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Bad gaskets?

R

RichardL12

New member
Hey guys I have a '02 Grand Prix GT which I have noticed is burning coolant. (Low coolant the other day and white smoke coming from the exhaust). What are the possibilities/fixes for this problem? Could it just be the intake/intake gaskets or could it be worse? It doesn't appear that anything is getting in the oil or oil is getting in the antifreeze, and so far there hasn't been any temperature problems
 


Dont wait for coolant to show in the oil, or oil to show in the coolant. If the LIM gaskets have never been changed/upgraded, now would be a good time to do so.
 
QUICKSILVER462 said:
Dont wait for coolant to show in the oil, or oil to show in the coolant. If the LIM gaskets have never been changed/upgraded, now would be a good time to do so.
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Its an '02 with 60K. You think it is the LIM gaskets and not anything worse (head gasket)? Also how long of a job is it to replace those gaskets?
 


Head gaskets rarely go bad on the 3.8. Most likely its the lower intake gaskets and/or Upper Intake Manifold.

I got my revised aluminum lower intake gaskets for $66 at the local Chevy dealer.
 
01GTP said:
You probably need a new upper plenum, the egr pipe likes to melt them and then they start sucking in coolant. I would do that and change the lim gaskets also, for a first time figure a good day of work to do both. Head gaskets rarely blow in the 3800s. ALLDATAdiy.com :: Leading Source of Diagnostic and Repair Information will list step by step instructions and torque specs for your car.
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Listen to this man. I used to have a GT and have worked on several other 3.8's. The upper plenum or lim gaskets is 99% likely to be the cause of your burning coolant. A guy I work with helped his son replace head gaskets on his 3.8 for this same problem. They put it back together and it still burned coolant badly. Turned out to be the plenum around the EGR just like 01GTP described.
 
Go to the how to tab and the top and look for the write up by DuBob. If you are mechanically inclined, you can do it. Make sure to use a torque wrench and follow the proper torque sequence. Yours will be basically the same thing, but you have a plastic plenum instead of a supercharger.
 


That would place me in that category haha. Why can't they be easier to get to? :/.

Oh, and I just checked my coolant, and I don't think there's oil in it, but there's other gross looking poo stuff floating in it. I've already flushed it, and got a lot of the radiatot poo out and changed from dex cool to green/yellow. Would I need to flush it again? Or is the crap floating around in there due to LIM gasket leak?
 
The how to vid is 33 minutes. The actual repair is going to take you the better part of a day if youve never done this before...
 


By upper plenum do you mean upper plenum gasket, or do they typically need an actual new upper plenum? (Mine is supercharged by the way. Does that make any difference?)

Where is the video everyone is referencing, and is there a simple step-by-step write up anywhere for this?
 
if youre supercharged you dont have to worry about replacing the upper plenum, and neither do 04+ n/a guys because the upper plenum isnt a plastic POS.
 
Cool, that makes it easier to swallow I guess.

I found the video--very helpful. Would still be nice to have a full write up that included torque specs and such. I thought I had heard or read somewhere that you had to use new (revised) bolts when re-installing. It would also be nice to have more info on other things I should do while in there--for example, should I do the water pump, timing chain, etc.? I have heard it is a must to do the elbows while in there. Is there anything else to watch out for, or that I should do while in there? How hard is it to port the blower while off? Any other tips or advice would be great. I plan to undertake the operation Saturday.
 
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