Cooling system problem?

jabGT

New Member
Mar 11, 2004
59
0
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Michigan
I am looking for some advice before I pull the heads to change head gaskets?

I am getting bubbles in overflow, but it won't happen when car sits and idles from a "cold" start until 15-20min, just after driving it a short distance, taking it easy or driving hard doesn't make a difference(supercharger off car). I have tried burping the system multiple times, but when I open the cap when idling (engine not hot yet) the coolant will just overflow the radiator neck. After a drive, radiator cap(new cap) is hissing and if I crack it slightly the overflow will bubble like crazy, big bubbles and small bubbles but no "foam". Pulled all plugs no sign of coolant nor can I smell or see burning coolant in exhaust and no coolant/oil mixture. Coolant does have alot small gray specs in it, but I assume thats from the last time a had the heads off. There is a slight iridescent film on top of coolant. Car does run slightly hot when idling 210 -autometer gauge, M on NORMAL on stock gauge, but while driving temps go down to 190-195. Upper radiator hose rock hard after shutdown, squeezing it while thermostat is open I can feel bubbles cavitating through it.

Is it possible that from opening and closing rad. cap so much that I am getting to much air into the system and not allowing it to burp itself?

I did have cooling leaking out the timing cover gasket when I pressure tested the cooling system(lost 1-2 psi over 15 mins) could this have anything to do with it?

Could a have a clogged radiator?

When I open the cap would it cause the coolant to boil (if coolant was in bad shape) because of reduced pressure?

Any other ideas or opinions would be appreciated, I would hate to swap out head gasket just to have the same problem.

Sorry about the long post?

Thanks