Thread: Progress of LIM gasket replacement...at 231,000 miles

First off, I'd like to thank the grandprixforums community for all the information that's been posted. I've accessed a lot of useful information using the search function. Kudos to all of you guys!

Now, to the topic at hand, I got the LIM removed yesterday, started the day before. Wasn't too difficult, but I did find it time consuming. Also found it easier to remove parts entirely if they got in my way, rather than trying to work around them. Busted off both of the exhaust flange bolts removing the exhaust pipe, but I already have new ones on the way. I've also decided to replace the valve cover gaskets, coolant elbows, thermostat, etc. since you guys have suggested it to other visitors. I also took your advice to refrain from trying to replace the head gaskets.

The LIM gaskets were the factory originals at 231,000 miles, and honestly they didn't look half bad. The material next to the channels didn't look that worn at all. I don't know what this means in terms of how the car was taken care of, but I already have a set of felpro metal/rubber replacement gaskets ready to be put in tomorrow.

The coolant I drained out of the radiator prior seemed kinda viscous, I'm guessing because it hasn't been changed in awhile. I intend to flush it all out when I get done and the weather warms up. Also replacing a few radiator hoses (upper/lower/reservoir).

Also got the nose of the supercharger apart, and the coupler was a little worn, but didn't have too much ovaling. Gonna replace it anyway.

I now have quite the assortment of bolts and such, intimidating to look at, but I'm hoping it won't be too hard to remember where everything is supposed to go. I tried to organize the bolts as I pulled them off.

Not sure I can say anything else, any suggestions before I button her all back up?

Originally Posted by dsmuts

x2 on why you removed any component of the exhaust.

One of the write-ups said that removing the crossover pipe was necessary to remove the egr crossover pipe. In hindsight, I should have just worked around it, but it is what it is.

Anyway, I did the valve cover gaskets, and the front one was in decent shape, must have been from the engine fire recall. The rear one was so flat, it's a wonder it was sealing anything at all. In fact, there were signs that it may have leaked at one time in the past. New gaskets now, though.

The LIM gaskets showed no signs of immediate failure, and I drained the coolant before I took the engine apart. I didn't see any coolant spilling out of the LIM or supercharger while I worked. I wouldn't think the oil would be contaminated. I already planned to change the oil once before starting it up, but don't you think 2 oil changes is overkill? I'm curious about your reasoning.

Also, my new t-stat (stant) doesn't have a bleeder hole. Should I drill a small bleeder hole, or should I be fine?

And thanks for the input guys, it's coming together.

Not arguing with you guys, but the thermostat I pulled out had a tiny hole through the plate, while the new one does not. I'll take pictures for you guys at some point. Then again, it should be a direct replacement so I shouldn't have any problems.

And I see your point, fivefinger. I'll dump the current oil, put in cheap oil, run it a bit, drain that, and then fill with the oil and filter of my choice, as you suggested. Thanks.

Originally Posted by copgtp

I think that's pretty apparent Cam, but what the OP describes is the exact description of a drilled t-stat. He said in the plate, I'm sure it looks similar to this:


As I said, it's not necessary.

Yes, this is precisely what I meant. I'm aware of the bleeder screw on top of the thermostat housing, but I was referring to the hole copgtp pointed out. Didn't mean to cause a stir, I was just curious about the differences. Thanks for clearing that up. Also, whoever replaced the t-stat last didn't put a gasket on the housing. Surprised it didn't develop a leak. I already have a new one, as well as a new gasket/ring for the thermostat itself, so all should be well.

Anyway, got the LIM back on today, not putting the back on until I receive my new coupler. (Old one wasn't too ovaled out, but since it seems to be a common problem, I'm replacing it since everything is all apart anyway. That S/C oil is pretty rank.

A friend of mine is gonna have a look at the fuel injectors. Nothing wrong with them AFAIK, but since I have them out anyway, he'll flow test them for me. I'll probably wrap everything up next weekend when I have all my new parts, including new spark plugs. Assuming I get everything run, she should be running great!

Guys, some OEM thermostats have a small hole with a caged checkball in it. I don't have one on hand to show you but my 04 GTP had one like that and it was factory installed.

Originally Posted by OH4CompG

Guys, some OEM thermostats have a small hole with a caged checkball in it. I don't have one on hand to show you but my 04 GTP had one like that and it was factory installed.

Yes, in fact, I believe the t-stat I pulled out had a check ball as well. Possibly the factory original thermostat?

And I had no idea about the seal, copgtp. It gives me more reason to suspect the thermostat is original...and I believe it still works just fine. Still, can't hurt to replace, I figure.

Originally Posted by BillBoost37

I've seen some factories and even aftermarket T stats (stant) with a hole in them. Common enough to find it. You don't need it, just ensure you bleed the system well.

On the bolts, post up pics and we can tell you exactly where they go if you have any questions at all.

On the exhaust bolts. The NA motor has a bracket from the TB to the LIM. It's technically correct to pull the exhaust to get at the lower bolt of that bracket. I've snuck around it or pried it out of the way instead. Can understand why it might come off for the EGR tube and or the bracket if you are NA

Thanks for the clarification Bill, I think I'm doing well as I've had no trouble locating bolts to get things taken apart and put back together appropriately.

I regret busting off those exhaust studs, I have a replacement set on the way, but extracting those rusted things is probably going to be a PITA. (The studs were on the firewall side of the connection to the crossover pipe.) Using a small mirror, I noticed that the studs have small square-shaped nuts on the back side. Due to all the rust, I'm not sure if these nuts are something I should try to remove. Should I stick to extracting the studs, or do you think I should use a large socket and try getting those nuts off? Not a whole lot of room back there, but I think I could get a breaker bar on it if I had to.

Originally Posted by BillBoost37

The nuts are welded to the flange. Either air hammer them off and use nuts or drill them and tap them. They should be 8 x 1.25 thread.

Thanks Bill, that's immensely helpful. I think drilling/tapping will be the best option if I can't get the studs to come out with an extractor.

Finally got it all back together this weekend, defeated the stubborn exhaust studs, changed my coolant, oil, and t-stat and all that good stuff. She runs well for the most part...some surging at idle, but I believe that to be the result of a faulty MAF sensor (P0102 Code). Other than that, seems great... no signs of coolant anywhere it shouldn't be or anything like that. Thanks to everyone that contributed advice. I plan to take care of the spark plugs/wires, trans fluid/filter change, and a handful of other things in the near future. Oh, and a link to my thread containing pictures...

http://www.grandprixforums.net/pictu...tml#post757278

Won't be long until it's Summer and I'll be ready for a few mods.