My 96 z is running hot. I found that the fan only runs when the air is on. With the air off the fan isn't working. What could cause this? The thermostat is fine.

thanks

possible coolant temp sensor .... is the check engine light on??

no, there is no check engine light. I am leaning towards a bad relay in the fuse panel. I will try that.

thanks

Let us know what you found, we are getting a lot of mail on overhating and fans that won't run.

yep, that's exactly what it was....A relay. I went ahead and changed all of them just to make sure. The fan will kick on about 240 sitting still and cut off at 217. I've heard this is how they are programmed. Just FYI.

Thanks for all your help guys/gals...

I would also consider changing it to a 160 degree thermastat. This will make it run much cooler and give better horsepower.

nice car bjames, you have about the same mods as me, the hood and paint job really make it look custom

hi can you tell me where relays located got same fault on my 97 z28 which i imported to uk from chicargo

Yeah wheres it located and is it easy to access I am getting ready to tune up my car tomorrow anyways. My fan only works when the AC is on. :eek:

Before you go crazy hunting for a trouble that may not exist. These cars are factory set to run hot for emission purposes.

The fans will go on whenever the AC is turned on, regardless of temperature. If the AC is turned off, the fan(s) are factory set to turn on this sequence. The primary fan (or both fans at low speed) at 225 deg., and the secondary fan (or both fans at high speed) at 232 deg. Older models turn on fans one at the time, late models turn on both fans toghether and change their speed.

A lower temperature thermostat is of little help, unless the fans turn on sooner to take advantage of earlier opening. However; the car will run cooler ad highway speeds when the air is rammed into the radiator, but will run hot when runnig slow or idling and waiting for the fans to kick in.

With the car idling, the fans should start kicking in when the temp gage is just below the red, and keep the gage from going into the red. Unless it is a very hot day, an idling engine will never get hot enough to turn on the secondary fan or switch ti high speed.

For 1993 cars there is a kit available that will turn the fans on earlier. For 1994 and newer cars the computer has to be reprogrammed.

hi main fan not working only ac fan car had problem while in us guy took thermostat out changed one relay problem fixed (NOT)car overheated on sunday has now done head gasket?running on 7 cylinders blowing water out of radiator and expansion tank,do you know any problems i might come across stripping heads of motor

At least you found the reason for oveheating. Pulling the heads is not much different than any other V8. Just a lot of work. You should get the heads resurfaced as they may have warped. Otherwise there is a chance of blowing the gasket again.

I suspect the gasket was leaking all along, causing the engine to overheat.

thanks planning to pull apart next week will let you know what i find

hi again finally pulled heads just had them back from machine shop they had to take 0.020 off both heads to get them back flat does anyone know of gaskets at sensible price for this car as i was quoted £325 :( which is approx $607 want to get car back on the road

You should be able to purchase a set of head gaskets for less than $100 US from a US supplier. One that comes to mind is Rock Auto. I have had pretty good luck with them.

http://www.rockauto.com/