924 -81 heating

[Joakim]

does -81 924 porsche blow warm air only to you feet and/or to windshield?

mine does, is that a fault or what?

[camfella]

I had a similar issue with my 87 924S. Turns out the Bowden cable connected to the interior control arm had become all bent out of shape and was not closing the valve in the engine compartment. I ended up removing the cable connection at the valve and then closing the valve. This solved the heat problem for the moment, issue being that I don't have any heat at any time.

[Joakim]

my cable that moves water valve behind the engine,the cable is broken, but if i manually open it i can get warm air to windshield and foot compartment but those air blowers on top of the oil pressure gauge, the clock and the battery amper gauge, they blow all the times cold air.

is that normal?

[vdubr928]

Yes. Your 81 has a split system. You will only ever get AC from the dash vents.

[Joakim]

I dont have AC

[vdubr928]

Well then I'm not sure. Go to 924Board.org :: Index for real good 924 data. On my 81 the dash vents only service AC. This is why many upgrade to the 944 heater box

[Joakim]

and my one problem is that in winter the engine temperature is normal like in summer, but i cant get interior to heat up, it is cold in my car on winter, if the termostate is faulty, does the engine heat normally, but leaves interior to cold, even it blows warm air from vents?

[vdubr928]

Negative. If the thermostat is bad you will have engine temp problems. Likely your heater core is not getting hot water. Feel the lines and see if they are getting hot. If not check the valve.

[Joakim]

the temperature gauge is like |blue | | | red|

and last night i drove home from work, the outside temperature was about +20 degrees celcius and all the way the 100kilometers the temperature did not go over the first | on rightside of blue. |blue | | | red|

usually, when driving in town low speeds the temperature is on the middle | of the gauge, and if the gauge goes thirth |. then the radiator fan goes on.

does your fan run even if the motor is turned off?

if i turn off the engine when fan is on the fan will keep blowing but at the minimum speed like about 10% when 100% is full speed, im not sure if turning the ignition key makes the differents, meaning when i dont start the engine again.

[tazzieman]

Originally Posted by Joakim

usually, when driving in town low speeds the temperature is on the middle | of the gauge, and if the gauge goes thirth |. then the radiator fan goes on.

does your fan run even if the motor is turned off?

if i turn off the engine when fan is on the fan will keep blowing but at the minimum speed like about 10% when 100% is full speed, im not sure if turning the ignition key makes the differents, meaning when i dont start the engine again.

Joakim - sounds like your radiator fan thermoswitch is working normally. It cycles on and off whilst idling. Depending upon how the relay is wired, it may keep running after you turn off the engine until it cools to the preset temperature.
The cabin fresh air blower (fan) seems to run whenever the ignition is on ; I think that's normal for the '81, that's just Porsche caring for your personal comfort when it detects your presence

[Joakim]

tazzieman: i reliase that

but is that normal engine temperature like i explaned that temperature gauge position?

[tazzieman]

Originally Posted by Joakim

tazzieman: i reliase that

but is that normal engine temperature like i explaned that temperature gauge position?

Since I totally overhauled my cooling system , my gauge does the same. Highway speeds it runs to the left of the blue mark , because wind is passing through the radiator! When I pull up to the lights , the temp creeps up to nearly midway and the fan kicks in pulling it back to the blue mark.

My climate is milder than yours so I installed a low temp thermal switch for peace of mind given our warm to hot summers.

[Joakim]

Originally Posted by tazzieman

When I pull up to the lights , the temp creeps up to nearly midway and the fan kicks in pulling it back to the blue mark.

When I read that, I Laugh on load I dont know why.. maybe because I just woke up

how big lights do you have? :O

[Joakim]

Originally Posted by Joakim

... but those air blowers on top of the oil pressure gauge, the clock and the battery amper gauge....

sorry for quoteing myself..
actually it is not ampr gauge, its only volt gauge

[vdubr928]

Originally Posted by Joakim

When I read that, I Laugh on load I dont know why.. maybe because I just woke up

how big lights do you have? :O

Lol I get it now. They must be hot lights.

Your fan relay is working properly. My 931 (924 turbo) works the same way. It should run at a slower speed when you shut the motor off untill it drops below (probably) 212°



Either heater core is clogged, disconnected, valve not opening, or your heater box is broke.

With the engine warm are the water lines that pass through the firewall to the core getting hot?

[Joakim]

when driving around I can get warm air from vents.. but like in last winter, it was chilly in the car..

even when the core valve was fully open behind the engine, car was so chilly and even the windshield vents was only open and i was driving alone in the car, the windshield almoust frosted.

and that air was warm what it blow out of the windshield vents...
it did not get hot.

[Joakim]

btw

is there way to test termostate?

[vdubr928]

Originally Posted by Joakim

btw

is there way to test termostate?

You can boil it in water with a thermometer.

[vdubr928]

Originally Posted by Joakim

when driving around I can get warm air from vents.. but like in last winter, it was chilly in the car..

even when the core valve was fully open behind the engine, car was so chilly and even the windshield vents was only open and i was driving alone in the car, the windshield almoust frosted.

and that air was warm what it blow out of the windshield vents...
it did not get hot.

Does the heater fan run when you change speeds? If so then your heater core may be clogged. This will slow the flow and thus make cooler air. I do not think you can get warm air from the dash vents. My 81 does have ac but the dash vents are a completely different system and only blow cold air. You should have nice warm forced air from the defrost and or floor vents. If not check fan speed and flow.

[Joakim]

I dont talk about those dash vents. like vents on top of the clock.

I talk about those "defrost(windshield vents) and or floor vents(foot compartment)"

the air coming from defrost on winter could not keep window from frosting..

yes the fan runs on different speeds when I move the speed slide..

is there a easy way to take apart the fan motor and get it run little smoother?, like greesing the bearings and so on and cleaning it...