Hey guys, I've been told my upper intake manifold gasket needs replacing. Anyone have any information?

 

6th gen? pretty simple

I think there is 6 maybe 8 bolts holding the UIM down,you can unclip the wireharness clips move it out of the way,shouldnt be much more than that,if you do this it would be a good idea to go ahead and take the TB off and clean everything and put a new gasket on the TB as well,i think the main bolts are 10mm or 8mm

 

I'm surprised with as common as this job is, we don't have a good how to guide in the tech info section

The job is easy, especially on a 3800. I've done it a few times. A lot of the stuff I feel is pretty straight forward. There are a lot of videos on YouTube about this, here's one I found that looked "start to finish". Just take your time.


Recommendations:
- Get the Fel Pro metal core LIM gasket kit and doesn't matter much on the UIM gasket kit (I believe I've used a Dorman most of the time).
- Get the torque specs for the lower and upper intake (especially the upper, it's plastic, over-torquing means damage).
- I pulled the UIM off with the T-body attached. This is handy to inspect the UIM! The UIM failure is where the EGR "stove pipe" is (the pipe is literally a piece of pipe sticking up on the UIM, I believe Dorman gives a narrow pipe replacement to ward off UIM damage). On two sides of the UIM are coolant ports, they take coolant in and out of the T-body. Place a finger over one port, blow compressed air in the other, watch around the opening for the stove pipe for coolant or air to blow throw. If so, the UIM has gotten brittle and damaged (common UIM failure that causes coolant to enter the cylinders). Frame 11:07 the guy points the EGR opening on the UIM.
- If the UIM is damaged, you have two options. One is replace the UIM. The other (and cheaper), tap the coolant ports on the LIM, plug them. I used stainless steel set scres, I've soon others use brass plumbing plugs (I think the brass plugs are better, NTP threwads are finer then the ones on my stainless plugs). For extra insurance, JB weld the coolant ports shut on the UIM.
- As mentioned, change the T-body gasket (should come with the UIM gasket kit in most cases).
- Even though the guy does the job without pulling the tensioner assembly and the alt, I recommend doing it and change the coolant elbows while you are at it (Dorman now makes aluminum elbows, gets rid of another plastic failure point).
- Clean as much as you can. The cleaner things are, better the job is AND in some cases, improves car performance.

I think that's about it. I hope it helps!

 

Okay, so I should change the throttle body gasket too, got it. Now I don't need to replace the lower intake manifold gasket though? Or do I always to both? (My coolant elbows are also okay; I replaced them last year and they're holding up great with the RTV sealant.)

 

Upper Intake Manifold bolts 10 Nm (89 lb in)
Lower Intake Manifold bolts 15 Nm (11 lb ft)
Throttle Body Bolt/Nut 10 Nm (89 lb in)
Throttle Body Support Bolt 16 Nm (12 lb ft)

Felpro MS 98014 Taluminum lower Intake Manifold Gasket is $54 on amazon
Dorman 47065HP aluminum Elbow Type Heater Hose $10 on amazon
Fel-Pro MS95812 Plenum Gasket Set $37 on amazon

 

Let me put it to you this way about the LIM. If you are 80K plus miles, never did the LIM and already have to pull the UIM off, do the LIM.

It's only a few extra minutes to pull it off (there is no challenge, other then finding the "hidden" two bolts on the inside of the LIM in opposite corners, usually in a puddle of oil). And then one more thing to clean.

It's worth doing in the long run if you intend to keep the Monte.

 

Alright thanks guys, I don't have a torque wrench though, I've done all my jobs by hand. Is that okay? :/

 

Not for the UIM. These are brittle and plastic, if you over torque you can crack the UIM and you definitely don't want to under-torque.

 

Hello all.
I'm going to try and replace the upper and the lower intake gasket.
which kit should i get?
I now the metal one, but i cant find it for my car.
1995 z34.

 

i was also looking into doing this in the fall maybe the engine has around 70k on it so i wanted to get this done for sure, i was gonna order the dorman for the upper and the aluminum felpro for the lower im just nervous on doing this