Screaming Fan on 924 and early 944

[vincematthews]

I don't suppose there is a quick way of getting to the heater/fresh air fan without taking out the dashboard?
I've tried lubricating the upper bearing and using electrical cleaner on the brushes but I can't get to the fan's lower bearing to lubricate it.
I've got the fuse out at the moment but that's obviously no good if the windscreen needs demisting.

Is the dashboard out a long job? Also is the fan still available or is it a silly price?

Cheers guys

 

[russmw]

Hi,

This is also a job I've got to look at and the dash is pretty much the only part of the car I haven't removed. I did try via the fresh air intake in the scuttle panel but no matter how much I tried to convince the motor to come out it was having none of it, it did however feel as though there wasn't much holding it back.

I plan on removing the dash as I also need to refit the dash cap so its 100% snug and understand its not a massively difficult job. No idea if the fan is still available.

thanks

 

[vitesse]

I've never looked at either Mike's heater motor. (924) or either of ours(924S) other than ours get small particles within despite the protection round the skuttle mounted motor & sound like the days when we used to stick some cardboard on our bikes to give a " motor" sound.
Generally ,eventually they seem to get rid of the detritus.
However I recently had to have replaced, the fan motor in the BMW 530D heater which was recommended because of the strip down cost involved at getting to it because the speed resistor electronic controller attached to the motor had failed.
I Asked for the old motor which was reluctant to run but after checking the wiring,commutator etc for continuity,I dosed the small oilite type shaft bearings several times rotating the rotor to & fro until it ran freely again then attached my battery charger set on high( heater fuse is 40 amps !) & it whizzed away -dropped the charger to -trickle- & it still whizzed away.
It is a simple open cage device with substantial windings in a hybrid pressed steel / plastic mount made by VALEO IIRC so possibly the Porsche motor is pretty similar.
In my experience over the years it is usually those oilite bushes that dry up causing a heavy starting load & plus screeches.
Perhaps a good dose of something like GT85 sprayed in would reach the bottom bearing but wouldn't harm anything else in its path-use an extension probe from small bore silicone rubber,maybe.
Colin

 

[vincematthews]

Hi,
This is also a job I've got to look at and the dash is pretty much the only part of the car I haven't removed. I did try via the fresh air intake in the scuttle panel but no matter how much I tried to convince the motor to come out it was having none of it, it did however feel as though there wasn't much holding it back.
I plan on removing the dash as I also need to refit the dash cap so its 100% snug and understand its not a massively difficult job. No idea if the fan is still available.
thanks

Yes I'm probably being chicken - I've almost certainly done much more difficult jobs than dash out. It looks to me like the fan motor is held in place between the two halves of the plastic heater housing which in turn are retained by spring clips. Not sure if you have to disconnect the water side of the heating system though.

 

[vincematthews]

In my experience over the years it is usually those oilite bushes that dry up causing a heavy starting load & plus screeches.
Perhaps a good dose of something like GT85 sprayed in would reach the bottom bearing but wouldn't harm anything else in its path-use an extension probe from small bore silicone rubber,maybe.
Colin

Looking at the photo, I think it would be difficult to position a tube with a 'U'-bend on the end to lubricate the lower bearing without covering the windings? Maybe I also need to see if I can get the brushes out to see how much life they've got left. I had trouble with a power shower failing and all I did was take out the brushes, put them back, and it's been working ever since.

A cardboard strip, clothes peg and a push bike - those were nice simple days . . .

 

[Waylander]

just for a guide

the fan motor is still shown with a price in PET2 so might well be available
321 819 021 Fan Motor £162.73 Inc vAt

 

[CarreraRSR]

On early fans the only way of getting them out is dash off, heater box out, split in half, lubricate and put all back together. A days work in anyones books. I have read stores of going in from the top of the heater box from the engine bay, melting plastics to remove the fan motor and then reinstalling with copious amounts of glues/plastics etc. I did mine a few years ago by doing the former. Put all the plastics in the dishwasher at a low heat, washed all the debris out. The foams that seal the internal flap had deteriorated so used new neoprene foam to reseal. Hopefully it will last another 40yrs.

 

[vincematthews]

just for a guide
the fan motor is still shown with a price in PET2 so might well be available
321 819 021 Fan Motor £162.73 Inc vAt

Thanks
I think the original Bosch part number is 0.130.007.023 - if I get the fan out, I'm hoping it'll just need lubrication and maybe new brushes as that seems quite expensive.

On early fans the only way of getting them out is dash off, heater box out, split in half, lubricate and put all back together. A days work in anyones books. I have read stories of going in from the top of the heater box from the engine bay, melting plastics to remove the fan motor and then reinstalling with copious amounts of glues/plastics etc. I did mine a few years ago by doing the former. Put all the plastics in the dishwasher at a low heat, washed all the debris out. The foams that seal the internal flap had deteriorated so used new neoprene foam to reseal. Hopefully it will last another 40yrs.

Yes, I'd heard you could cut the struts holding it in place and pull it out through the top - difficult to line up on re-assembly I should think.

Did you have to disturb the water system/heat exchanger?

Cheers

 

[Waylander]

£162 for a fan motor is dam cheap by Porsche standards, if they can charge £300 for a clutch slave cylinder, or £3200,00 for a 964 C4 brake accumulator, which I fixed for £70

 

[vincematthews]

£162 for a fan motor is dam cheap by Porsche standards, if they can charge £300 for a clutch slave cylinder, or £3200,00 for a 964 C4 brake accumulator, which I fixed for £70

Sorry, didn't make it clear, I was talking about by my standards! []
plus I think I could get it pro re-built for half that.

 

[Waylander]

Absolutely get it fixed serviced overhauled, I fix everything, rebuild starters, alternators, Brembo calipers, gear linkages and all sorts

i was just saying that it was not expensive for Porsche

 

[vitesse]

I've just consulted my Haynes manual(1976-1982) which suggests that there is no need to remove the dash,just the centre console,glovelocker,heater matrix,obviously all the bits that get in the way,bend a retaining clip out of the way & remove heater box from the passenger side.
Then unclip the box etc.
I do have access to a full official Porsche Workshop manual (from Mike ,whose car I have posted about ) if necessary.

 

[vitesse]

Should have added:-Also remove the dash speaker grille ,then the speaker which gives access to the clip/bracket supporting the heater box which has to be twisted away to release the box .

Whilst I have never removed the whole unit ,this thread has reminded me that I once replaced the heater matrix many years ago but can't remember now whether it was on our earlier 924 Lux or my wife's 924S (we've had it since 1991!)
In either case ,the job entails similar procedure of draining the coolant,removing the centre console,radio,etc ,disconnecting the 2 hoses in the engine bay right next to the bulkhead ( the worst part) & sliding the matrix out sideways into the passenger compartment.
IIRC the bad bits include trying to avoid residual water soaking the floor carpet & a bad back.??

 

[Robin]

I had a problem with an occasional screaming fan which I think I have now cured ?
I had a problem with water getting into the drivers footwell after heavy rain. It appeared to come through the heater and down the pipe to the footwell. Looking at the plastic cover over the heater unit in the scuttle area, I saw that the plastic cover was loose and appeared to be held in place by putty! I lifted the plastic cover and pulled it out from under the bottom of the windscreen plastic part, it was a tight squeeze. This uncovered the fan unit which is one of the drum type. I cleaned off all of the putty and prepared for the replacement of the plastic cover. While it was uncovered I put 3-in-one oil into the holes of the motor to lubricate the end bearing. This silenced the screaming fan. I put a thick bead of Silicone mastic in the groove in the plastic cover and forcefully pushed the cover back in place and weighed it down for a couple of hours. = Job done, no water leak and no noisy fan, Happy driver!

 

[Robin]

Here is the replaced cover.

 

[vitesse]

|Never had a screaming fan but have occasionally had small leaves /pieces get in there & cause chopping noises until small enough to dissipate into the cabin (or somewhere)