1999 Dodge Intrepid

Engine Gases in Cooling System
1999 Dodge Intrepid 6 cyl Front Wheel Drive Automatic 199000 miles

My car began overheating and I had it checked by a mechanic who said exhaust gases were in the cooling system; indicating a likely head gasket leak. I followed the Dodge shop manual closely and tore down the engine myself and took the heads to be presure cleaned/checked and resurfaced. There was evidence on the head and gasket of a leak into the coolant port near a couple of cylinders. I carefull cleaned the block top and didn't see any evidence of cracking. I replaced the head gaskets and intake manifold gaskets, and radiator and waterpump while I was at it. After completing the work, the car still overheats and I had it tested again and the mechanic is still finding exhaust gases in the in the coolant. Is there another test I an do? I'd like to keep the car for my son to drive to school.
July 29, 2010.

I want you to pressure test the cooling system to see if it holds pressure. You can get the pump at most parts stores. They will lend or rent them. Check that and see if the pressure maintains or it drops. If it drops, check everything closely to see if there is anything you can find.

Let me know what you find.


The last thing I did before the head gasket repair was have a mechanic change the thermostat, and the car was still over heating. After I did the head gasket work, and the car was still overheating. The other day I took off the themostat housing to see if there was a blockage and I noticed the thermostat was in backwards! I've since replaced the thermostat, presure tested the cooling system and it runs fine now, with no pressure drop! I also got the NAPA block test kit and I have no engine gases in the cooling system. Everything seems to be okay. The mechanic insist that you can't install the tstat backwards, however I have pictures to prove it. Anyway, thanks for your help and quick reply to my post.

Aug 5, 2010.
He sounds like a heck of a mechanic. There is most certainly a correct and incorrect way to install it. Regardless, I'm glad you got it fixed. Take care and let us know if you have questions in the future.