Heater stuck on
- Thread starter andyslade
- Start date
One or both heater control valves are siezed closed or partially closed.
Richard Savage
New member
.............. and / or the associated control wire(s) / lever(s) aren't correctly operating the valves!
R.
R.
Check out this link.
http://content3.eu.porsche.com/prod/pag/classic.nsf/intenglish/classic_originalparts_originalparts
Select 911
1984-86
Page 98 of pdf file for exploded view of what we are talking about.
http://content3.eu.porsche.com/prod/pag/classic.nsf/intenglish/classic_originalparts_originalparts
Select 911
1984-86
Page 98 of pdf file for exploded view of what we are talking about.
Richard Savage
New member
Andy
If you need it, try this! As Geoff advised, Page 98.
R.
If you need it, try this! As Geoff advised, Page 98.
R.
zwhitea
Member
I replaced both of mine as they beyond repair... If you are lucky then you may just be able to replace the springs and use some silicon grease and get them working again.. If you do have to replace them they are cheap to buy (£44 each), but a pig to get the old ones off... even though they are only held in place by 3 10mm nuts, because if you break the studs you have a real pain...
If you do need to replace them I would leave it to the winter and remove the hoses and or block off the heater boxes manually... unless you have the time and money for someone else to do it..
If you do need to replace them I would leave it to the winter and remove the hoses and or block off the heater boxes manually... unless you have the time and money for someone else to do it..
Thanks for the help.I think i will have a look underneath the car and see if i can turn the heat of manually ,and worry about it in the winter!
Also,the car has a limited slip diff,and when turning into junctions,it makes a sort of grumbling noise from the gearbox.Is this normal with a linited slip diff?
Regards,
Andrew.
Also,the car has a limited slip diff,and when turning into junctions,it makes a sort of grumbling noise from the gearbox.Is this normal with a linited slip diff?
Regards,
Andrew.
The LSD's do make noise on tight turns. It's normal. Some people say different oils/additives reduce the noise.
With the heater flaps (under the car) you need to move them so they are open and you can see inside to allow the hot air to escape and not be forced to inside the car.
With the heater flaps (under the car) you need to move them so they are open and you can see inside to allow the hot air to escape and not be forced to inside the car.
westernair
New member
Andrew,
I've just dealt with exactly the same issue on my 3.2. The valves were free and rotating correctly etc. but I was still getting roasted in the car especially when my windows and roof wouldn't open recently due to a stuck relay!!
I found that if I loosened the nut holding the end of the cable to the valve, and rotated by hand I found a bit more movement in the valve such that the flap was actually springing against the walls of the duct. If you shine a torch through the open valve you will see that the actual oval flap itself has a white rubber seal which is meant to seal against the duct. In my case just a tiny gap was obviously letting a lot of heat through. My seals are in excellent condition as the car has only done 30K. The effectiveness of this mod obviously depends on how worn yours are. When I tightened the nut I thought my problems were over but alas the springiness in the gasket seemed to push the cable back, taking up slack elswhere in the cable or operating rod inside the car. So I therefore 'tricked' it as follows. Set the rotary dial in the car to no.3 then rotate the valve (with the nut loose) so you are pushing the white seal really tightly then with your other hand tighten the nut. Do this on both sides then set the dial to zero. (Remember to have ign. switched on during all this but not too long or you will cook your coil). You will see that the valve is now closed much more tightly and in my case I now have wonderful cool air blowing on my feet whilst driving along! Whether this adjustment will reduce the max temp I can get during the winter remains to be seen but as the heater is so hot anyway I can't see it being an issue. I first tried the above with no.2 position but no.3 sealed much better. You need to check that the servo motor stops as the seal goes tight otherwise it could strain the motor.
Anyway, give that a try, it only took me 10mins and well worth the result!
Good luck,
Peter
I've just dealt with exactly the same issue on my 3.2. The valves were free and rotating correctly etc. but I was still getting roasted in the car especially when my windows and roof wouldn't open recently due to a stuck relay!!
I found that if I loosened the nut holding the end of the cable to the valve, and rotated by hand I found a bit more movement in the valve such that the flap was actually springing against the walls of the duct. If you shine a torch through the open valve you will see that the actual oval flap itself has a white rubber seal which is meant to seal against the duct. In my case just a tiny gap was obviously letting a lot of heat through. My seals are in excellent condition as the car has only done 30K. The effectiveness of this mod obviously depends on how worn yours are. When I tightened the nut I thought my problems were over but alas the springiness in the gasket seemed to push the cable back, taking up slack elswhere in the cable or operating rod inside the car. So I therefore 'tricked' it as follows. Set the rotary dial in the car to no.3 then rotate the valve (with the nut loose) so you are pushing the white seal really tightly then with your other hand tighten the nut. Do this on both sides then set the dial to zero. (Remember to have ign. switched on during all this but not too long or you will cook your coil). You will see that the valve is now closed much more tightly and in my case I now have wonderful cool air blowing on my feet whilst driving along! Whether this adjustment will reduce the max temp I can get during the winter remains to be seen but as the heater is so hot anyway I can't see it being an issue. I first tried the above with no.2 position but no.3 sealed much better. You need to check that the servo motor stops as the seal goes tight otherwise it could strain the motor.
Anyway, give that a try, it only took me 10mins and well worth the result!
Good luck,
Peter
I'm having the same problem but notice that the footwell fans run all the time even when the control dial is set to 0. Someone has replaced the control in the past and I think I read that the control unit differs between turbo and standard in that the turbo version is set to run all the time due to a lack of blower motor in the engine bay. I think mine may therfore be a turbo control. Any comments ?
I had this and forget exactly what caused it. I was either of these...
1. Adjustment. The servo motor needs to close the heater flaps near the rear wheels, it does this via cables. My car when purchased had these cables cable-tied so tight by an idiot that the system couldn't work.
2. Fusebox. In the engine bay on the left there is a removable panel. Behind the panel there is a fuseblock, this gets a hard time compared to the ones in the luggage compartment. You may need to renew it and the fuses. It is not outrageously expensive from the main dealer.
1. Adjustment. The servo motor needs to close the heater flaps near the rear wheels, it does this via cables. My car when purchased had these cables cable-tied so tight by an idiot that the system couldn't work.
2. Fusebox. In the engine bay on the left there is a removable panel. Behind the panel there is a fuseblock, this gets a hard time compared to the ones in the luggage compartment. You may need to renew it and the fuses. It is not outrageously expensive from the main dealer.
alex.powell
New member
I went for the third option:
Throw the servo away and go with the manual cs version with two little handles that always work!!!
Throw the servo away and go with the manual cs version with two little handles that always work!!!
How does that work in traffic Alex? Coming home from work is spent in traffic [
]
The automatic system works overtime in traffic constantly regulating the amount of heat.
]The automatic system works overtime in traffic constantly regulating the amount of heat.
alex.powell
New member
i don't adjust it that much. The car has been on a bit of a diet recently. I've lost the cabin blowers, air distribution boxes, fresh air blower and wired the screen vents directly onto the heat. it's on either a little or a lot; having said all that, i don't have to deal with traffic on my daily commute. I also made use of the hole where the regulator thingy was to house my hazard switch as i don't have a center console either anymore...
I removed my console from my 930. I would've done the same in my 911 except it has the immobiliser thingy in it...
My hazard light button is near my ignition key. I didn't know the later cars were different.
Want to save some more weight and swap your G50 for my 915 ? []
My 911 weighed 1160kg with half a tank of fuel.
You'll be wanting to get an electric heated front screen next [8D]
My hazard light button is near my ignition key. I didn't know the later cars were different.
Want to save some more weight and swap your G50 for my 915 ? [
]My 911 weighed 1160kg with half a tank of fuel.
You'll be wanting to get an electric heated front screen next [8D]
alex.powell
New member
where did you get yours weighed? I've wondered if the scales at madingley mulch would be any good? I'm keeping the gearbox, spent a grand refurbing it and will need it for next engine .
Hehe I was only kidding about the gearbox, hence the [].
Did it work any better after the rebuild?
I had my 911 weighed when I had the corner weights done on electric scales.
I'm not sure how one goes about using a public weigh bridge.
I had my 930 weighed at the scrap metal merchant off Newmarket Road, Swann Road industrial estate.Weighed 1225kg with very little fuel in. You could give them a call first and maybe offer them a fiver or something. I asked them when I took some scrap there.
The only risk is maybe getting something stuck in your tyres [:'(]
].Did it work any better after the rebuild?
I had my 911 weighed when I had the corner weights done on electric scales.
I'm not sure how one goes about using a public weigh bridge.
I had my 930 weighed at the scrap metal merchant off Newmarket Road, Swann Road industrial estate.Weighed 1225kg with very little fuel in. You could give them a call first and maybe offer them a fiver or something. I asked them when I took some scrap there.
The only risk is maybe getting something stuck in your tyres [:'(]
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