Porsche Enthusiasts Club Forum

Hi all my 1989 944 has just developed a temperature problem, the heater will go from very hot to cold then back again. It does not matter if the heater is on 32 or less also if the fan is on or not. Not sure if it a thermostat problem or something else. Any ideas On the problem or guidance would appreciated.

Probably a broken heater clip. Maybe a vacuum fault. A search for heater clip will tell you how to check it.

I wonder actually if your cooling system needs bleeding. Any guesses anyone?

Hi guys thanks for the advice I shall check it out.

Be aware 944s are a real pain to bleed, get the front nearside up as high as possible and have the heater on.

Oh and use the bleed screw on the head, one guy says he bled his but didnt know about the bleed screw, so I've no idea how he did it.

He blew the head gasket the following day!

I had this happen on my old 86 Lux . I also used to hear water gurgling noises when I was driving along. It turned out to be the head gasket leaking. Hot combustion gas pressurizing the coolant system
Have you noticed the coolant header tank level being higher after a run and then a lower level when cold ?
Also look for white smoke and water from the exhaust.
Hope its just air in the system.

And be careful not to over-torque the bleed screw. They are hollow and therefore fragile!

Mechanics who are old-skool enough, know how to bleed a system by squeezing pipes in a certain way with the expansion tank lid off.

With due respect to "experienced " mechanics squeezing pipes is no substitute for using the bleed screw on a 944. The system is far more complicated than an A35, upon which the pipe squeezing method does work to my knowledge!

Hi Gary,

What does the temperature guage do?

Does it remain constant or does it rise and fall at the same time as the heater temp?

The temperature gauge stays constant, it is just the in car temperature varies.

Sounds like it might be worth checking the Clarks Garage site for info on the heater system.

I'm not at all familiar with the later models, but there is a fair bit of info on the Clarks site suggesting either sensor faults or cable adjustment.

Good Luck.

Jeff