Replacing intake gasket...

The Delco part number for the two o-rings needed for the fuel rail inlet and outlet (where the pressure regulator plugs into the fuel rail) is 217-461. Price ranges form $15 to $30 depending on where you shop, and may be a special order item.

It also goes by GM part number 17113034.

I'm about to do the LIM gasket job on a relative's car. Can anyone run down the revised torque specs applicable to the '03 3400 in a Pont. Grand Am. I will get a book for the bolt torquing sequence but I was wanting the latest torque specs for the upper intake, LIM and rocker arms for '03 3400.

Found this forum and what a help!!!! :frown: Of course I had already started and now need help. From everything I've read I'm not in to much trouble yet. I've got the upper plenum removed. Alternater off, power steering off , coil packs off. Was Looking to remove the valve covers next and cannot get to the lower bolt on the passenger side. The bracket that holds the alternater, and the belt tensioner is in the way and I'm trying to remove it. I've removed 3 or 4 bolts with 15mm socket and does anybody know where they are all at???? I removed 1 from the back and 2 or 3 from the front....does one of the head bolts also hold it???

1999 Olds Cutlass 3100
This is the bracket;
http://i55.photobucket.com/albums/g128/lagogarda/PIC-2823.jpg

here's the one in the back I have out.
http://i55.photobucket.com/albums/g128/lagogarda/PIC-2824.jpg


then the two in the front side
http://i55.photobucket.com/albums/g128/lagogarda/PIC-2825.jpg

Found this forum and what a help!!!! :frown: Of course I had already started and now need help. From everything I've read I'm not in to much trouble yet. I've got the upper plenum removed. Alternater off, power steering off , coil packs off. Was Looking to remove the valve covers next and cannot get to the lower bolt on the passenger side. The bracket that holds the alternater, and the belt tensioner is in the way and I'm trying to remove it. I've removed 3 or 4 bolts with 15mm socket and does anybody know where they are all at???? I removed 1 from the back and 2 or 3 from the front....does one of the head bolts also hold it???


I think you have to take tensioner bolt out. I just complete the job on the Pontiac and that was my second car I've done this job on, and both times I unbolted the tensioner. the idler above the tensioner does not have to be unbolted though.

:thumbsup: That was it!!! Thanks.!!
:cheers:

Hi guys... any idea how must this job would cost if is done by a mechanic?

Typical shop cost is probably about $800-$1000, maybe more depending on where you are.

For DIY, the minimum recommended parts needed would be under $75, not counting any routine replacements you decide to do at the same time (e.g., belt, plugs, plug wires, t-stat, etc.).

Hello all. I am finishing up my 1998 lumina 3.1L lower and upper gasket set. I purchased the fel-pro kit at advance auto with all the needed gaskets. Also got new injector orings, fuel line orings, thermostat, upper lower hoses, heater core quick disconnect and so on....

I have enjoyed the project and appreciate the help I got from this site. Our mechanic quoted $1673.00 for the job. He recommended that I junk the car. This is my sons car by the way.The car had other issues like #2 and #4 fuel injector bad. Cam sensor cracked and defective. #3 and #4 spark plug wires open.

So I have invested $330 so far and I am ready to start her up. BUT I found a broken vacuum port on the upper aluminum manifold front drivers side near the pcv.

Now this port is sheared clean off. I was saddened as the excitement of the completion and start up slowly sank like a tropical sunset.:disappoin

Does anyone have a fix for this port that they can share other than get a new upper manifold from the salvage yard. I'm so close but yet so far away.
Thanks
Rick

Getting JY upper manifold might be the longest lasting, quickest, and most reliable fix, and it would keep it stock and would be my first choice. But there are alternatives, such as maybe drill out, thread, and install a nipple where the port was, or maybe try some (well, more likely a lot for strength) high temp epoxy to reattach the broken piece, or variations there-on.

I don't know if you guys have seen this tool or not, but I was a GM tech and it is the difference between making awesome flat rate on intake gaskets, or not, it makes tourqing those pain in the butt corner bolts a breeze. Far as I know it is only from snap on, mine is chrome and 12 point, but same idea. It is 3/8 drive, but the extension and socket are 1/4 drive physical size. It has a ball swivel, so unrestricted movement to a whole lot of degrees.

I don't know how to post the pic, but cut and paste this link to see snap ons picture of a power one (black finish), but same principal as mine.

There is also a tool to compress the rocker arms, it is a lever that fits the arms. If the valve covers aren't leaking, don't take em off, slip this tool in and take the p rods off without taking the valve cover off.
Turns a 5.5 hour intake gasket job into 3 hours or less if you have air tools too

heres the first tool
http://buy1.snapon.com/catalog/item_Lg.asp?picFile=/59400/59356.JPG

heres the second, its the short one, they make one about 10 inches longer, but I see no need for it, they are easy to compress with it, and it has a spot for a ratchet for extra leverage too.
http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=78511&group_ID=1558&store=snapon-store&dir=catalog

I don't know if you guys have seen this tool or not, but I was a GM tech and it is the difference between making awesome flat rate on intake gaskets, or not, it makes tourqing those pain in the butt corner bolts a breeze. Far as I know it is only from snap on, mine is chrome and 12 point, but same idea. It is 3/8 drive, but the extension and socket are 1/4 drive physical size. It has a ball swivel, so unrestricted movement to a whole lot of degrees.

I don't know how to post the pic, but cut and paste this link to see snap ons picture of a power one (black finish), but same principal as mine.

I don't think I've seen that tool before on here. Those corner bolts are a pain getting to even with a 3/8" drive crow's foot, especially on the later models that seems to have bigger manifold runners. I thought what was needed was a 1/4"drive to make room. Some bolt kits give you a 13mm head for the end bolts and give you a little more room to swing the crow's foot, but this seems like a better solution. I wonder if they have it in 13mm too? Maybe it'd help with the pesky power steering bolts?


There is also a tool to compress the rocker arms, it is a lever that fits the arms. If the valve covers aren't leaking, don't take em off, slip this tool in and take the p rods off without taking the valve cover off.
Turns a 5.5 hour intake gasket job into 3 hours or less if you have air tools too

heres the first tool
http://buy1.snapon.com/catalog/item_Lg.asp?picFile=/59400/59356.JPG

heres the second, its the short one, they make one about 10 inches longer, but I see no need for it, they are easy to compress with it, and it has a spot for a ratchet for extra leverage too.
http://buy1.snapon.com/catalog/item.asp?P65=&tool=all&item_ID=78511&group_ID=1558&store=snapon-store&dir=catalog


A similar tool like that I think has been mentioned here, but some doubted if it work good, and on later models, if valve cover gasket would reseal good, etc. I can see that this tool would be a huge time saver though. Excellent tips you have here!

So, what's the final verdict on the gasket kits? The new Modified GM design, Felpro, Dorman (they even include the bolts and only cost $49.00), the thicker aftermarket ones ($91.00), some other? Which is best and won't re-fail. I'm just about to start this job and feeling apprehensive. Thanks for a great thread of info. -Andy

So, what's the final verdict on the gasket kits? The new Modified GM design, Felpro, Dorman (they even include the bolts and only cost $49.00), the thicker aftermarket ones ($91.00), some other? Which is best and won't re-fail. I'm just about to start this job and feeling apprehensive. Thanks for a great thread of info. -Andy

I have had good luck with gm, they now have the steel inserts in the break area, have new bolts, new oil pump drive seals, and valve cover gaskets if you need, their gray permatex is the best I have found, but it is ALL pricey too.

The felpro had the inserts before gm, they are good gaskets too.

I don't know about dorman, I have not used their intake gaskets, but have used other dorman parts and am satisfied with the product.
I replaced the hole upper intake plenum on a 4.6 mustang engine, they are prone to crack out, they are plastic, and the old design had plastic coolant runners, they now have aluminum, anyway, it was good, had the intake, and the new style mounts for the upper accessories, it was good quality, but I would guess that their parts are foreignif you care, probably felpro too for that matter.

The UTMOST important thing to do is tourqe with the revised specs, the gm gaskets have a papers with em saying to.
Over tourqe on the hardware is why they fail in the first place, it cracks the plastic and it goes from there.

Thanks for the advice jyount. That last part, about breaking the plastic, is one reason I'm leaning toward the Dorman set. I read these are made of metal. Yeah, I hate buying all that foreign garbage too. They are just killing us, economically. I'm a little pee'd off at G.M. for this problem in the first place, so I probably won't go with their set. Probably Felpro or Dorman set.
Have you used that tool you mentioned for removing the pushrods, without removing the back valve cover? Will the valve cover gasket re-seal with this technique? It sure looks like a tempting time-saver.

The Felpro Permadry plus lower IM gasket is made of a heavy steel backing and has triple seal rings around the water jacket. I would go with the Felpro over the Dorman or any others. Properly installed, I haven't heard of the manifold leaking again with Felporos kit.

My understanding is that the revised G.M. gaskets only use a small steel insert to prevent cracking the gasket in case of over tightening.

If I use either Felpro or other non-G.M. gasket, and these aftermarket gaskets are steel, unlike the G.M. gaskets, do I still use the revised G.M. torque procedure? It seems very slight, but then it does state to use locktite. -Andy

I don't think I've seen that tool before on here. Those corner bolts are a pain getting to even with a 3/8" drive crow's foot, especially on the later models that seems to have bigger manifold runners. I thought what was needed was a 1/4"drive to make room. Some bolt kits give you a 13mm head for the end bolts and give you a little more room to swing the crow's foot, but this seems like a better solution. I wonder if they have it in 13mm too? Maybe it'd help with the pesky power steering bolts?

Yes they do, the 10 is just the only one I needed, so the only one I got. They are actually in a set of four.

I think it is 10 12 13 and 14. They are around 50 bucks a piece I think, but they do the job well, and they are warrantied their hole life.

Thanks for the advice jyount. That last part, about breaking the plastic, is one reason I'm leaning toward the Dorman set. I read these are made of metal. Yeah, I hate buying all that foreign garbage too. They are just killing us, economically. I'm a little pee'd off at G.M. for this problem in the first place, so I probably won't go with their set. Probably Felpro or Dorman set.
Have you used that tool you mentioned for removing the pushrods, without removing the back valve cover? Will the valve cover gasket re-seal with this technique? It sure looks like a tempting time-saver.

Yes it will, I have done several just like that and had no problems, just put the permatex at the joint where the manifolds come together at the valve covers. I always wipe the gaskets clean with brake cleaner just for good measure. They are high qaulity rubber and have no trouble resealing.

My understanding is that the revised G.M. gaskets only use a small steel insert to prevent cracking the gasket in case of over tightening.

If I use either Felpro or other non-G.M. gasket, and these aftermarket gaskets are steel, unlike the G.M. gaskets, do I still use the revised G.M. torque procedure? It seems very slight, but then it does state to use locktite. -Andy


Yes they do, the insert is about 1/4" in the normally cracked corners. Its about the size of a pencil eraser. For the money, probably felpro, as they are cheaper I think, and better quality. But, for the record, if the tourqe specs are followed, the gm ones don't leak again either, as I said, the sealing material is not the problem, the cracked frame of the gasket is. The inserts, or the steel gets that problem.
As I said it is CRITICAL CRITICAL CRITICAL to tourqe the gaskets, slight over tourqe is the cause of the problem....

Dorman worked for me. I suspect any name brand will do the trick if installed properly.

Generally there is a good reason for providing a torque sequence and specification.
Follow it. To do otherwise is taking chances.

Dorman worked for me. I suspect any name brand will do the trick if installed properly.

Generally there is a good reason for providing a torque sequence and specification.
Follow it. To do otherwise is taking chances.

The question was, is there a different torque procedure for the aftermarket steel gaskets, than the one specified for the GM composite/with spacer gaskets. There is no spec sheet in the Dorman package and I haven't seen a Felpro instruction sheet for theirs (which looks identical to the Dorman, with triple raised sealing surfaces on steel plating). Thanks. -Andy

Dorman worked for me. I suspect any name brand will do the trick if installed properly.

Generally there is a good reason for providing a torque sequence and specification.
Follow it. To do otherwise is taking chances.

The question was, is there a different torque procedure for the aftermarket steel gaskets, than the one specified for the GM composite/with spacer gaskets. There is no spec sheet in the Dorman package and I haven't seen a Felpro instruction sheet for theirs (which looks identical to the Dorman, with triple raised sealing surfaces on steel plating). Thanks. -Andy


Yes the revised torque spec applies to all the replacement gaskets, Dorman and Felpro. I don't think the GM gasket has a different torque spec, higher or lower. The new torque spec is the same and applies equally to all revised gaskets regardless of brand.

I haven't used the Dorman, but it might be a Chinese knock off of the Felpro. I believe Felpro comes with a torque spec sheet and a few extras over the Dorman but you have to get the bolts separately. The Dorman bolts used with the felpro kit would be fine. Some people say the Dorman worked OK. Heck for all I know they might be manufactured in the same place, but it's a Felpro design andwhen replacing a gasket so critical for a few dollars more I'd want the Felpro name in case Dorman is a cheaper knock off.

I just got the 3.1L put back together for my 2001 malibu a couple of weeks ago. I used the Felpro gaskets (purchased from AutoZone). The gaskets I purchased were metal with rubber compression areas. They seem to be very sturday and line up accurately enough that I haven't found any leaks.

First of all I’d like to thank every single member who posted to this thread. This thread was an inspiration for me to approach this job. Never would I even start if it wasn’t for you guys.
The car I was working on is a 2000 Buick Century. I’ve got it for $500. All shops that I took it to suggested junking it because the repair would cost way too much. Oh well… they were VERY surprised when I showed them the car a few days ago!
To begin with I purchased a set of Dorman gaskets which came with plenum, lower intake gaskets, 8 bolts with preapplied threadlocker, oil pan gaskets, 3 different orings and a few other little gaskets. I only used EGR gasket out of those. $50 for the set. I also got a 94pcs set of craftsman tools off ebay for $70, a SnapOn electronic torque wrench off ebay for $200, oil, oil filter, oil wrench, oil itself, 3 bottles of antifreeze, a bunch of new clamps, vacuum hose and some other hose which I never used. Also I’ve got that easy push rod removal tool off ebay for 18 bucks, WD-40, 3 cans of engine cleaner (it was real dirty), 6 rolls of bounty, BLACK! (important) RTV a bottle of acetone, this thread printed out and a Hayness Manual. I also needed a throttle body gasket ($2.50) and in my case the spark plug removal tool (5/8) with a long extension. I also used a few other tools such as flat screw driver and pliers… The most important is to have a digital camera. If its your first time doing this job – don’t even start without it!!! Take as many pictures as you can… later you’ll see why!
Anyway, the job took me 10! days in total, working about 4-5 hours a day + constantly going back and forth to the auto parts store. Cleaning was a major issue because the car I purchased had the problem (antifreeze was leaking out of the engine only, no mixing with oil thank god) for a while and the engine accumulated a lot of grease and dirt. I must admit I removed some parts that were not needed to be removed for this repair.
Removal was fairly easy; you definitely need good American tools to unscrew some rusty bolts. A few pipes got stuck an took time to pull out. TAKE PICTURES!!! Otherwise you’ll be lost!! I needed pictures and my dad’s Buick to put that all back the way it was.
Don’t forget to get rid of oil and antifreeze before you remove the metal parts.

While doing the repair I found the source of my Service Engine Soon light. When I removed the plenum I discovered the horseshoe part of it that’s connected to EGR was clogged with carbon deposits (which I learned is a common problem). So I cleaned that
NEVER DID I NEED TO CATCH ANY ORINGS!! In fact, the place where the fuel oring sits did not need to be unscrewed in my case. All I needed to do was to pull the fuel rails with injectors out of the lower intake manifold and place them on the side with fuel lines still connected
Cleaning the surfaces in contact with gaskets is important and took me some time… but they all looked like mirrors at the end. I also cleaned every single part that I removed (which took me about 6 hours).
As I said I was using the GM tool that easily lifts up the rocker arms so that you can take out the push rods (watch the video on youtube). I used vacuum cleaner to get rid of any particles that fell into the engine while I was working on it. I practiced putting the lower intake into place several times before I actually did it with rtv and gaskets in place.
When the lower intake was back in place I screwed the new bolts to the new GM specs. Couldn’t reach 2 diagonal bolts with my torque wrench so I torqued them by using the feel of those which I was able to reach.
Plenum was torqued to specs as well. Make sure you follow the sequence!
Put all parts back into their places, connect the hoses, pipes and put the fluids back in.
Double check everything and you’re done.

What went wrong in my case:
Even though my car is 2000 I have an older engine version with EGR valves on the back and front of the engine. I broke the vacuum lines when I was removing them.
I discovered the piece of square on my tensioner in which you are supposed to stick your 3/8 wrench is broken so my tensioner had to be completely removed to take the belt off.
My heater pipe did not unscrew but was simply a part of the lower intake manifold. In order to fit it over the bolt that was holding it in place I had to bend it a little bit… and it was too much for it to take so it broke and I needed a tight fit connection to fix that.
I broke the EGR-to-exhaust pipe which is made of some soft metal alloy. It’s about 90 dollars at the store so I had to go to Home Depot and find some copper pipes of the same diameter and construct my own version of that AIR pipe as it is called. BE CAREFULL with it!
And finally, something that took the last 3 days. I put everything together and started the car. It only cranked but did not start. I was ready to loose my confidence. My dad told me to check the sparks and there it was… I had no spark… at any of the spark plugs. Everything related to spark plugs has been checked (spark plugs, wires, coils and even the plate with microchip) by putting that stuff on my father’s car and checking if that one starts. Parts were fine. Eventually I read another thread which mentioned the crankshaft sensor could cause the problem of having no spark. I located the wire and the sensor itself (back of the engine towards the firewall, closer to the belt side). I disconnected the purple and yellow wire and pulled it. Guess what!! The protective plastic melted and the bare wires were touching each other. I replaced the insulation, connected the wires back and the car started!!! By that time no one, even me believed I would ever move again by itself!
I added some more antifreeze and a few minutes later the engine was idling smoothly and quietly. No knocking, no ticking, no rough idling and most importantly, NO LEAKING! A week later everything seems to be fine and my 3100SFI, like one of the bloggers said, is purring like a kitten.

I just finished my IMG replacement. Since I found this thread to be very useful, I thought I would add my experience. It took me longer than most, but I wasn't in any hurry since I had alternative transportation. It took me about six nights and two weekend days.

Some advice -

1. Get yourself a magnetic retreiver and a small flashlight. I can't tell you how many times I dropped something and had to fish around to retrieve it (see #7 below).

2. Folks are right about the digital pictures being helpful. Make sure that you take a few from the firewall looking at the back of the engine. I found that I wish I had taken a few more from that angle when I was routing the sparkplug wires and main wire harness.

3. When you are removing the fuel rail, everyone says watch for the o-ring gasket, I didn't have any problem, but I bled the fuel out of the rail like the Haynes manual says to do. If you don't have the manual, there is a nub on the end of the rail by the power steering pump. It is probably covered by a rubber cover. Once you remove it, it looks like a tire valve stem where you add air. Just push in the middle pin like you were letting air out of a tire - but you get gas instead. Make sure the car isn't running and the battery isn't connected. It wasn't very much gas that came out, but the car had been setting for a while, so much of the pressure was probably already gone.

4. When you get to where you are removing the fuel injectors and the rail, it takes a pretty good pull to get the injectors out. I tried to just pull it out like the manual says, but after twenty minutes of messing with it I used a carefully placed pry bar.

5. When you are trying to get the rear valve cover, bottom drivers side bolt out, do yourself a favor and buy either a 1/4 inch extension, or I bought a 1/4" square 3 foot raw iron bar (about $3) from Home Depot (hardware section) and cut off a 4 inch section. I put it into a 1/4" drive socket and just used a wrench on the other end. It worked great. However, by the time I reinstalled it, I had purchased a 1/4 inch extension. It worked, too.

6. This one had me stumped for quite a while. The wires to the fuel injectors have a two stage fastening system. The Haynes manual just says to disconnect them. It isn't that easy. I had to go the local Chevy dealer and talk with a mechanic. To disconnect them, you have to lift the green part by grabbing the two ears and lifting, or if they are not accessible, take a small screw driver and wedge it just under the green and pull up. The green tab lifts about a quarter to 3/8ths of an inch. Once it is up, push the grey tab and pull up. You might have to partially pull the fuel rail in order to get enough room to pull the connector as the power steering pump is otherwise in the way. Or, you can pull the power steering pump before you try to remove the fuel rail (FYI - that requires removing the engine mount bracket and lifting the engine with a jack).

7. Push rods - keep them in order like they say. When you put them back, especially the first one, use a flashlight to see where it is going. I just slipped it in, released it, and it disappeared into the engine. Oops! The magnetic retriever pulled it right out, but that was a scary moment. When you get to the back, you won't be able to get a good angle to see where they go. Play around with it a bit and pretty soon you will find that when they are in the right spot, they sort of seat. Once you think you have one in place, pull it up about an eighth inch and then angle it slightly out of what you think is the "seat". Push down and it should sort of self direct itself back into the seat. If you don't get that seated feeling, you probably aren't in the right spot. Pull it out and try again following the angle of the head.

8. Buy a torque wrench. I bought two. One with a 1/4 inch drive and measurements in inch pounds, and one with a 3/8ths inch drive measured in foot pounds. I needed both when putting everything back together.

9. When jacking up the engine to pull the power steering pump (and replace the serpentine drive belt), I used the spare tire scissor jack and a one foot square piece of 3/4 inch plywood carefully placed under the oil pan. I couldn't otherwise find a place to get the jack lifting on just the engine. Make sure you have loosened the engine mount plate (loosen only!) so that you can see if you are lifting the whole care or just the engine. Monitor the space between the top plate and the bottom of the head of the bolt you loosened to see if you are making any progress in separating the two. You don't want to be lifting the entire front end of the car by the oil pan! When you have some gap between the bolt heads and the top bracket, back the bolts all the way out and remove the top plate of the bracket. All you have to do is remove the top plate to get enough room to take the pump off and slip in the new drive belt. As soon as you can, put the bracket back on, tighten it, and remove the jack (its a safety issue).

10. And like someone else said, take care of the spark plugs, spark plug wires, serpentine belt while you are at it. The new wire set I bought at NAPA came in different lengths than the OEMs. I just used some zip ties to hold the wires when I couldn't get the original wire holders to work on the backside of the engine. I didn't pull them very tight as I didn't know whether bundling and crossing the wires that tight would be an issue.

This is valuable info. Thanks to all for this. I can't afford to have a mechanic charge me for this. I'm unemployed right now and this repair bill would kill my budget.

I will be replacing the IM gasket and etc. soon. My leak is very slight at this time.

My "dumb question"is this:
I have some lifter noise and I'm not sure which lifter it's coming from. Would this be a good time to address that issue? I've got 180K miles on this puppy with no end in sight. Outside of the lifter noise and coolant leak this 3.1 V6 is hard as a carp. Any guidance/info would be appreciated. I've gained ALOT of info/knowledge from this forum.
Thanks again very much.
Bill

Yes you should try to fix the lifter problem at the same time. You will be well into the engine, so you might as well take a look. Hopefully the issue will be obvious when you start taking the push rods and lifters out.

I didn't phrase the question correctly.
Question 1: When I have the IM removed how can I tell which lifter is making noise or am I looking for freeplay in the pushrod travel?
Question 2: Can these (lifters) be replaced without further disassembly?
Thanks very much.

Hello Everyone,

Like so many other users on this post, I wanted to say thanks to everyone for their input. I normally don’t sign up for different forums, but I found this so helpful I needed to say thank you as well as add what I learned from my experience of doing the infamous GM Lower Intake Manifold gasket (IMG) repair.


All the advice I found on hear was right on and very helpfully in getting prepared for the long task in front of me.


In short the two things I learned in addition to the advice given here is, triple check which gaskets are for your specific application, since most of the gasket kits include multiple gaskets for different GM engines. Make sure you old one’s line up exactly with your new one, I did not do that and ended up with a vacuum leak. Also, like everyone else stated, make really detailed notes on where your wires go, and I recommend taking the time to paint a couple of your items.


Here’s the long story. In addition to everyone’s recommendations I also replaced all my water/heater hoses, the overflow tank ($23 rockauto.com) my radiator ($83 delivered from radiatorbarn.com), the belt tensioner pulley and idler pulley also got replaced. Also because you are tearing down so far and are taking the time to clean everything and remove all the carbon deposits from your lower and upper intakes, I also picked up a can of Chevy Orange engine paint ($6). I sprayed the valve covers and the upper intake, it’s not a 350, but it sure looks cool. When I was at the parts store getting more coolant to top off after the job was complete it made everyone do a double take at my little family car.


In addition to thanking everyone for posting their knowledge, I wanted to add a couple things I learned from the project as well as maybe help those three other people I saw on this thread looking for help with a vacuum leak after replacing their IMG gasket. After completing all that work, cleaning the compartment real nice and painting the upper engine she started up great, but would not idle. My first thought was the lower gasket did not seat correctly and I had a vacuum leak, but I also thought it was possible I damaged a sensor or broke a hose and or wire. First I tested the throttle position sensor (TPS) and got a resistance of 1.9ohm at 20 OHM setting. I replaced the Idle Air Control (IAC) valve because it was loaded up with carbon deposit. I knew the throttle body was cleaned very thoroughly but none of these things solved by idle problem. To make things more difficult I had no OBDII codes thrown, which felt kind of good, but at the same time gave me no leads. I had replaced the PVC, the hoses to and from the PVC (including the u shaped one on the EVAP purge valve) I also replaced the PVC 90 degree elbow with a spark plug boot due to the old one crumbling in my hand. I put all the old part back on (duck taped the broken ones) and the vacuum leak continued. Next I unplugged the EGR and the car idled, it idled rough, but she ran. I was certain it was the EGR, I could only find articles on how to test is with a hand vacuum pump, but not with a multi-meter. I replaced it anyways, and my problem remained. Finally I tested EVAP purge valve (connects to EGR and PVC hose), I got a resistance of 0.3 ohm at 2k OHM setting, I knew that was good. My fear was I had to tear down again.
I knew for sure I had a vacuum leak, I just couldn’t find it. I decided to start the re-tear down, at least to the top intake manifold. First I sprayed starter fluid around all the lower and upper intake gaskets, if the engine revved up I would know where my problem was, nothing. I was kind of glad, but also more confused.

Then started the tear down. I Started removing the throttle body, air box, coil packs, etc. I asked my friend who was a huge help if he saw how the throttle body intake gasket looked, his response was “what gasket?” We found the gasket still attached to the throttle body (TB), it was hanging cock-eyed on one bolt still after removing it, but my friend noticed that the gasket partially covered up a nook on upper part of the throttle body. How he saw that I don’t know but we looked at all the gaskets that came in the kit, and two of them were identical except for one gasket had a slight cutout for that notch on the throttle body. The mistake I made was I placed the “new” throttle body gasket over the old one and said yup the holes line up, the outside looks the same, and the hole in the middle is the same. What I couldn’t see was I was also covering up a small notch in the old gasket that allowed air to get to the EVAP purge system, hence we were choking the vacuum and the car would not idle. We replaced the TB gasket, bolted everything backup and she purred like they day she rolled off the GM lot.


Another mistake we made was, we did not realize the male connector on the end of the fuel injector harness needs to come back out under the upper intake on the passenger side. It naturally wanted to lay and come out on the driver side. Instead of tearing down the upper intake, we cut the connector off, spliced in some wires to the length we needed. Taped the whole thing up, then got some wire loom to protect it, taped up the wire loom, then zip tied it along the metal coolant line back over to the passenger side of the motor to reconnect it.

In the end everyone comments on here allowed us to do a phenomenal job, other than out two mistakes it was a huge success, and I must admit that Chevy orange paint job on the valve covers and upper intake looks awesome against the black wire looms, black hoses, and the black oil cap.
In addition to what other have taught me about doing the IMG gasket, I hope others learn that they need to triple check which gaskets in their kit goes to their car. I believe my kit included gaskets for the 3.1, 3.4, and maybe the 3.8 used in several front wheel drive Chevy’s, Olds, Buicks, and Pontiacs. Even though I thought I paid attention to people notes about marking everything, clearly I should have put more labels with meaningful notes on where the wires should go.

I have the UIM off, altnator, and all the bolts from the LIM (10) but I can't get the LIM off - is it that difficult? A diagram of the LIM shows that there are 12 bolts but I only see 10!? What up wit dat? :iceslolan It's not budging...

Nevermind. I got it off. There are two bolts, one on each side that are hidden in the LIM channels. Mine were covered with oil so I couldn't see them. Now I have the required 12 bolts removed. Here's a link with a better photo of the LIM and those two bolts.

http://www.2carpros.com/questions/buick-lesabre-2001-buick-lesabre-3800-intake-gasket-replacement

Anyone find or make any how-to videos of this procedure on youtube?

I do all my own oil changes and brakes and such and I've replaced a water pump in the past. This would be the most difficult project I've ever tackled. Do I just go for it or hire a professional?

I would highly recomend getting a manual and doing some research before you attempt this job. It can be intimidating if you have not done it before. I have had several towed in that people started, then decided it was too much for them.

If you have successfully done a water pump and routine fluids and filters replacement and maintenance you have the basic mechanic skills needed, provided you can work form written shop manuals and instructions. However, the LIM gasket is a much more involved undertaking and digs much deeper into the engine. If you are experienced and have the needed parts and tools and a good, warm garage, it can take the better part of a full day.

Works best if you have a FSM, or at least a good on line manual such as AlldataDIY, and study up a bit before you start. Read all the posts here and elsewhere regarding doing the job. (IMHO the typical Haynes or Chiltons manual is not adequate for this job.)

First time? than plan for at least 16 hours time actively working on the car. Take lots of photos in sequence as you disassemble the engine so you can study them to help get the parts, wiring, hoses, etc. back in the right locations. And store the parts you remove in a good, safe location marked as to where they came from and thus go back.

Once you open it up, the car is dead until you complete the job, and you may find you need additional replacement parts halfway through the job - e.g., if you break an injector. or need to replace plugs or wires.

However, DIY can save you several hundred dollars.

Hello and Thanks to everyone!

My son and I are about to do this job tomorrow- and we are so glad to have the advice and precautions shared on this post!

Does anyone know where to get the best step-by-step instructions? I am planning on getting the Haynes Manual, but are there also any online?

Again, Thanks!

Hello and Thanks to everyone!

My son and I are about to do this job tomorrow- and we are so glad to have the advice and precautions shared on this post!

Does anyone know where to get the best step-by-step instructions? I am planning on getting the Haynes Manual, but are there also any online?

Again, Thanks!

Sign up for the repair manuals at autozone.com or alldata

Short of buying a Factory Service Manual, AllDataDIY.com is among the best - far better than the typical Haynes manuals. And have a camera available to take many pictures as you take it down so you can get the precise routing/parts placement correct as you put it back together.

Make sure to pay attention to the push rods! They are different lengths! Exhaust rods are longer than intake rods!

Hello and Thanks to everyone!

My son and I are about to do this job tomorrow- and we are so glad to have the advice and precautions shared on this post!

Does anyone know where to get the best step-by-step instructions? I am planning on getting the Haynes Manual, but are there also any online?

Again, Thanks!
I'm assuming you have the 3.1. Go to d-tips.com and click on the "Articles" drawer on the toolbox at the left. You can read about the 3.4 intake replacement. I read this and this made alot of things clearer to me. If there are any, and I mean any things that you are not clear about, you should ask here and don't guess while you're doing the job. There's too much at stake to make a mistake. Good luck.

I have a 2000 Chevy Venture and did the gasket about 4 years ago. Looks like it has come back. Loosing coolant, pressure test is OK, carbon vapor test is OK. Has a rough idle and the temp. gage wanders between hot and cold at times.

Wish me luck!

I have a 2000 Chevy Venture and did the gasket about 4 years ago. Looks like it has come back. Loosing coolant, pressure test is OK, carbon vapor test is OK. Has a rough idle and the temp. gage wanders between hot and cold at times.

If you used a new, good gasket (e.g., metal frame) I would not expect it to fail that fast. If you cannot find obvious evidence of gasket failure, such as coolant in oil or oil in coolant, I would be sure to check for other issues as well before tearing into the engine again. Rough idle and wondering temp gauge, and coolant loss could be something else, such as a failed temp sensor, or perhaps a couple thing like a leaking water pump seal and some other sensor.

Finished an overhaul and the only issues I had were with the fuel intake and the intake manifold RTV seal bead. took 6 hours to redo it. The o-ring got crushed & fuel poured out, and the RTV seal on both ends was inadequate & leaked oil. Got to watch that o-ring - always have new ones handy, and a good amount of RTV has to be pushed deep up into the base of the manifold gasket at the corners before squeezing a generous 1/2” thick bead on those ‘S’ mating surfaces. Not the best design imo, but it’s dry now & runs fine.

Alot of good advise in this thread. My engine seems to be leak free now.
Hope you( tczer34)found the fastener holding the fuel lines to the engine block ok. My big gripe was the damn inlet fuel line O-ring. It popped out Both times, :banghead: and I had to go to the dealer to get another..8 bucks. Ouch:banghead: