so lately my car has been jumping right up to about 260+ on my heat gauge within a mile of driving it. so i thought hey it could be the water pump and thermostat. i replaced them both and when i took it out for a spin it would stay fine temp as long as i was driving but when i stopped for over 1 minute my heat would rise and would periodically shoot my coolant cap off. im thinking it could be the head gasket because the car is also having sweet smelling exhaust and steam coming from overflow along with fast radiator draining. so if you guys have any other ideas on what could be wrong let me know please.

 

Sounds like a head gasket. Are both fans running when it overheats? You might want to have a shop pressure test the cooling system.

 

no the fans arent running but they never have and now its having a problem i think i just need a new relay for the fans though seems like it gets way to hot for fans to help regardless

 

one other thought; there are two plastic mold pieces that goes under the car which helps it collect air while the car is moving if its bent, out of place, or missing that could cause the car to overheat as well

 

I agree with jv9999. Head gasket. Does the engine run bad at all? Is there white smoke coming out of the exhaust? When you take off the cap, does it smell like exhaust inside the radiator? When the engine is completely cold, start it up and try squeezing the upper radiator hose and see if there's instant pressure. If there's a blown head gasket there's a chance it could pressurize the cooling system. Could be your answer for your cap blowing off.

 

no engine isnt running bad or anything. but i think that air collector is bent

 

re positioned the air collector but it over heats when its running and just sitting in park. so that really isnt what im worried about right now. ganna go check if the radiator is plugged doesnt seem like my car is getting proper circulation but i dont know what the cause is

 

I would look into the fans not running-when your moving, a decent amount of air is flowing across your radiator, but at a stop your fans are supposed to pick up the slack. If your at the top of your temp gauge with no fans running then that seems like the issue. also turning your a/c on should turn one of the fans on, if they arent running already-try that and if you still get nothing, start searching for your fan problem.

 

im having the same problem with my 86 z28, if im driving its fine but if it idles for anyamout of time it overheats, ill look into that fan issue to.

 

lol checked to see if fans work they do but there not coming on when the car is getting hot and i replaced both fan relays. cant get the danm things to turn on might have to run the fan to a toggle

 

Since one of them is turned on by the ECM, it makes we wonder what your ECM thinks the engine temp is. Do you have a scanner? The other relay is connected to a switch in the passenger side head. The wires have a habit of falling off. That fan comes on pretty late though. Something like 234F.

 

do you have a name or part # to the piece you posted in this picture? i need this piece ASAP...