d_p_bender

Now that it's winterish in the midwest, the time has come to sort out my heating issues. Here's the deal. My 1988 is equipped with the latest in 1980's Porsche engineering, the automatic heater control. After setting the heat selector to say, 3, the cabin heats appropriately. After a period of time (5-10 minutes), the heat seems to shut down and the cabin cools. Turning the heat selector up a notch or two seems to re-start the process, heating the cabin again and then shutting down. I can play this game a long time, but after a few cycles, I've turned the selector up to it highest settings and experience the same heating and cooling cycle. Eventually, the cabin cools and I'm back to being cold.

Can anything be done to get this to work properly and maintain some constant level of cabin heat? Is this just the price of driving a 20+ year old car in the winter? Will adjusting the potentiometer resolve this issue? Does God exist?

-db

lfe132

Sounds more like a thermostat issue to me. My 84 Carrera is has manual heater controls, automatic-nothing and that's the way i like it.

ron mcatee

Once the automatic thermostat reaches its temperature, the things shuts off. My 88 does the same thing. All I do is crack the drivers window for a short time and it sequences again (I like the fresh air too). I think your sensor is located on the dash behind the windshield wiper arm. It is round and has a couple of small louvers. Make sure the rubber tube is attached as this may affect it also.

Ian Ledger

Sounds like good advice. I will check mine.
Ian

Ed Hughes

One quick tip, make sure you lubricate the air shutters under the car that open and close to regulate the hot air mixture. If one binds, the servo in the control box is strong enough to bend the snot out of the shutters.

theiceman

yeah sounds like the thermostat is reaching temp too soon. it is at the right temp before the rest of the car is.

d_p_bender

Thanks all for the input. It sounds like a thermostat issue, along with being a 20 year old car.

One final question, is the thermostat adjustable in any way?

r911

- Ed -- do you have a special lube to use on these? They pretty hot...

theiceman

not sure .... just put an extention on it and hang it outside the window :-)

Ed Hughes

I can't remember what I used-maybe a skim of anti-seize-but it was for high temp usage. Two or three years later and the car hasn't burned down.

theiceman

if it is for high temp I hear the copper based spray is perfect. That is all I use anyway on the back of my rtors and wheels , and i am pretty sure thsy get hot , even with the way I drive.