I noticed an increasing leaking of coolant, so much that it was a puddle every day, whether the car was used or not. Took awhile to find the exact location of the leak, turns out it was right below the throttle body where the engine block mates with the LIM.

Heres the story in pictures. Note*** this is at 210,000 miles

Got my gaskets and sealant in order:


Next removed the plenum, LIM and TB in one piece.


A Look at the TB and its gasket, looks pretty healthy to me



A look at the plenum gasket


A look at the LIM and its mating surfaces on the heads




Tell me this one isnt bad news?? BTW my oil looks like normal oil, NOT like milky chocolate.


What do you guys think? DO those gaskets look like they have failed? Those of you who've done this, this what your LIM job looked like? Any opinions welcome. thanks.

-Patrick

Those gaskets look pretty good for over 200k, but it was time. And they are the factory-installed OEM gaskets. Im'ressive life. Note that it'* impossible for a leak of coolant at the location you mentioned between the LIM and the block.

The #1 runner is always cleaner on an L27 like that. Normal. It'* farther from the PCV and EGR return.

Consider yourself a little lucky. The L36 won't come apart in a big chunk like that. There are two hidden bolts under the UIM for the LIM.

Thanks for the info willwren, i was a little worried why the #1 didn't have carbon residue built up. Wherever the leak was coming from it ending up puddling in the engine on the block below the tb. And since all the LIM gaskets were moist looking i just assumed it was coming from there. During the actual tear down of things i discovered some of the LIM bolts were so loose i could move them with my fingers alone, so im sure that contributed to the leak. But now they have a thread lock on them and are properly torqued.

Im happy that there are no more puddles!

Thanks for posting thos pics . I am getting preparring myself for this project on my 1998 L26 with 61k miles . Mine so far only has slight leak under pressure near the the TB . I noticed that you chose the Flepro gaskets instead of the GM alumiinum gaskets . Was this for a reason or just a matter of convenience ? . Any other comment or tips ? - Thanks

rkpatt, that'* the L27 engine, not your L36. The L27 has no need for the redesigned aluminum gaskets.

While the procedure is similar, the problems between the two motors really aren't.

oops - got it
[quote="willwren"]rkpatt, that'* the L27 engine, not your L36. The L27 has no need for the redesigned aluminum gaskets.

While the procedure is similar, the problems between the two motors really aren't.[/

You didn't happen to change out your valve cover gaskets and grommets at the same time, did you? Much easier job to do when that LIM is out of the way...at least for the rear head (front one you can do at any time).

Funny how these gaskets, when they fail, look like they fail around the coolant ports. I also just wondered something...would it benefit gaskets like these to have steel or aluminum bolt sleeves to keep from overtorquing?

Since doing the repair, the engine has been dry as a bone.

To answer your question, no i did not change the valve cover gaskets or grommets. The valve covers were not much of an obstruction at all, having/using a universal joint socket accessory helped alot. Now that i know exactly how to do it, the procedure is pretty easy, i could prob do it again in about 1/4 of the time.

My LIM gasket was weeping coolant in several places making it appear that there was a leak from the valve covers. There were some torque specs found here on the site that did not agree with my factory shop manual, so be sure to double check.