New to the group I just bought a 92 25th anniversary camaro with a stock 305 the guy I got it from said it only overheats if I change the ac/heater controls from bi level I've been driving it for 2 weeks now and it has yet to overheat but I also haven't moved the controls due to being scared it will over heat I did notice he had the a.c. compressor is disconnected has any one ever had this problem or know we're to start to diagnose what the problem could be ?

 

I'd venture a guess that the temperature sensor that kicks on the cooling fan is defective.
Probably selecting either of the air conditioning modes (max, normal, or bi-level) will keep the fan running and prevent the overheating.
You need to fix the faulty sensor or wiring that kicks the fan on based on coolant temperature. I can't be more specific than that, not knowing the fan logic on a '92.

 

I would start by seeing if it actually over heats. Turn it off and see if it starts to go over the temp the needle usually stays at when it is on. If it starts going over that, then turn it back on and see if the temperature starts going down. If so, then you have one or more problems.

 

Yeah, most likely the fan switch is the problem. A search will provide you with
testing info and various solutions. Need any help with that?

 

I had the same car and it ended up being the fan switch on the side of the head. It's a temperature operated mechanical switch than closes when a certain temp is reached, activating the fan. Since it's heat and mechanically operated it's prone to failure

What you need to do is turn off the blower and see if it overheats. If it starts climbing, look under the hood really quick to see if the fan is on when it's hot.

If not, you know it's the fan not working, now you have to figure out why. Fan switch, fuse, relay, etc.

If the fan works and it's still overheating, you have other issues. Internal/external leak, clogged radiator, failed water pump, etc

Figure out which of these is the case then report back

 

That makes no sense at all.

Bi-level is just, AC out of both the dash and the floor vents. No different, as far as what goes on under the hood, from any of the other settings that use the AC; which are, AC, max AC, & defrost. The only settings that don't use the AC are Off, vent, & heat.

Personally I think the PO is merely full of canal water. I'd be inclined to put away the "scared" and just use the car normally. And of course, hook the AC back up.

 

Technically speaking, the blower removes heat from the cooling system, and bi-level operation would allow for more volume of air to flow through if the blower could adequately output. Sounds possible so I wouldn't discredit that claim entirely.

AC has nothing to do with this problem, but if he hooks it back up and uses it, it may cause the car to overheat.

Only one way to find out!

 

 

Since his car has a single fan it is actuated by either the fan switch or AC on.
Since it works with AC on, the fan and relay are good. That pretty much points to fan switch failure or problem with the green/ white stripe wire to the relay, or the fan switch connector

 

I doubt he has a problem at all, beyond just a PO's overactive diarrhea of the mouth.