ttwirz

I put a new fan switch in with a lower temp and had the same problem. Basically the the engine would not get hot enough to open the thermostat and generate heat. If I stopped at a light it would start blowing warm air. Car ran great all summer but once the outside temps dropped a bit my temp gauge would sit right below the first line. That all said, is you car getting up to temp?

Tenacious_G

Yes, the car does get to temp, it's comfy around the 9 o'clock position although depending on how hard and long I'm driving it will creep closer to the second white bar, just before the red. When I first bought the car I had overheating issues with the engine, and replaced the fan switch and the thermostat like you did. But it's stayed happy since...

bluedevil

My heater was out and when I went to the shop they noticed the vac lines behind the motor were either cloged or not connected. Once they had that all hooked back up the heater came back to life. Have you done any work up by the firewall? Also if the vacume control is old that may have gone out as well, it is a 10.00 dolar part and easy to instal. May not be the problem but worth looking at.

Tenacious_G

I've only checked the lines to make sure they're still connected -- if the vacuum control is busted, would that mean no air at all was coming out, or just no hot air?

I think Fishey is going to help me look over stuff for a bit after he gets out of class, so we'll check that, too!

Fishey

Just looked at Andrew's car and found that he had vacuum at the supply line to the HVAC unit but none at the Vacuum line for heating valve. I am guessing the problem lies somewhere in vacuum lines or maybe Solenoid valve for heating (we didn't have the tools to go any further) but thought I give everyone the update as I am not all to fresh on common issues with the unit.

Tenacious_G

Thanks again, Ron!

Tenacious_G

Okay, so this weekend I was back in Cincinnati and found a couple new things out --

-Timing belt noise hitting against the belt cover -- gone. Maybe I was on methamphetamines the day I heard that, can't be too careful. So I'll mark it under the "things to watch for in the un(likely) event they resurface" checklist for the car.

-As it turns out, not only do I not have heat, but I don't have Recycled Air or AC, Andy thinks it could be the climate control head on the fritz, so as soon as I can borrow someone's that's working (probably one of his :-) ) I'll be able to test that theory out... Until then, I'll just drive when it's sunny out and things will be fine :-).

On a sadder note, some ******* put a dent on the roof of my car, just forward of the sunroof on the passenger side... Gah.

Mello

I can't figure out my heat problem either. I haven't had heat since I bought the car 6 months ago. The heater valve is fine; opens and closes. The two clips are attached, and both arms move when they're supposed to.

There's an insulated pipe in the passengers foot well. That for the hot coolant to come in, right? If so, it doesn't feel hot. Could there be air in the coolant system by the heater? I did a quick bleed, and didnt seem to get any air.
I don't get the slightest tad of warm air ever. I'm not sure, but I think I removed the heater clip and didnt get any hot air then either.

Rip It

Air in the coolant will cause this problem. I just recently changed pumps and had to rent a radiator pressure tester to get all the air out, as per Clarks' garage. Also the coolant heater valve requires vaccum to close not open. Good luck.

Mello

Still no heat! I'm almost sure coolant isnt getting to the heater. Everything else seems to check out. The insulated pipes coming through the firewall dont feel hot at all. I jacked up the car to try to get air out but that didnt do anything. I used a smaller jack that goes up about 18" Maybe I need to jack it up even higher? The thing is, I've drained other 944s and refilled them without a problem. I don't get it.

CurlyDE

Just thought I would pipe in with my no heat problem. I have not had a chance to look at it ... I do not drive the car often right now. Anyway, this morning the heat was super hot and working too well. I turned the climate control temp **** down a little bit (about 1/3 of the way) and it was ice cold then. Turning the **** back to full hot did not adjust the temperature back warmer. I played with the temperature **** (going from cold to hot) periodically while driving to work, but it never got warm again.