Nine11

1992 C2 seems to be always blowing hot air....regardless of the temp setting. Car is now hibernating now but I'd like to start figuring out what needs to be done come spring. Thanks.

Amber Gramps

I may be way off here on the heat system in the '92, but on my '88 and all the pre 964 cars the problem is usually the "flapper boxes" try surching that term. they are just above the transaxle and are the on/off control box for all heat from engine.

Computamedic

The 964 heating system is very different to the pre-89 cars. If the car is constantly blowing hot air it must be because the path the air takes from rear blower to cabin is open - or has a leak.

The most common cause is the destruction of the hot air tubes to the outside of the footwells. Just under the trim, they are little more than compressed cardboard and suffer badly with age. They get holed and leak hot air into the footwell and up under the dash making all the components under there feel really hot to the touch.

If the pipes are OK it's likely to be the failure of on or other of the mixing chamber servo motors. There are 5 servos immediately in front of the scuttle (at the rear of the luggage compartment) and they are well known for failing. Two of them control the mixing chamber flaps and if one or either is stuck open the hot air has an unrestricted path to the dash vents.

It's useful to establish which side the problem occurs. If both sides it's likely both servos are toast.

Hope that helps.

Regards

Dave

Nine11

Thanks for the suggestions and diagnosis. If I recall correctly, the car's left vent, and centre vents all blew hot air. I think the right one did too....but I can't verify that right now. I know if I closed the left vent, the left centre vent blew hot air.

Now, being that the car is summer driven only, I've never used the heat in the car nor do I expect to run heat. But if all servos are toast, what's my budget to be when spring rolls around?

Again, thanks.