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LIM gasket or Head Gasket?

F

Fahrenheit

New member
03 GP GT, about 100k on the clock. Shes burning coolant and the rad has a lot of black mud in it, I add a qtish of coolant every couple of weeks. No water in the oil yet. Little bit of white smoke out the pipes. Seems like there is some coolant puddles down where like the fuel injectors are. Right now I'm thinking its the LIM gasket, what do you guys think?


If it is the LIM gasket where can I find a good write up? A lot of people link to that youtube video of it being done but thats a SC engine and they are pulling the push rods and what not. Would really like a written article as well so I can print it out and have with me.


Also I know I should be doing this ASAP but do you think it can go till it warms up outside? Really dont wanna freeze out there. Also will burning the coolant make me fail emissions? I'm due in feb.


Thanks homies
 


Intake gaskets. If its already leaking that bad, you need to do it very quick or it will cost you a motor and more money. Pull it in a garage and get a space heat or something to make it not so bad.

Just follow the one video or the write ups in the how to section.

Just completely skip the rockers/pushrods parts and its all the same. Remove Fuel rail, UIM, then LIM, clean everything up, dump oil down the valley and bolt it all back together.
 
Well HomeSlice...you can hold out....maybe. No one can give you a definate answer. It's typically a LIM, and it sounds like you have confirmation of it being the LIM gasket.

I have not done a write up on it. The basics are
DRain coolant
Disconnect neg battery cable
Remove altnernator
Remove fuel rail
Remove UIM and TB
Remove 12 bolts from LIM... there are two that will be hidden below the pool of oil in the front driverside and rear passenger side of the LIM. INSIDE of it actually.
Clean surfaces

Read these both to understand why I recommend plugging the coolant ports.
http://www.grandprixforums.net/97-03-na-l36-uim-failure-60667.html
http://www.grandprixforums.net/how-mod-lim-46931.html
I would suggest plugging the coolant ports only. You could open up the end u bend if you wanted.

Replace gasket with some RTV in the corners where the rubber gasket meets the metal gasket.
Use a sealant on your LIM bolts (A teflon based works well)
Torque LIM bolts to 15ft lbs
Put UIM back on and torque to 87 inch lbs watching the plastic as you tighten. If it turns white and starts to break, that bolt is tight enough.
Clean TB with TB cleaner
Reattach TB
Put fuel rail back on
Put alt back on.
Fill and burp cooling system
If you lost water into the engine, drain oil. If not..start and run for a moment , then check the oil. If milky.. change oil.
 
BillBoost37 said:
Well HomeSlice...you can hold out....maybe. No one can give you a definate answer. It's typically a LIM, and it sounds like you have confirmation of it being the LIM gasket.

I have not done a write up on it. The basics are
DRain coolant
Disconnect neg battery cable
Remove altnernator
Remove fuel rail
Remove UIM and TB
Remove 12 bolts from LIM... there are two that will be hidden below the pool of oil in the front driverside and rear passenger side of the LIM. INSIDE of it actually.
Clean surfaces

Read these both to understand why I recommend plugging the coolant ports.
http://www.grandprixforums.net/97-03-na-l36-uim-failure-60667.html
http://www.grandprixforums.net/how-mod-lim-46931.html
I would suggest plugging the coolant ports only. You could open up the end u bend if you wanted.

Replace gasket with some RTV in the corners where the rubber gasket meets the metal gasket.
Use a sealant on your LIM bolts (A teflon based works well)
Torque LIM bolts to 15ft lbs
Put UIM back on and torque to 87 inch lbs watching the plastic as you tighten. If it turns white and starts to break, that bolt is tight enough.
Clean TB with TB cleaner
Reattach TB
Put fuel rail back on
Put alt back on.
Fill and burp cooling system
If you lost water into the engine, drain oil. If not..start and run for a moment , then check the oil. If milky.. change oil.
Click to expand...


Thanks G,

Would the Chiltons manual be handy? I know some of the books have errors in it. Also is there a parts number list to go by?
 


I know they are in the parts list. What I should have said is "OP, don't forget to change the elbows while you are changing the LIM gaskets"

And follow Bills write-up on how to change them out.
 
I just used a set of vicegrips and worked it out when I replaced my UPPER intake manifold. Just smacked it upwards a few times and it popped loose. I wouldn't rock it side to side as it may wallow out the hole in the LIM. As far as the gasket sealer goes, I used the GM grey sealer, but you can use the black stuff as well.

Didn't see injector o-rings mentioned. Might be a good idea to replace them as well.
 


Homey .... Did you read that link on L36 failures? If so..by plugging the ports, you no longer have to worry about the tube or the upper manifold. If you don't plug those ports, I'd suggest buying a new UIM and replacing that pipe, then plugging the ports when the new UIM goes bad in a bunch of years.

Cam...most do. GM LIM's aren't a kit, so they wouldn't. Fel Pro has 6 in there. If you want to do all 12, you need to buy more.
 
BillBoost37 said:
Homey .... Did you read that link on L36 failures? If so..by plugging the ports, you no longer have to worry about the tube or the upper manifold. If you don't plug those ports, I'd suggest buying a new UIM and replacing that pipe, then plugging the ports when the new UIM goes bad in a bunch of years.

Cam...most do. GM LIM's aren't a kit, so they wouldn't. Fel Pro has 6 in there. If you want to do all 12, you need to buy more.
Click to expand...

Thanks G, Heres the UIM Kit I got http://www.ineedparts.com/gm-intake-sure-fix-manifold-kit.html. I see it has 12 O rings, the blue ones. I assume they are the injecter O rings? What are the 6 silver O rings?

Word to your mother
 
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If you are looking for a good video to watch go on youtube and find Brian Manns page and he has a video for the removale of the intakes.
 
Thanks for the help guys, got it about 80% done today. Truly wasn't as bad as I was thinking it would be. Only got the one exhaust pipe to put back on and the idler assembly. Hardest part for me was cleaning up the only manifold and heads. That toke me about 2 hours by its self.


Anyways ill report back tomorrow after I fire her up.
 


Well got it all together and with great anticipation I turned the key and.......bam fired right the fudge up! Smoked a little for the fist hour or so but I let it run while I cleaned up. Now it has zero smoke :) Looking around I see no leaks around the manifold. Looks like a job well done. I'm gonna need a serpentine belt and idle pulley. For the idle pulley, do I need to lock tight that bolt or tq it to spec?

BillBoost37 said:
Did you do HG's?
Click to expand...
Nah
 
Fivefingerdeathpunch said:
Snug works.

And don't forget about that second oil change.
Click to expand...
Yup changed it after I got everything bolted up, plan to change it again in 500ish miles.


One last thing I forgot to ask, I did end up smashing the temp sensor, the one on the bottom of the LIM. I did mange to rig it by beinging the prongs in and electrical taping it on. Gonna order a new one, they just screw on right?
 
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