum? How can I get one for $60?

I want to replace the Plenum, and while I'm at it replace the lower gasket.

I've read where people say only use the GM gaskets. Others say use this brand or that brand, not GM.

GM or Aftermarket Gaskets? Any brand better then others?