AC Compressor part number and compatability

[Bowlerwell]

I got a spare compressor with my RS2, but I want to know if It is compatable.
It is a 4A0260805AD, which as far as i'm aware, is compatzable with the following models:
AUDI 80, 2.6 6 Cyl, Petrol, Sep 91 to May 96: Part 14-7584
AUDI 80, 2.8, Petrol, Oct 92 to /: Part 14-7584
AUDI A6, 2.4, Petrol, Jun 94 to May 97: Part 14-7584
AUDI A6, 2.5 Tdi, Diesel, Jun 94 to Aug 97: Part 14-7584
AUDI A6, 2.6, Petrol, Jun 94 to May 97: Part 14-7584
AUDI A6, 2.8, Petrol, Jun 94 to May 97: Part 14-7584
AUDI A8, 2.8 V6, Petrol, Jun 94 to /1996: Part 14-7584
AUDI S6, 2.2 20V, Petrol, Jun 94 to May 97: Part 14-7584

But the compressor for the RS2 is (as far as I can gather):

Compressor for AUDI 80, 2.2 20V TURBO, Petrol, Feb 93 to Jul 95: Part 14-9695,
This part matches any of these Original Equipment Numbers, (if shown) 8A0260805AC / 8A0260805AA / 8A0260805AF,


Question is, is my 4A0260805AD compatable with my RS2?



Thanks,
JohnB

[Bowlerwell]

Nobody know?

[johne]

As far as I am aware there is no difference between RS2 & S2 compressors. The main difference is between the compressors for R12 and R134 refrigerant. R134 is used on later cars and the compressors have a different pitch on the mounting bolts so need a different mounting bracket to fit. Bottom line is, if the compressor fits your bracket, has a V belt pulley and the pipe connectors match up it will do the job.

[Bowlerwell]

Thanks.
I just don't want to go to the bother of taking the front bumper, aux rad, etc. off, only to find that it doesn't fit...

[S2central.net]

As far as I am aware there is no difference between RS2 & S2 compressors. The main difference is between the compressors for R12 and R134 refrigerant. R134 is used on later cars and the compressors have a different pitch on the mounting bolts so need a different mounting bracket to fit. Bottom line is, if the compressor fits your bracket, has a V belt pulley and the pipe connectors match up it will do the job.

Not sure its quite that simple now... Staying with R134a for now... The compressors for digitally controlled AC (LHD only on B3/B4 unfort) are different from manual controlled ones.

Now it might well be that these different types have different belt pulleys so they can't be fitted to wrong vehicle - that would be a nice trick. Just haven't seen the different types all sitting alongside each other to know.

I'll have a quick look at the parts system here.


Paul

[Bowlerwell]

My RS2 is LHD, with the climate control.

The part numbers stated above didn't distinguish between RHD and LHD...

[S2central.net]

Jees the family album is complicated on this one... And I *think* it has some errors.

RS2 only shows 8A0 260 805 AF which has a V-belt - same as R134a S2.

It doesn't make any mention of LHD or RHD or AC variants...

I'm sure I read somewhere that only compressors with the poly belts have the controller in them for digital systems. 4A0 260 805 AH as used on the AAN engined S4/S6 is such an example.

Only reference I can see to your 4A0 260 805 AD is for V6 application on the Audi 80 - it has the Poly/Ribbed belt, not the V-belt that you would have on the (RHD) RS2.

We need to ask some other RS2 owners in UK and EU about this to get the facts !

On the face of it - your spare compressor will NOT fit.

Paul

[S2central.net]

Whoops - cross post there... Took me too long

If you have LHD RS2 then that one *might* be perfect - just look at the one thats fitted today - does it have V-belt or ribbed belt ?

The answer to that will clear up the confusion on manual vs digital as well.

Paul

[S2central.net]

AFAIK - the compressors on digital climate systems have some additional electrical connectivity into that wiring loom. This is kind of confirmed when you look at the untrustworthy pictures on the family album for example.

I think the errors on S2 & RS2 aircon pages are that the 5-cylinder pages do not portray (anywhere I can find) about manual or digital variants and it defaults to just showing the unit with V-belt for manual system. Thats the theory !

Get thee under your car Mr.Bowlerwell and inform the assembled Audicinados pronto

[S2central.net]

Yep - just found the aircon book... Definitely ribbed belt for that compressor. It should have two electrical connections -

1 - Magnetic Clutch (N25) - Input from controller to turn it on or off
2 - Compressor Speed Sender (G111) - comes from compressor to control unit

I've just remembered some other vague notion that the climate control module can be configured to run with or without the G111 input - which then would point at family album being correct in that the compressor with V-belt is OK. Uhhhhhh plot thickens. Hope you are under that car as I type here

Paul

[S2central.net]

OK - some knowledge from the good book of Audi OFRM then... Cross-checked with schematics on Audi S2/RS2 and V6 engines.

That G111 signal is only relevant to the ribbed belt used on V6 engines (But its ribbed on other Audi engines such as AAN).

The wiring for digital climate clearly shows usage of G111 on the V6, but NOT on the S2/RS2.

So in conclusion - that spare compressor you have will not work on your RS2 as it needs a V-belt setup.

Next step is to confirm if different digital aircon controllers (E87) are used on V6 models from the S2/RS2 or if it is something that can be tweaked by a h/w jumper or s/w setup if E87 is common.

Paul

[Bowlerwell]

But if I take the old pulley off the old compressor, and put it onto the replacement one, will that make it compatible?

JB

[S2central.net]

If that can be done, then yes that will work. No idea if the pulleys are interchangeable... They prolly have different clutch mechanisms - the connector *might* be different too. The G111 sender will be ignored of course, but leave it screwed in.

Oh and unless you know how much oil is in that compressor you really need to get the system drained and evacuated by an AC specialist so the right amount of oil and gas is added to it... Oh and change the filter/drier as well... And mybe the restrictor if you wanna be picky.

[S2central.net]

Oh the other caveat is that despite that compressor being used on the AAN engine - it doesn't mean you have the right mounting bracket for RS2. Definitely worth some close inspection before removing anything.

[S2central.net]

Mmmm well family album lists same controller (E87) for all R134a digital systems on Audi 80 - no mention of engine code variations. Its 8A0 820 043G - must be a setup on it to ignore G111 on the 5-cyl application.

The S4/S6 uses 4A0 820 043 M - dunno why that should be different - maybe non configurable ?

Dunno....