Vandit

I just picked up my '91 C2 yesterday and proceeded to drive it all 650 miles back home. I owe you all a introduction/picture thread.

When I got home, I noticed alot of heat in the pass. footwell and glovebox area. I was running the A/C all the way home.

This morning, I noticed a little bit of hot air coming out of the dash vents even tho I did not have the blower running and the thermostat is set to the coldest.

Any ideas? Is it related? Thank you.

jimq

your paper heat tubes behind the lower side panel is probably ripped. Pull the panel off and check it.
Oh yea welcome

ThomasC2

+1, the hose is broken.

tbennett017

IF it turns out your hoses are okay, then the next thing to check is the condition of the heater servos. Do a search here and you will find loads of information. There are four of them, two on each side. one controls hot/cold, and the other controls up (defrost) or down (heat).

ThomasC2

A small, small hole/crack in the hose is enough. So have the engine running and feel around with your hand even if you can't see anything at a first glance.

Thomas

naidoo2610

Same issue here. Here are the part numbers for the hot air hoses. different part numbers for left and right. I replaced both - ~$25.
96457252801
96457252701
I guess the way the system works is by creating a vacuum which closes the heat exchanger flap and the smallest tear will break the vacuum and open up the flap. Other issues I found through research were sticky heat exchanger flaps or servos that were stuck.

Vandit

What was involved in unsticking/repairing the flaps/servos? Any necessary replacement parts there?

Rocket Rob

If you are lucky, you can open your servos and clean then. I had two stuck servos and was able to repair one. I had to buy a replacement for the second. See

http://porsche964.co.uk/technical/servos.htm

naidoo2610

not sure if you need any parts for the flap. I also printed the servo instructions from the site Rob submitted above but didn't need it because the paper hoses solved my problem

Gregg-K

When I had this problem, it was due to the heater duct hose having become detached from the HVAC plenum behind the glove box. Simply had to push the duct hose back onto the plenum, and tighten the clamp.

.. Gregg

Vandit

Do ya think this crack in the hose is big enough to cause a problem?



lol

I need to put together a nice big order of random odds and ends, including the pass. side heater tube, stat.


For those of you who have replaced these, how involved/difficult is it to replace/attach the other end of the hose? Where is it attached to?

Marc Bixen

That's definitely a large enough tear. It's not hard to replace the hose, but be careful not to break the plastic nozzle. It connects with the A/C- Heater housing in the trunk. Sort of a bulkhead fitting through the firewall. The nozzle from below is slips into the upper housing and is held in place with 2 one way tabs molded into the nozzle. This gets brittle over time and has a tendency to crack. There's also a foam seal between the nozzle and the firewall. I recommend cutting the old hose to make it easier to remove.

Gregg-K

I think you just found your problem!

It's easy to replace: undo the big hose clamps at either end, collapse it and pull it out. The top end attaches to the HVAC plenum, the bottom end attaches to the tunnel that runs along the rocker panel area.

Extend the new hose a bit when you get it, but refrain from doing too much until you get it into place. Then, gently extend it when you get it into place ... first attach the bottom end, and bend the upper end carefully to get it aligned with the port on the HVAC plenum.

.. Gregg

Vandit

Which # is for the right side (LHD pass. side)?

Thanks!

Rocket Rob

96457252801 = Right side
96457252701 = Left side