Write-Up: Lower Intake Manifold (LIM) Gaskets

If you want pics:
https://rivperformance.editboard.com/t4250-write-up-lower-intake-manifold-change-on-a-95#54603

Its series one, but the physical "things" are very similar.

Changing the LIM was one of the first "big" jobs that I did myself. I spent awhile preparing for it and did it over the space of a week. That said, now I can and have done, LIM gaskets on both series one and two, and can blast through it in 4 hours or so.

If you want to save money and are mechanically inclined, its not too bad. Must have tool is a torque wrench and basic hand tools. Its really up to your comfort level. If you've never done your own plugs and wires, then LIM may be a bit much for you. If you've done plugs, wires, oil, valve cover gaskets, etc already then go for it.



That said, if you are trying to track down an oil leak that leaves traces on the driveway, likely your LIM is not the culprit.(though it is a VERY good idea to get it done. A leaking LIM lets coolant into your oil and results in a done engine) Likely the oil is your pan gasket or valve cover gaskets.

To answer your question about the gaskets, LIM gaskets sit between the block and the LIM and the heads and the sides of the LIM. Valve cover gaskets sit between your valve covers and engine heads.

If you want some series 2 pics, I *might* have some pics from when the 98 got done.

Don't forget a strong back (or perferably a buddy) to help lift the supercharger and the plenum off the engine! I brought the wife out to help me do that. I searched this site first, and then made a big ass parts list, dropped a couple hundred at the parts store and went at it. I got it done in a night, but it was a long night! I had no manual at the time.

VegasScott

Love how every vacuum fitting or line I remove broke or cracked today. Guess I'll be picking up an assortment of size and elbows tomorrow. Hopefully I can figure out where they all go to. Took pictures so that should help.

Going to go ahead and replace the spark plugs and pull the rear valve cover which I have a spare gasket for from 3 years ago. All this makes getting at the heater core hoses much easier.

Can anyone confirm that the 97's have this? I was pretty sure I just pulled an elbow off of there with one line running to a solenoid towards the firewall. In fact, I can't find any T fittings in my garage.

I asked that very question during my repair....

Mr.Riviera wrote:

BMD wrote:

Thanks for the link 98Riv. Three questions...

Haven't found the P/N # for the large plastic elbow yet. ( yellow in pic )

Instead of a "T" coiming out of the manifold ( as in the pic below ), I have an elbow?! Is that only on a 96? Obviously that should be left alone aswell?



Valve cover gaskets- GM: 24503937 : Fel-Pro: VS 50465 R. Are these the revised valve cover gaskets, what are they made of?

The coolant elbow can be picked up from http://www.zzperformance.com/grand_prix/products1.php?id=370

On the 96's our vac lines are arranged differently than the 97+ due to the vac controlled transmission. We have just an elbow where the 97+ have a T. However, a T will work on a 96 should you ever need to free up another vac port on the blower or loose one in a swap.

As for the VC gaskets, i dont know what changes were made, but if the prices are the same, go with the updated version. There was a recall for other 3800's to have the gaskets replaced. If you get the elbows from zzp, they also have the proper gaskets for $14 each or $27 a pair.

I just came across a picture in another thread showing the same connector I have and it's not a T fitting. My car is a 97 though.

Quick question:

I opened my felpro supercharger gasket set. It came with two identical gaskets and the yellow o-rings. My assumption is that one gasket goes face down and the other face up. Is that correct?

Hmmm, my felpro gasket set didn't come with two identical gaskets? This is what mine had...

Not sure why they would have two identical gaskets?

Sounds like you got two for the price of one! Mine always came the same as BMD's. You only need one supercharger gasket.

If you have two, can I buy the other one from you?

I better take another good look in the box for the smaller gasket as I didn't see it. I did get two of the larger gaskets though.

If I can figure out a way to ship it without breaking, I'd send it to you for the cost of shipping.

I'll PM you. Thanks!

manofmany wrote:

I better take another good look in the box for the smaller gasket as I didn't see it. I did get two of the larger gaskets though.

If I can figure out a way to ship it without breaking, I'd send it to you for the cost of shipping.

Priority Mail flat-rate box, perhaps.

happy shipping

Albertj

Having trouble with two connections..

Where does the 3rd fuel connector go? It seems to have a rubber elbow on it

Also, on the bottom of the evap switch, there is a connection. Diagram says it goes to the evap canister on firewall?

i think you are answering your own question. The 3rd line on the firewall goes from the evap purge valve to the evap canister at the rear of the car.

I was confused because there were three nipples. Apparently one just contains an elbow and vents. Thanks for the help. Car is back together and running pretty good. Think I may have some slight vacuum issues but I'm going to have the shop go through the system when they do the heater core. Can't spend any more time under the hood this weekend.

Anyone?
> Can LIM bolts be reused? A source if not?
> Can the SC gasket be reused?
Thanks in advance

denim wrote:

Anyone?
> Can LIM bolts be reused? A source if not?
> Can the SC gasket be reused?
Thanks in advance

i reused mine and they are holding fine. i think tq spec and order are more important. SC gasket can not be reused. it will come off in pieces with a razor blade. even the zzp garloc ones will fall apart with oil exposure and time.

Thank you!

Agree, reuse the LIM bolts. They don't get tightened very much: Use red thread locker (GM 272 or equivalent) and torque to 11 lb-ft (132 in-lb).

Relevant crosspost from here:
http://www.gmforum.com/1992-1999-91/doorman-has-new-aluminum-coolant-elbows-%5Bx-post-bville-pro%5D-303623/

Part # 47065hp
http://dormanproducts.com/advance/p-52351-47065hp.aspx?year=2006&make=BUICK&model=LUCERNE%253A%2520CX

About frigging time someone did these in aluminum.

That's awesome. In defense of the plastic ones, mine held fine with no leaks for 246k miles. But if you're taking the LIM on & off frequently, this metal part makes perfect sense.

(Keeping my brand new plastic one for as long as I can!)

I'm curious why plastic was chosen as the replacement.

GM plastic = better quality than HELP! replacement plastic. Good price on the aluminum though at $8.50. They are aluminum, so expect some corrosion.

Karma wrote:

Relevant crosspost from here:
http://www.gmforum.com/1992-1999-91/doorman-has-new-aluminum-coolant-elbows-%5Bx-post-bville-pro%5D-303623/

Part # 47065hp
http://dormanproducts.com/advance/p-52351-47065hp.aspx?year=2006&make=BUICK&model=LUCERNE%253A%2520CX

About frigging time someone did these in aluminum.

Yep.

denim wrote:

I'm curious why plastic was chosen as the replacement.

Plastic was the original too - cost and corrosion are issues. Riv block is iron, can have a galvanic reaction with aluminum parts, I am told, if the coolant gets acidic for some reason for instance.