I have a 96 3.8. Runs and rives great, only problem now is when I leave it running and I'm sitting say for example in a traffic jam then the temp. gage starts to heat up and when I start to go Im smokin when I take off. The car sucks water and anti freeze pretty quick IMO but there is no oil and water mixing. Could it be a head gasket or thermostat? And somebody told me if I do a compression check it could hurt the gasket even more if that was the problem

 

Drives^**

 

sounds more like a lower intake gasket (the 3800 is notorious for blowing them) anyways id pull your plugs and see if any of them look brand new (when coolant gets into the combustion chamber it vaporizes and causes a steam cleaning of that cylinder) then if thats the case and your going to fix this yourself pull the intake and check the gaskets out (you gotta pull it off to get at the heads anyways)


also instead of posting edits just hit the orange edit button in the bottom right corner of the post

 

Okay appreciate the reply and hint

 

Compression test will not hurt the car. Since you are just using the starters torque to create pressure it is low, much lower then the pressure your headgaskets see at idle. You want to look for variation in compression. Also if one or more of the plugs are real clean that would indicate a issue as the coolant tends to wash the cylinder.

You might want to think about a coolant pressure test, the testers can be borrowed from autozone or other chain parts stores and you can hit up youtube for a how to video.

Normally when the 3.8 lower intake leaks it leaks either to the outside of the block and ends up on the ground or into the oil, it is possible to leak into the cylinders but it is pretty rare.