Hi,
My little 86 has started demonstrating some new and strange behaviors... From time to time - the A/C Starts blowing warm and at the same time my Temp Gauge starts climbing quickly... It happens at varying times and speeds and seems to last for 10 mins or so then starts to cool down again and A/C Starts blowing cold again... It's happening more and more frequently.

I Suspect that I have a cooling system problem and not an A/C problem since it's ice cold when it works... and perhaps a cut-off switch is turning my compressor off when the temp starts climbing? I am guessing here of course....

In any case - My Educated guess is that My water pump and or thermostat is going out and I should just replace them both.... I just replaced the Serpentine belt and that didn't solve the problem.

Any thoughts? And - do I really want to tackle replacing those two parts myself? Is it difficult? It looks very buried and like i have to remove a lot of brackets and pulleys from other components just to get Access to the Water Pump. I would greatly appreciate any guidance you guys might have on this endeavor.

Cheers Joe

Joe,

As far as the intermittent A/C problem it could be air in the system or an overcharge. What happens is it actually freezes in the lines causing a blockage and intermittent cooling. This could create extra drag on the compressor hence causing extra drag on the engine creating extra heat. Just an idea.

As far as replacing your tstat and water pump I just did it on my 86 and it actually was not too bad. I followed my haynes manual and it was about a 2 hour job and not to complicated. If you need specifics on that let me know.

I'm thinking the A/C problem is a product of the overheating problem.

Make sure the fan is staying ON when the temp starts to rise.
Replace the the T-stat and the radiator cap.
Make sure the rad is properly "packed" or burped.

It is not likely a water pump problem.

sounds suspiciously like a cooling fan relay. This is just inboard and under the master cylinder and a lttle bit forward from it.
That was what wrong with mine when I got it almost 15 years ago. That and no start.

A/C requires air blowing through the condenser to work properly. Sounds like fan problem to me.

Thanks so much and any specifics would be greatly appreciated.

Thanks so much everyone. I do believe that your logic that the A/C is not the problem is valid.... It really does work quite well. It's just that when the Coolant temp starts to climb rapidly - the A/C Compressor Just shuts off and starts blowing humid ambient air.

But now to figure out what is causing the intermittent problem... Hmmm... Not thinking it's the water pump ???

Perhaps either the Fan relay or the T-Stat being most likely?

I do have a manual Fan Switch installed on my Console and I can flip it on at any time and it does always work when turned on... But here is something That i discovered Just This morning...

I started the car this morning for the very first time (so the engine was cold) and I immediately turned on the A/C and Warm Humid air only.... I watched the temp gauge climb about 2 degrees per second and the A/C Stayed off.... A few minutes later it was is if something just released and Suddenly the Coolant temp started to drop (it had reached 200 degrees in just a matter of minutes) and the A/C Started working again.... I drove for an hour on a little road trip into the country and problem did not reappear... UNTIL i stopped and turned off the car and got out for a while... then started it up again and the same thing happened all over again. I drove home and she was fine... This is just a weird problem

Does this bring to mind any new thoughts?

Thanks again everyone You are all terrific!!

Joe

T-stat

Thanks so much Guys.
I did replace my T-Stat this past weekend and Now I will wait and see...

I'll let you know

Cheers ~ Joe

After you replaced the thermostat, did you let the car idle until it openned and then topped off the coolent?