I have a 97 Chevy Venture that was overheating. I had tried a few things (new thermostat, coolant refill, bled air from coolant system) so I took it to a mechanic. He told me that there were exhaust fumes getting into the cooling system and that I needed to replace the head gaskets. Unfortunately, when I took the heads off I did not see any obvious problems with the gasket. I did find that the water returns in the heads were about 50% clogged with sludge (could be from radiator stop-leak that I used a few months ago). I am now worried that the gasket may not be the problem. What should I do now? Do I put it all back together with new gaskets and hope for the best? Is there anything else I can look for?
Thanks in advance,
-Stephen Smith