OK. Here's the deal. I started my car this morning and ran it on fast idle for no more than two minutes with the sole intent on checking the coolant in the radiator. After shuting it off, I checked the fluid and it was fizzing! http://www.chevelles.com/forum/redface.gif No, not boiling. It looked like Alka-Seltzer in my radiator, but it had the consistancy of the head on a freshly poured beer (which, by the way, sounds pretty good right now!). The coolant wasn't hot at all to the touch. I've already checked my spark plugs and everything looks fine. Compression tests find nothing wrong, so I know its not the head gasket. Is it possible that one of my heads is cracked? I don't know what else it could be. I've ruled out the radiator cap, external pressure differences, and I'm pretty sure its not the head gasket (unless the compression tests lied to me). BTW, 72 Chevelle 350/350TH 4bbl. factory air. PLEASE HELP!!!

Hey, did you check the oil? Make sure there isnt any water in the oil and also vise versa. By the way, you havent put any sort of radiator additive in it lately have you? That might cause something like this. Good luck man.

----Jerry----

Thnx for the response, Jerry. No additives, no oil in radiator and no water in oil. Now what??? I was thinking about just flushing the crap out of the cooling system and going from there. Any help will be greatly appreciated.

72,
Compression tests will not always show a small head gasket leak. It may be worth your while to find a shop with a tester to check for combustion gas in the radiator. Most up to date shops have exhaust gas analyzers and they can be used to do the test. It would probably be worth a few bucks to be sure, could save a lot of work and time.

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Bill Koustenis
Advanced Automotive Machine
Waldorf Md

1971 Heavy Chevy - original owner
Team Chevelle #100

Flushing the system might not be a bad idea. Bill also has a valid point. It never hurts to make sure there isn't a leak. I'll keep thinking about other possible causes. Please email me or post another reply when you figure it out.

----Jerry----

How old is the coolant?

First of all, thanks for the help. Coolant was changed December 1998 along with entire system flush. I played with this weekend and I'm still stumped. If there is a leak somewhere, its pretty small. No white smoke in exhaust, etc. I'll keep tinkering with it and I keep you up-to-date on what I find. Thanks agian.