With the heater off, the vents put out significantly warmer air than the outside air, even after I drive for awhile so it's not just the residual heat in the "lines".

I assume it is a flap that isn't closing (or opening) fully. Can someone tell me where to start?

Thanks!
--
1993 240 Classic; 1993 945 Turbo; 1992 944 Turbo; 1997 850 GLT

I have this problem to (same year model)
In my case it's the Heater Control Valve that is not closing all the way b/c of its being 17 years old. Step one is to see if the cable attached to the hot cold slider hasn't slipped. The ends of the cable housing need to be firmly attached so that the cable goes through the proper range of motion. access it from the drivers side, removing the side panel of the center console.

If that doesn't fix it, then the HCV need replacing. (true in my case) ~40 -50 dollar part and not too easy to get to, but it's been done.

The poor man's fix is to put it on recirc and use the windows for ventilation until you actually want the heat. This is what I do for now.

Happy wrenching!
K

Thanks. That gives me somewhere to start.
--
1993 240 Classic; 1993 945 Turbo; 1992 944 Turbo; 1997 850 GLT