i have a 95 z28.
just yesterday i was driving the beast and the check gauges came on so i looked anmd saw that the coolant temp was at the hotst point on the gauge. i immediatly pulled over and looked under the hood and if the car was that hot id assume to see smoke? but it wasnt barely hot it looked normal it was like the gauge was being stupid.
so when i got back in i was cruisin it still read hot then as i was driving it began to drop alot back to normal. then it would go back up and go down. so i fuigure meybe a censor or the thermastat? (if it were the thermostat that would mean that the car wouldnt know when to turn the fan on tho right and it would realy get hot? right?)
so today i drove it all over town parked it got in it drove more its alway at the perfect temp untill about 5 mins ago it got realy hot again!!! so i got out and look under the hood and see the coolant leaking out of the "coolant only" cap and i took the cap off and the tube is loaded with coolant!
the coolant level was NOT that high when i put it in a little while back (meybe it boiled up)
i dont know what the prob is??? now im thinking thermastat??? meybe plz help
if so how do i change it what toolos i need extra parts?? good guides?! ill post a pic if my damn batteries in the camaera will charge!!!!!!![:@]
pictures are uploaded
thanks


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The coolant expands as it heats up. When you replenish the coolant you should add it to the expansion tank, but be sure to check the level with the plastic measuring stick, you don't want to overfill. If you added coolant directly into the radiator, you need to purge the air out of the system, otherwise things will act strangely. You may want to replace the tstat, but be careful not to wet the Optispark. Tstats usually hang in the open position rather than failing to open, so this may not be your problem.
Next time the engine gets hot, verify that the fans are working. The fans are controlled by the PCM based on what it sees from the Engine Coolant Temp sensor, this sensor does not control the temp gauge. The temp gage is controlled by the temp sender unit. So, if the fans don't turn, make sure the fan fuse is OK, check the 3 fan relays, check the fan motors, check the ETC sensor.
There is also the possibility (hopefully not) of a blown head gasket, which also can cause symptoms similiar to what you described. Get a service manual, or subscription to All Data, or if you can go for about $100, get the factory manuals.

 

Did you ever figure out what the problem was?? I have a 95 camaro doing the same thing.

 

it still gets hot every now and then at a stop, but when i go it stops and goes back to normal.]
but i bought a chilton
i flushed radiator
and change thermostat.
do u have a/c?

 

Yes... I have AC. It worked this summer and now ... unfortunatly I have natural AC. The weird thing is... the heater didn't work yesterday morning on my comute to work, worked fine coming home, and worked great this morning (Thank God, cause we got 3" of snow). Now I just wonder if it will work driving home tonight. Also.. I don't have the Z28 car.... just a plain old Camaro. Not sure if that matters or not.
Thanks for the reply!

 

Make sure you have enough coolant and all air purged out of the system. Also, the AC may need recharging.

 

ALSO CHECK THE RADIATOR CAP MINE WENT BAD AND STARTED DOING THE SAME THING IF IT HOLDS 18 LBS OF PRESSURE THEN IT IS GOOD IF NOT THE BUY A NEW ONE BEFORE ANYTHING ELSE. IF NOT THAT THEN THE SECONDARY PART OF THE THERMOSTAT ISN'T OPENING CORRECTLY.

 

another thing if you are overheating turn ur a/c on max it will turn ur high speed cooling fan on and cool ur engine down if u are having a problem then take it to a local dealer or a good speed shop.

 

Dude, sounds like a classic cooling fan problem. I see you posted this on the 11th, if you have not already do so you should get it looked at. This problem can cause serious engine damage if you keep driving it that hot.

 

I agree, but sometimes I get the feeling that some people are more interested in complaining about a problem rather than fixing it.