Just bought a 91 vette - It runs way hot but has not overheated. The temp gauge gets to the danger zone. I have read that this may be a common problem? I have bought an aftermarket temperature control that is supposed to turn the fan on earlier. I need a service manual or wiring diagram. Has anyone had similar situations?

 

1st the obvious, change thermostat, if your fans are operating correctly, could be a restricted radiator.

 

Hi VetteHead, I have a 91 also that had a similar problem. I did the whole thermostat thing but I eventually found a crack in the core and had to replace the entire radiator. That wasnt as bad as I thought, except the first radiator they put in exploded and they had to come tow me and replace it a second time. I haven't had a single issue with temp since then. I would definately try the thermostat first. You can also try a system flush to get rid of any floating corrosion. At any rate...keep her cool...or you run much higher risks doing ring damage.
J - 91 Vette

 

Check for leaks - low coolant level. Id recommend flushing the system. If you have done any work recently, its very possible there is air in the system, or an improper water/coolant ratio, i would go with the first.