Questions and Answers
Overheated Camero
Q. I have a 1992 Camaro w/ a 305 V8. My fan will not turn on (I believe it's electric) when the temp gets high. However, it will turn on if I turn on the heat or the A/C. Is it some kind of switch or sensor that is bad?
Also, before I realized what was wrong, the coolant did boil over - will this have any long term effects on the coolant or will it be OK?
Thanks,
ChadA. Okay, this is an easy one. The cooling fan sensor in the thermostat housing is bad. That grounds the cooling fan circuit to turn the fan on at a certain temperature. When you turn the A/C on, it grounds the circuit through the main A/C relay. That, in effect, is telling you the fan and wiring is okay and that the grounding sensor is bad.
It is very easy to test, just unplug the sensor and ground the end to the block. The fan should come on. Once you confirmed this, just replace the sensor and you've fixed it.
As far as the coolant boiling over it shouldn't effect the coolant. I say shouldn't because there is two schools of thought about this question. You can get an anti-freeze hydrometer at an auto parts store and test it. Get a decent one, the ones with the little balls can be unreliable and very difficult to read.
If you haven't replaced the coolant in a couple of years, now would be a good time to do it. It's due for a change and new coolant will eliminate any questions about the quality of the coolant.

