Out of the blue, I'm overheating.  The heater is working fine and blowing hot air (I'm told this is an indication the water pump is probably ok).

Any ideas where to start to trouble-shoot the overheating problem ??   Oh, and I don't recall hearing the fans on (I'll check this tomorrow) so I'm wondering if it may be as simple as replacing the fan switch. 

Any help here greatly appreciated.

Many thanks

Views: 640

Reply to This

Replies to This Discussion

Cool! (pun intended) I am glad to hear everything is working!
Glad to have helped!
From my very limited experience, I've found that it could be a couple of things including the fan switch, the thermostat or even air in the coolant system (needs bleeding). You might also want to check belt tension or for blockages other than air.

Good luck!

I'm glad you got your overheating problem resolved. I just got my AC fixed, and I've noticed that when I turn the AC on, the engine seems to run hotter. I haven't checked to confirm the fans are coming on; I'll do that today. Any thoughts on the AC/engine temp connection? I didn't notice this before. The car isn't overheating, but the temp gauge needle got close to the 10:00 o'clock line soon after turning the AC on, and it wasn't a terribly hot day (mid 80's). The car has a new thermostat and radiator cap, and a recent oil analysis revealed not a trace of glycol in the oil, so I'm assuming the head gasket is OK.

Also, I have a question about the theory that blowing warm air through the vents indicates the water pump is OK. Mine blows hot air just fine, and I replaced the pump at the last belt change, but I'm not quite getting the connection between warm air coming from the vents and a healthy water pump. Thanks in advance.
I can tell you that when I put on my AC, my engine temp went down. For sure it did NOT go up.

As to the water pump... my car heats up very quickly (I assume all 968's do). My thoughts are that if you have the heat turned up all the way and the fan on high, you are extracting heat from the cooling fluid. If your water pump is ng, then you should expect a drop in heating temp from the vents.

Not sure I've answered your questions though. If not, please write back and I'll try again.

Interestingly, my engine temp goes down with the AC on, too. I do not understand that, to be honest. In fact, the temp remains stable just below the lower line on the temperature gauge.


I think what happens is that when you put on the AC, the fans kick in because you're putting additional load on the engine. When that happens you introduce additional cooling into the system and the temp of the coolant reacts accordingly.

When I was having my overheating problems I put the AC on knowing it would engage the fans. Seemed to help.

That makes a LOT of sense. I'm driving around with the A/C on all the time, now. Mainly because you can heat the car or cool it depending on the conditions, and I don't seem to have to worry about overheating at all.

Thanks for the follow-up.

me as well, my fans do kick on at the 10 O'clock position but if I hit the AC before that it keeps the car cool and the fans on. Porsche list 3 different temps for both the fan switch and the thermostats in the parts catalog. The 180 degree is listed as the stock temp with one higher temp and one lower temp switch . You can use them in conjunction with the different temperature set thermostat for the water. In Alaska I just keep the stock as I drive it mostly in the Summer but have taken it out many times after the snow has been beat down to Ice .


Support Our Ad Partners

© 2023   Created by Ray Starbird.   Powered by

Badges  |  Report an Issue  |  Terms of Service