Hey Guys,

Having troubles again with the 74 Dart. This is Thor's old awesome Dart that I bought with the core plug leak. Got that taken care of and thanks for all the great advice.

About 2 months ago the engine was overheating and blowing off steam through the radiator overflow tube. I ended up replacing the radiator and everything was OK. But now I'm back to blowing off steam again after about 5 minutes of driving.

Can't figure out what's going on. The water pump isn't leaking through the weep hole and I think possibly Thor put a new one on before I bought it. I replaced the thermostat and actually took it out last night to check to make sure it was not a bad one.

All that's left is the heater core?? Or am I missing something?? Should I try bypassing it just to check? Dang I don't want to replace that too, I've heard it's just easier to junk the car if you have a bad heater core.

Sorry for more ignorant questions that I'm sure may be answered somewhere else already. Just gotta get this figured out this weekend.

Many thanks in advance,
--M

Weak radiator cap maybe?

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Thanks Mike

Here are some things I'd check. See if the radiator is uniformly warm-no cold spots-she may be passing crub that has blocked off your new radiator. Is the thermostat installed correctly and is it working-that would be an easy fix. Make sure you have a good flow -and no bubbles in the radiator after the thermostat opens and that you have no kinked or blocked hoses. Just some things to try. After that I'd check timing to make sure that hasn't moved-but I don't think that is your problem.

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Good gun control is hitting your target repeatedly

Yup, I'm also voting for a blockage in the system, either rust and crud from the block now plugging the radiator or a stuck thermostat.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

Hey Guys,

Thanks for the quick responses. I'll go through all of the hoses and see if there's a clog somewhere. I did the hot water test on the thermostat and it seems to open OK. That and we ran it without a thermostat and still had the same blowoff problem.
Perhaps another flush & fill. Dang this car is killing me on radiator fluid!