Thread: coolant in the exhaust???

ok.. heres the story... 99 gp gt 170,000 miles just did a head gasket.. while i was in there i did all the intake gaskets, had the heads and lim prof. cleaned.. new plugs and wires, still wasnt running right.. so i did the map sensor too (coolant actually completely separated the sensor) and i did the pcv valve.. that solved the problem.. but now i have fluctuation in my rpms again, not as drastic as before but by a couple hundred rpms at idle. and when it has been running for a while then there is a smell of burning coolant when i have the heater on. and the low coolant light occasionally comes on but goes off after a max of like 2 minutes.. im probably gonna get a million possibilities for what is wrong with it, but hey its worth a shot

Does your windsheild fog up at all around the defrost vents? Is the carpet near the heater box wet? This could be the heater core starting to go. If you lay on the floor at look at the black airbox that covers the heatercore with a flashlight look for trails of dried up coolant.

Get it up to operating temp and pop the hood and check ALL the hoses. Especially the 2 heater hoses. One may be leaking.

On the RPM issue, I would check for vacuum leaks since you disturbed so much of the engine. With that amount of age/mileage it would be a likely candidate. Check the vac. lines that connect to the TB. Mine was cracked there. Also be sure your PCV valve has 2 orings and the cap is on tight. The PCV should have 1 o-ring around the base of the actual valve itself and then a larger one that sits in the UIM right under the cap that the MAP attached to. I believe it should also have a spring on top of the PCV valve as well.

check the heater lines running from behind the alternator to the center of the firewall, as they are right overtop of the exhaust pipe and manifold, which could be the cause of burning coolant.

as stated above, check vacuum lines for the rpm surge, very common issue. there should be a diagram on the underside of the hood near the latch.

i had the same problem on my truck a while ago after replacing a blown head gasket. long story short my heads where slightly warped and needed to get them machined cause it wasn't sealing right.

Since you did the head gaskets, did you use NEW bolts? The stock ones are TTY and cannot be reused.