So I'm driving to work yesterday and while accelerating I hear some pinging. I look at the gauges and the engine is HOT. I pull over open the hood and coolant is boiling out of the rad cap. I get back in and the temp has gone down about 20 degrees. I drive the rest of the way to work with the temp at about 220.

At work I top off the rad with water let it idle for 15 mins and it gets a little warmer than usual but stays at about 180ish. Drive home and it slowly gets up to about 220 again on the highway so when I get of the highway I stop in a parking lot and let it cool for about 10 mins then get on the road again. A few miles from home I catch a stop light and oddly enough notice that while at idle the temp starts to go down but regular driving on streets causes the temp to go up. So anytime that I am moving it gets hot but at idle it seems to cool down.

My first thought is the t-stat. The rad was a little low when it first overheated, or it was when I was able to check it after it cooled, so I was wondering if air could be caught in the motor. IDK, any help will be appreciated. Oh and for the record stock clutch fan, 305. This car has never overheated before.

-* Edit - I guess this should maybe be in cooling. If someone thinks it should please move it.

 

Have you checked you timing? You mentioned you had pinging and pinging is often times the result of over advanced timing as well as overheating. Now when u say you looked down and it was HOT how hot are we talkin? Overheating can cause pinging too. Have you checked the usual is the air dam in place and you dont have any leaks?

 

It sounds like you have a restriction. Have you checked your lower radiator hose. It has the tendency to collapse. Some people put a spring in it, but over a dozen years or so, that can probably deteriorate.

That would be my first guess. The lower rad hose collapsing under throttle. The second guess would be a partially clogged t-stat. as that is another bottleneck.

 

Could be any number of things causing it to overheat including a cracked head or a bad head gasket. The cooling system could be fine.

The only way to know is to have it properly diagnosed for the cause of the problem. Many times it's just a simple stuck closed thermostat however if you say the temperature comes back down at an idle, I'd rule out the thermostat.

 

 

Camaro or Firebird? Big difference in the incoming air.

Is your airdam still under the car?

 

Check the air dam.

 

check in front of radiator for obstructions. how long has it been since radiator has been flushed? could be the clutch fan also,jimmy