Mattkovitch

My car is a 91 305 with a tbi. the car heats up to normal operating range and stays there just fine; unless, its idling for any period of time. if im stopped for too long the temp will start to rise. I was at an toll and the line was held up for a little bit and i had cars infront and behind me and had no where to go and almost over heated, im afriad to drive on the highway because if i hit traffic then its gonna over heat. but as soon as i get going and get some air flow to it then it cools right down to the normal temp. any ideas?

BOTTLEDZ28

iTrader: (9)

What was the temp at? These cars were designed to run hot. 200-220 degrees isnt overheating according to GM.

Mattkovitch

It's over heated once.(past 260) and my car stays at about 180+ and when it gets to 220 it doesn't show any signs of stopping. I'm thinking the fan might not being going on but I know it was working for a fact at least a few weeks ago so I don't think that's it because it's been doing it longer than that.

sofakingdom

iTrader: (1)

The fan comes on at around 235.

Doesn't sound like your car is overheating.

Mattkovitch

I hope you're right. Maybe I'm just paranoid because of one time it did over heat from a coolant leak. I'll let it idle in my drive way after driving and let it heat up and see if it'll kick on. Thanks

Fabrik_8

That actually sounds like you are low on coolant. Air is going through the radiator while your driving causing you temp to cool down, and poor circulation at idle. Im not too sure but it makes sense to me any way lol

Ron U.S.M.C.

Burp the air from the coolant.
Start the car with the radiator cap off and let it idle. Its best if the nose of the car is little higher than the rear because the air will want to go to the highest spot.
When you can see the coolant start to move in the radiator very gently squeeze the top hose like your pumping it.

Do that every once and a while. If at any point you see air bubbles at the radiator fill hole than its doing its job.

Watch the coolant level as you go and add some if you have to.

I fixed my fans to come one at an earlier temperature with a 180* thermostat.
My car stays in the 180* to 190* range even in traffic.

Mattkovitch

Thanks I'll try that too. What thermostat is on these cars? Mine stays at about 180 maybe a little more at any driving speed