Detoxx

Need a little troubleshooting help. Recently bought a 993 and on the way home, 200+ miles, noticed the drivers side sill got very warm. I could feel the heat on the sill, under the carpet on the left side of the driver seat and the seat belt housing. The ac was running and car run relatively cool with respect to oil temps. Did some searching and couldn't really find anything. Any idea?

nile13

Freon runs from the compressor in the engine compartment to the condenser in the driver's side front fender. What you are feeling is probably how A/C pipe on the way to condenser.

The passenger side should be warmer as it has oil going to the oil cooler on that side.

Detoxx

The drivers side is warmer. I noticed this due it feeling like there a heater under the drivers seat near the left seat rail. I wonder if this the high pressure ac line that is giving off that much heat. Also is there anything else on that side that possible transferring heat down the drivers side sill. It not quite hot to touch, but considerably warm

TMc993

Heat runs from the engine through the sills. You may have a heater valve malfunctioning.

Detoxx

Thanks I'll start digging for a heater diagram to determine locations of the valves.

Detoxx

So I suspect it's the flapper valve as indicted in this thread
https://rennlist.com/forums/964-foru...-question.html

k722070

the heat tube is under that sill, hot air is pushed into the tube but is stopped from entering the cabin by the servo in the footwell. after 200 miles the tube is hot and the sill is hot.

Detoxx

Thanks, after doing a bit of scrounging the forums and this image it makes sense.
http://www.bergvillfx.com/images/HVACoverview.jpg
Basically if understand this correctly, the flaps located in the footwells allow or deny heat to the vents located in the dash based on the settings of the control unit. When these flaps are closed heat dumps out of the vents located around the rear wheel. The venting of heat only occurs when the values are closed due to the pressure differential. However when closed the heat can and will radiate up the door sills even though its venting at the wheel wells as the valve is located in the front of the cabin and not at the rear preventing the heat from traveling forward. The venting of heat only occurs when the values are closed due to the pressure differential.

ToreB

Detoxx, you are completely right.
Normally there should be no air flow through the hoses going to the mixers, and thus less heating of the sill and surroundings.
If there's a small air leak at the driver's side mixer flap, this will allow a small amount of hot air to flow through the heat hoses to the cabin and maybe increase the heating of the surroundings around the hose.
Any flap malfunction could easily be spotted by removing the mixer flap mechanism from the heat hose, a 5 minute job. The flap position is somewhat adjustable by loosening the fastening screws and turning the servo mechanism.
Cheers,

Detoxx

Thanks, I'll trying a look at the mixer flap mech sometime this week.