I have a 92 Caprice Wagon with a 350tbi that I bought a few months back. The owner before me replaced the radiator, but it still would run hot at times so I went ahead and replaced the water pump and thermostat(fail safe). After that it ran hot once and then the thermostat did what it does and got stuck open. I ran it like that for 2 months with the engine running super cold and rich of course....long story short I replaced the thermostat 5 times now and they all would make my car over heat. But if I took it out the car would run fine but cold since the thermostat would either be missing or stuck open. I’m stumped at this point! Any tips guys?

 

You might have to flush out the engine. There could be a partial blockage.

 

Happened to me before... Replace the fan clutch and you'll be OK.

 

That was my next thing to replace. Never done one before but it doesn’t look to bad

 

Removed the fan clutch and it looks to be new or at least replaced recently. I think the owner before me had this same issue.

 

I guess the temp valve of the 305 has to be 71°C and the 350 has to be about 82°C... If u say that the engine runs cold with valve out..means one thing.. Ur installing a wrong one...and about the fan clutch the inner spring might be malfunctioning.. Consider a new one a give it a try.
i also replaced all of my water hoses (heater and radiator) and flushed the system..that could help for about 30% too.

 

when I said it runs hot, I mean it over heats no matter what with the themostat in. With it out, it runs cold and I just bought a fan clutch. I’ll install it tomorrow

 

pay attention to the fan ! if it's running backwards than that will make it overheat ! also maybe a hose closing up with you when your driving, I had a ford f100 do that once ! also try this ! after you ran the car , shut it down and feel the radiator fins next to the fan, but watch your hands ! if you feel cold spots on the fins than the radiator is clogged in certain places !

 

Yes indeed

 

so the radiator is cold at the bottom but warm/hot on the top.