A/C compressor pulley/plate and bolt

[clivethegadget]

My A4 (B6) 1.9 TDI 130bhp air-con has stopped cooling recently.
The system was regassed, but I was told I would need a new compressor as the pulley was going around, but not turning the compressor.
I've read elsewhere in the forum that the front fixing bolt and the cover can fall off ... and this could cause this problem.
I looked in the bottom plastic tray, but did not find any parts there.
However, I did remove the plastic air cowling and put my had down and felt the front face of the pulley.
I can feel a hole in the centre where a bolt should be .... so the bolt seems to be missing !
I can also spin a plate around (which seems to have a slot in it).
Now, I can go find a replacement bolt (if I have any idea of size) and loctite it in ... but is there anything else missing ?
The plate that spins ... does this sound like the plate that sometimes goes missing ? have I been lucky and this plate has stayed on ... or is there another plate which should go on top of this before the bolt is inserted ?
Any help (including any ideas on what size bolt !) greatly appreciated !
Thanks

[tony-1977]

I've the exact same problem here! No cooling, and recent re-gas made no difference I've no idea where to locate this pulley where the bolt goes? Could anyone help me? Thanks... :-)

[clivethegadget]

The compressor is located low down behind the bottom left hand side of the radiator when standing at the front of the car peering in.
It is driven by an auxilliary belt. .... looks a bit like another alternator at first glance !
The ribbed belt goes around a grooved pulley wheel attached to the front of the compressor.
If you remove the plastic air intake at the top LHS of the engine bay (the flat ducting which is in two parts), you can just about squeeze your arm down beside the large tubing and touch the front edge of the pulley (if you arm is slim enough!).
On my A4 the front edge of this pulley has a disk which seems to spin by hand without moving the pulley wheel itself. From what others say, this seems to operate like a clutch and drive the shaft whe engaged.
I'm not sure what triggers it to engage though !
My plate feels like it has a hole at the centre (There is no way I can get any sort of angle to be able to actually view this plate).
From what others have said, I would have thought that there should be a bolt in this centre hole.
I have tried inserting some bolts with my fingertips at full stretch ... but no joy. I have tried an M6 20mm bolt and even some very thin bolts ... but nothing seems to go into the hole. I am now wondering if a) there is actually no hole there .. and no bolt every belonged there ... or (b) the bolt has sheared off completely (in which case I'm stuffed !)
I would be interested to know what you feel (or see) at the centre of this pulley.
If you have a slipping bolt then others have fixed this problem with a little bit of loctite and tightened it up with a spanner (if its not already fallen off along with the plate into the plastic sub-tray beneath the car.
Let me know what you find !

[tony-1977]

Thanks, I'll take a look!!

Does anyone know which fuse(s) / relay(s) are used in the Climate Control system?

Thanks :-)

[tony-1977]

OK guys.... I've found the compressor. The disk-like plate on the front does rotate freely. It has a 10mm bolt attached to the middle (I think it's a bolt??) I've checked over this thouroughly and it does NOT spin when I have the air con on, even though the pulley is turning.. The two fuses for the air con (1 and 6) are fine. Is there a relay I can check? BTW, I can't find where the wiring goes to the compressor? I want to check the connections here when I can find them. Can anyone point me in the right direction of this?

Thank you ... :-)

[tony-1977]

Anyone? :-)

[clivethegadget]

I'm afraid I don't know too much about the air con myself.
This pdf might help you ... there is some diagram of the aircon circuitry.
http://www.volkspage.net/technik/ssp/ssp/SSP_254.pdf
I am a bit confused as the Haynes Page 3.11 manual says "As no clutch is fitted to the air conditioning compressor (the compressor operates continuously), do not operate the engine if it is known to be short of refridgerant, as this will damage the compressor."
No clutch ??? Really ? The comments in this forum suggest otherwise, and the spinning plate which does not turn with the pulley seems to suggest that there is a clutch.
Surely, the fact that there is wiring to the compressor must be because there is a clutch, otherwise it would only need to be directly turned by the belt and pulley.
I think the aircon control unit sends a variable signal on wiring to the compressor clutch .. but I don't know if anyone can confirm this is so.
In my case, the central bolt which should fix the clutch plate to the pulley is either missing or sheared off ... I can't really be sure as I cannot get a position to see. But I cannot get anything to fit by touch into the hole where the bolt should be .. even with a very slim bolt to try to check the hole's depth. Perhaps the Audi garage sheared it off when they tried to tighten it ... I'll never know.
I am unsure if it is worth pursuing work to improve access to the compressor and perhaps drilling out/removing any sheared bolt.
Then perhaps I can insert a new bolt and locktite/screw it in.
Is it more likely that the clutch mechanism is knackered and would it be worth trying to buy an old compressor to swap clutch parts ?
Otherwise I will have to go for a full new, expensive compressor.

[RickT]

Hi,

This happened to my dad's, the plate fell off bolt and landed on the under tray,

We put the end plate back on, locktight on the bolt and fasterned back on and its been fine since. (touch wood)

Rick

[tony-1977]

Hi,

This happened to my dad's, the plate fell off bolt and landed on the under tray,

We put the end plate back on, locktight on the bolt and fasterned back on and its been fine since. (touch wood)

Rick


I wish mine was this simple!! I'm tearing my hair out!! :aargh4:

[leeoz]

Clive, Tony - have you plugged the car into a VAG-COM - I have recently had loads of air-con issues and in the end it was the G65 Pressure sensor, because that had failed the system would not pull the compressor in (engage the clutch) and there was no cooling, just loads of toastie hot air.

If you can get it plugged in it might save a lot of grief, the sensor cost £49 and 5 mins

[tony-1977]

leeoz... Thank you for the suggestion. I am so tempted just to change this sensor. I do not know anyone who can VAG-COM my car to get a fault reading. I'm in Newcastle upon Tyne if anyone can help, in return for some beer :-) Am I right in assuming this is the sensor next to the N/S headlight on the air con radiator? I'm also considering looking for someone who I can swap the sensor with (known working sensor) to assist fault finding!

[tony-1977]

I've taken the plunge and ordered the G65 sensor. Thursday delivery. Will report back with results :)

[tony-1977]

Replaced the sensor. The compressor is still not engaging. Arrrggghhh!!!

Any more suggestions? I've no vag com so unable to plug in :(

[tony-1977]

Forgot to mention, the air con radiator fan does not kick in either? Are the two linked? I can't seem to find any relays on the car, are there any hidden away anywhere?

Thanks, Tony. :)

[nevo]

disconnect the compressor connection and see if you get any voltage ,got same probs lems with my A4 no codes ,no fan, my understanding is that there is no clutch as such,and when ecu asks for cooling it speeds the tickover up slightly,are you getting this?mine certainly isn't.only noticed mine yesterday so early days yet,reading another post on the A4 page another guys done a regas and still no a/c.

[tony-1977]

disconnect the compressor connection and see if you get any voltage ,got same probs lems with my A4 no codes ,no fan, my understanding is that there is no clutch as such,and when ecu asks for cooling it speeds the tickover up slightly,are you getting this?mine certainly isn't.only noticed mine yesterday so early days yet,reading another post on the A4 page another guys done a regas and still no a/c.

Where is the compressor connection?

Can't seem to find it! :aargh4:

No tickover increase at all. Heard rumours that disconnection battery for a few mins helps? Not so sure, though.

Thanks

[nevo]

Check clive the gadgets link page 77 you'll see it at the back block side,forget all those battery disconnecting stories.

[tony-1977]

Well it's time to get my hands dirty. Just got my VCDS cable and software through. Ran a fault scan. Only getting a dodgy fuel temp sensor, open to plus, whatever that means?? Cleared it and it returned. Not sure if this would affect the climate control!!! Grrrrr.............

[nevo]

When your fuel temp sender goes the ecu uses the coolant temp sensor to determine fuel temp,so needs changing,will have a slight effect on mpg,use the air con section and look for fault codes.

[tony-1977]

When your fuel temp sender goes the ecu uses the coolant temp sensor to determine fuel temp,so needs changing,will have a slight effect on mpg,use the air con section and look for fault codes.

Thanks Nevo :beerchug:
Will change the fuel temp sensor. Still getting 48-52 MPG, more on the motorway!

There's no fault codes in the air con section! :aargh4::confused::zx11:

[nevo]

The fuel sender can wait its no big deal,I think mine needs a regas,I'm waiting for a mate to come back off hols to do it ,don't want to pay full price and like you still no cold air.whats the pipes feel like where they go through the bulkhead?are they cold,do the vents blow cold air when you start the car from cold,just thinking whether one of your flap motors are sticking just a few thoughts to digest and think about.

[tony-1977]

The air is hot when the climate control temp is increased, and "lukewarm" when on "LO" and the flaps can be heard to be moving. Just no rad fan or compressor. The pipes, where they enter the bulkhead are not ice cold, just "normal".

Fuses are OK, beginning to think a relay, as there's no click when I turn the CC on. But no idea which relay it is! Nothing in owners handbook!

Tearing my hair out now! (what's left of it!) :(

:beerchug:

[Dave Avant]

Think I'm in the same boat as you Tony!!

Air con was working fine, then nothing!! Re-gased, vacuum checked, no faults logged, fuses fine.

I replaced the G65 pressure sensor, still nothing. took the under tray off. With the engine running, the pulley turns with the centre part remaining still. I can see the end of the centre shaft with slines on it. I've checked the power and I get 9.6 volts to the plug ontop of the compressor.

Has anyone got a pic of the pulley on the compressor, not sure if you should be able to see the splines on the shaft as most compressor pics I've seen seem to have a plate on the end. Mine has a hole in the middle with the shaft with splines on. I noticed a member said their Dad's end plate fell, just wondering if its this!?

Any pics of the compressor on an A4 anyone?

[Dave Avant]

Hmmm, just checked the graphic of the compressor in the PDF posted on the 1st page of this thread, if thats how its supposed to look then I think mine is missing the centre plate!?!!? Wonder if it is the case and whether this can be bought as a seperate item!?!?

Doh!

[tony-1977]

Hmmm, just checked the graphic of the compressor in the PDF posted on the 1st page of this thread, if thats how its supposed to look then I think mine is missing the centre plate!?!!? Wonder if it is the case and whether this can be bought as a seperate item!?!?

Doh!

Could be a good start! Mine still has the centre plate, which spins freely by hand, but does not spin when the CC is on! I've heard the centre plate can come off with time!

How did you access the compressor connection? I can't seem to get to it?? I might try and hard-wire the compressor to the battery to test (with in-line fuse).

Incidentally, did you say there was only 9.6 volts at your compressor? I'm no expert, but should it not be 12?

Does your radiator fan kick in with the CC / AC? Cos mine does not!

Need help chaps!! Don't want to have to pay some one just yet!! :aargh4:

I've also replaced the G65 to no avail.

Dave Avant, if you try and get a pic of the front of your compressor, I'll compare to mine??

Wondering if Crasher would be able to help us here!!! :beerchug::beerchug:

[Dave Avant]

Hi Tony,

Do you reckon you can get a pic of the front of your pulley? I'll take one of mine! ;)

Mine does look like there is something missing!!

My fan doesn't come on as it only comes on to cool the gas once its been activated and the compressor is the first part in the system to run. The plug is ontop of the compressor. I got to mine from underneath. Not sure what the voltage should be, but when activated it went to 9 volts on my tester.

I do remember now hearing something jangle and knock under the car a bit ago, just thought I'd run over something, but can't remember where it was!!!

[tony-1977]

Hi Tony,

Do you reckon you can get a pic of the front of your pulley? I'll take one of mine! ;)

Mine does look like there is something missing!!

My fan doesn't come on as it only comes on to cool the gas once its been activated and the compressor is the first part in the system to run. The plug is ontop of the compressor. I got to mine from underneath. Not sure what the voltage should be, but when activated it went to 9 volts on my tester.

I do remember now hearing something jangle and knock under the car a bit ago, just thought I'd run over something, but can't remember where it was!!!

I've just tried taking a pic, but the only camera I have is my iPhone :p, and as it has no flash, I can't get anything :zx11:. Basically, it looks just like the image on page 77 of the PDF file in this thread. can you spin the front of the compressor by hand, not what the pully is attached to, put your finger on the front and it should turn.

I can't get my car high enough off the ground to get right under to get the connector off. If your a fat barsteward like me, it can be difficult :biglaugh:. Although I can just see the connector now, just don't wanna pull it off and not be able to get it back on :aargh4:.

The jangle yopu heard could have been the clutch plate on the front of the compressor falling off?? Try turning it by hand. You should see a bolt in the centre of this, which holds it in place. I know someone on here found his sitting on the under-tray!

Gonna invest in a couple of axle stands od raise the front as high as I can to investigate further. The wires feel all in place though :aargh4:.

[Dave Avant]

Couldn't get a pic either, not enough room.

Doh, I think I'm 99% sure its fallen off!!! :aargh4:

I have no plate on the front, just a hole with a small shaft in the middle with splines on it and not bolt in the middle, just a small threaded hole in the middle of the shaft!!

Anyone know if this bit can be bought seperately!?!?

Or anyone know an AC place that might have old ones I can nab the pulley plate off?

Why has it taken 7 years to just fall off!!!

[nevo]

try auto air con parts,tel 0845224 0572,also try your local audi you never know its a common problem so they may stock it.see if you can get a pic if you tackle it .

[Dave Avant]

try auto air con parts,tel 0845224 0572,also try your local audi you never know its a common problem so they may stock it.see if you can get a pic if you tackle it .


Just tried both Audi and air con parts and both had same answer - complete compressor only!!! Bowlocks!!

Need an old knckered compressor me thinks!!

[tony-1977]

Try a breakers??

http://www.google.co.uk/#hl=en&source=hp&q=audi+breakers&aq=0&aqi=g10&aql=&oq=audi+break&gs_rfai=&fp=3309f3d1f1c925d0

:)

[nevo]

Got my regas today,much better lovely cold air, 135 gramms recovered,500 recharged plus 12ml of pag,so its leaked slowly, I've had it three and a half years and its not been touched so cant complain.

[tony-1977]

Well I've given up! Got it booked in to an air conditioning specialist this afternoon :(

Compressor is still not engaging!

No fault codes. Condensor plate is present and spins freely by hand. Re-gassed. No leaks. G65 sensor changed. Fuses all ok. Econ light goes out when pressed.

Getting sick of driving round with both front windows open to keep cool!

Got my wallet at the ready. Arrrggghhhhhhhhhh.........!!!!!!!!!

Will keep you lot updated when I collect it later on :)

[tony-1977]

Well that's that..... I need a new compressor :( There is current there, and the clutch plate is present. Just burnt out with age :(

Arrrggghhhhhhh!!!!!!!!! Anyone got a compressor?!?!?!?!?

[Dave Avant]

Well that's that..... I need a new compressor :( There is current there, and the clutch plate is present. Just burnt out with age :(

Arrrggghhhhhhh!!!!!!!!! Anyone got a compressor?!?!?!?!?


Doh!!

Hmm how does the compressor burn out, it has pistons like a mini engine, so long as there is gas there it should be OK, I'd expect it to get rattly before dieing!!

Try Autoklima24 for a compressor, in germany, but seems decent, have ordered a new pulley from them this week!

[tony-1977]

Not sure how it burns out!! I've owned the car for a couple of months but the air con had not worked for 18 months ( I know the prev owner). All tested, all sensors OK and there is current at the compressor. Assuming internal electrical fault in comp?? Car has 148k on the clock and the prev owner NEVER had the climate control off, until it packed up.

[fla]

how do you remove the compressor? I assume that the belt will have to be de-tensioned then presumably you cant run the car until the comoressor is fitted back on? Tony - did you get any pics etc of the change/repair?

[tony-1977]

how do you remove the compressor? I assume that the belt will have to be de-tensioned then presumably you cant run the car until the comoressor is fitted back on? Tony - did you get any pics etc of the change/repair?

I never got the car repaired. It got written off in an accident (non fault) about a week after I posted the above message :(

[badger0505]

Had the same problem with the middle screw unscrewing and splines on shear plate braking off. Was quoted £1165 from VW dealership. Bought a new plate from X8R on ebay for£29.99. took an hour to fit and now have perfect cold air con

[Overdose]

I know this is an old thread, but it is still relevant.
A seemingly common fault when there are no fault codes present, is the clutch plate bolt coming loose and causing the splines to wear. Replacement plate kits are available for around £15.

Another failure mode is on the Delphi pump. This pump has no magnetic clutch, but has a shear plate instead of the clutch plate. This plate has three steel fingers connecting two parts of the plate together and mine have cracked through. It took a while to find it, as it wasn't immediately obvious, particularly as I thought I had a magnetic clutch. The Delphi pump on some VAG cars is operated through the N280 valve and is constantly driven, so you need to be aware of which pump type you have fitted.

I will update with a pic once I've replaced mine.

[bac2ba6]

I'd be interested in this , as looking at changing my plate on the ac pully , only had a very brief look but the center bolt on the plate just seems to turn and never tighten up , or the other way never loosens any more , is it supposed to ?

[Overdose]

I'd be interested in this , as looking at changing my plate on the ac pully , only had a very brief look but the center bolt on the plate just seems to turn and never tighten up , or the other way never loosens any more , is it supposed to ?

It should tighten up, yes. The other half of the plate assembly is held on by three screws and attach to the pulley.

It's not the best access to either see what you're doing or actually manipulate the fasteners.

[bac2ba6]

It should tighten up, yes. The other half of the plate assembly is held on by three screws and attach to the pulley.

It's not the best access to either see what you're doing or actually manipulate the fasteners.

Yeah I jacked it up and took the archliner out

The pully is in front of you then , so better access just seems odd that the centre torx screw/bolt just keeps turning in either direction , maybe it will come out once ive undone the 3 that hold the shear plate on , I'm presuming that the splines are gone on the plate , but for what they cost it's worth a try to swap it 👍

[arman123]

various types of air con compressors fitted here is the method for pulley removal this is for two types

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[Overdose]

This might not be your setup, this is for the clutchless pump/compressor and utilises a shear plate, not a clutch.
3973539736397373973839739

[arman123]

If you could put up the details of the car and year fuel and the engine code it would make it easier