The Buick That Runs Too Hot

I have a 1995 Buick Regal 3.1. So far, the coolant temperature sensor, ECM and water pump gasket have been replaced. The mechanic says the thermostat’s working fine and the fans are working. No coolant leaks anywhere and the head gasket’s a-ok.

The issue is -the car does fine around town, but after I drive it for awhile and get the engine warmed up, the temperature won’t kick back down. It’ll hover around the 3/4 part on the gauge and creep toward the red zone. It only got to the red zone once, and I’ve been very careful ever since.

I’m getting ready to take it to another mechanic, but want some suggestions before I do so. I’m out of patience and almost out of cash.

Thank you!

A partially restricted radiator can cause this problem. During city driving, enough coolant passes thru the radiator to prevent the engine from overheating. During highway driving, the engine produces more heat and the water pump spins faster to remove this heat. But if the radiator is partially restricted, not enough coolant passes thru the radiator to get rid of this heat. And the engine starts to overheat.


What if the temperature needle goes all over the place? Mine’s jumping around.

Your original post said “it’ll hover around the 3/4 part on the gauge and creep toward the red zone.” Now you say the needle is jumping around. Hover and creep are not the same as “all over the place.”

Which is it?

Just as Tester suggested, a restricted radiator causes problems like this. I had one once, and my truck would sometimes be OK in traffic, other times would run too hot. It always seemed to do OK if I was able to maintain 45 miles an hour, but get stuck at a light, and the temp gauge went up. Same with doing 65 mph or better. The engine worked harder when doing highway speed, and there was not enough flow through the radiator to cool the fluid enough.

Sorry, I should have been more specific. When I was sitting in traffic today, the needle sat at a little less than 1/2. Then it slammed up to 3/4. Then it just started slowly creeping up toward the hot mark. I’ve noticed this once or twice.

Just though I’d throw in my $0.02

What if she had the thermostat temporarliy removed? Then she’d be getting full flow to the radiator at all times, so if she still overheats, it would be most likely a limitation on the radiator’s ability to cool?

(I’m also assuming the “worse at highway speeds” makes it unlikely to be a bad fan.)

NewsLynne, if all else fails and it creeps toward the red zone, you can run the heater to bleed off some heat.

Would a flush clear a clog out or should I bite the bullet and get a new radiator? I’ve never replaced it on this car and I’ve owned it for 5 years. $$$$