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2004 Grand Prix white smoke exhaust

S

schorkwa

New member
I recently replaced head gaskets, lower intake gaskets, and upper intake gasket due to losing a gallon of coolant a week. I'm not losing any more coolant but now have white smoke coming out of the tailpipe after the engine warms up, approx 10 minutes. I did not have white smoke coming out before I did the job, but now I do. What did I do wrong? The upper intake is aluminum, not plastic. The head gaskets and lower intake gaskets are not metal, could that be it? I had some rubber o-rings left over after the job as I couldn't figure out where they went, upper manifold maybe? Are the LIM bolts supposed to have thread sealant and o-rings on them? Please help!
 


With white smoke...that means the car is eating coolant. Don't start it again until you go through everything. You also didn't need to replace head gaskets...99.99% of the time its just the intake gaskets that are sh1tty and rotten from the plastic factory junk.

Find the leak or the non-sealed gasket...and change your oil before starting it again. Hopefully you didn't damage anything.
 
The fact that it goes away after 10 means is why my guess is it is condensation "smoke" and it has always been there and you just never noticed it.
 
Actually, it doesn't start the white smoke after initial startup. It takes about 10 minutes and then it stays, once the engine is warmed up.
 


unless your talking crop dusting white smoke. then you got a issue. if its just a little out the tail pipe id not worry.
 
Get down on your knees and smell the exhaust. Does it smell normal, slightly sweet, coolant, etc... Hold your hand on the outlet and see if there is only water on it. A new rebuild will smoke a little at first too.
 
O.k. I took it apart again and replaced the LIM gaskets with metal ones and sealed the bolts. However, I still have crop dusting smoke coming out of the tailpipe! It's been about a week and it's still coming out. How long can coolant stick around in the cat? Should I try draining it? If my UIM is aluminum would it help if I plugged the 2 coolant holes coming out of the LIM to the throttle body? Or does that only apply if the UIM is plastic? Any help would be greatly appreciated.
 


a gallon of coolant a week would result in lots of coolant in the exhaust system, more than enough to reduce the cat/O2 life.

if the smoke comes as soon as the hoses get hard (coolant is under presure) then you may still have a problem, the plastic uim loves to leak small amounts of coolant through the egr plastic erosion issue. you may have a small hole that doesnt really leak till hot.

remove the radiator cap/leave the system open while letting it warm up/get hot, if smoking is gone/reduced, ppressure test with the TB off and look for coolant to leak down through the egr stovepipe
 
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