I have a 91RS with a 305. The fan relay switch was replaced on but I think some wiring was screwed up. I have noticed on this troubleshooting page several questions regarding electric fan problems. I was told that once the temp gauge hits a certain temp it basically inables the gauge from ever reading correctly ever again. Is that true? The car runs great on the highway, but in town with stop/go traffic or just sitting the temp skyrockets! The fan still does not come on at the appropriate temp. However, when I turn on the A/C it comes on. Is this normal? The temp does go down but again if the car is standing still the temp will begin to overheat. I am afraid that since I have been dealing with this problem for over a yearby reverting to the A/C (winter time same thing occurs) that the excessive temp may have caused me to blow a head gasket. The car has 174,000+ miles on it. I love the car and it is clean as can be, no visible oil anywhere!! Everyone comments on how clean the engine is. But I'm worried! If the head gasket is gone, what about getting a new 305 or replace it with a 350? If I get it from GM/Chevy dealer how much are we looking at price wise. I May be able to install myself. Need advice and answers!!

Thought I'd let anyone else who runs across this problem in on my remedy. The fan switch was the culprit! The fan switch is not to be confused with the knock switch. They are both in the same vicinity near the starter cellinoid. They both have a wire running from them. Needless to say, I mistook the knock switch for the fan switch. Once locating the fan switch, disconnect the wire and then with the ignition key on, ground the wire to a suitable location...the electric fan should run. If it does the fan switch is indeed needs to be replaced. If not, then check the relay switch and if not that then check the ECM. Now, two things: the fan does come on but as others have indicated, not until anywhere from abt 220 degrees to say 260 degrees! Is that not to hot?! or was this vehicle designed to run/idle to that level. I worry about any damage that excessive heat may cause, is this a valid concern? Also, I purchased a Haynes manual on the Camaro for models between '82-'92. Lots of good info in this manual but very poor indexing. I could only find one reference to the ECM and did not ever find a reference to the knock switch (which I replaced. The only other alternative that was given to me about the fan situation was to by pass the fan switch and tie it into the ignition resulting in the fan running all the time. Hope this will help someone else down the road. I love my RS!!