M3 Compressor bracket mystery

[FEP]

Can anyone shed any light on this?

The bracket that holds my a/c compressor to the block had a crack in it.

Here it is.



It has no numbers or id on it at all and frankly looks a bit home-made.

When I looked on the ETK, there seems to be one a/c bracket for all E30's and not only is it nothing like mine, it features bushed mountings and fixings that run downwards into the top of the compressor - mine has lugs for bolts to run horizontally through, so it seemed like I have the wrong compressor, and that in the absence of bushed mountings, the vibey old s14 had cracked the bracket, (and the adjuster bracket and slightly cracked the casting of the compressor).

I had the bracket welded as a short term fix and resolved to try and sort the problem going forward.

Then I found this picture on S14.net, which clearly shows the same bracket just next to the alternator.

http://i978.photobucket.com/albums/ae26 ... rts011.jpg

I'm now assuming that its p/n 82 39 9 404 494, which is listed on bmwfans / realoem, but not pictured, as a retrofit part for a re-manufactured a/c compressor for any E30. BTW, I sent the guys at BMW Cheltenham the pic of my bracket and they said they'd never seen it before.

My compressor has this p/n on it: 6452 8 363 550.9 and a BMW propellor logo - I'm assuming that it is the re-manufactured item.

What I really don't understand is why BMW apparently went from a fully bushed mounting to a hard mount. If I leave it as it is I can't help thinking its just going to shake itself to destruction.

I don't even use the a/c anyway, but seem a shame to bin it as it's part of the spec of a very original car.

Anyone got any ideas.

Cheers

FEP

[bss325i]

Are your A/C pipes metal or rubber?

[FEP]

Are your A/C pipes metal or rubber?

Metal - or at least the bits that I can recall seeing are metal. Can't guarantee that their aren't some rubber bits somewhere.

[bss325i]

Any pics of the pipe work in the engine bay?

Also, is there a vent grill in front of the ash tray?

Does the A/C switch have a single button or twin?

[FEP]

Any pics of the pipe work in the engine bay?

Also, is there a vent grill in front of the ash tray?

Does the A/C switch have a single button or twin?

I don't have pics to hand, but I can of course take some.

Not seen a vent grill - is it obvious?

Blue a/c button with the snowflake and IIRC 'recirculation' button just below.

What's your line of thought?

[kam-325i]

line of thought is dealer fitted A/C

Bracket is deffo "Home Made".

[bss325i]

Yep, that was my train of though but all of your answers lead to it being a factory A/C installation not a dealer fit Deavia system.

[FEP]

line of thought is dealer fitted A/C

Bracket is deffo "Home Made".

So a guy in the states posts a photo of the identical part and its home made? Hmm!

My point is that the ETK does mention an alternative bracket even if it doesn't show any picture. Also, I'm using a BMW marked compressor - there ought to be a bracket that fits it don't you think?

[FEP]

To be fair - I just realized that I hadn't stated that the S14.net post was a USA post but it was.

[kam-325i]

i dont litterally mean "Home Made", but the same as in your opening post, it is not what you would expect from BMW, But something someone has knocked up to replace an original one.

it could be that the original BMW bracket had a flaw, and someone came up with this as a "better replacement".

[FEP]

i dont litterally mean "Home Made", but the same as in your opening post, it is not what you would expect from BMW, But something someone has knocked up to replace an original one.

it could be that the original BMW bracket had a flaw, and someone came up with this as a "better replacement".

Yes -its a bit curious. Strange that no-one seems to have any knowledge of the BMW part.

My bracket is also horribly heavy - and even that didn't stop it cracking.

[kam-325i]

Found this about the Bracket

"this is a common failure point on E30 M3's with upgraded suspension and stickey tires.

It's a shame that BMWCCA will not allow racers to remove this item that is prone to failure."

[FEP]

Found this about the Bracket

"this is a common failure point on E30 M3's with upgraded suspension and stickey tires.

It's a shame that BMWCCA will not allow racers to remove this item that is prone to failure."

If you look at the realoem page quoted, they seem to be referring to the standard bushed bracket. (Or at least the smaller steel plates on either side of the main aluminium bracket).

[Francisco]

Yep, that was my train of though but all of your answers lead to it being a factory A/C installation not a dealer fit Deavia system.

The bracket shown on the photo is a DIAVIA retrofit. I have one right here with me.

The rest of your description is from a factory A/C system. It's a mix of components (the compressor is specific for that bracket).

[bmwe30mtech]

That bracket was fitted to lots of M3s by BMW in the early 1990's. It was part of a upgrade kit used, in which R134a compatable compressors were fitted, with built in pressure switches. The cost for this upgrade was about £1700, and all the old compressor mountings (as shown on etk) were binned. There is very little information out there for this bracket, and as you say no part numbers. This becomes a problem because it is not bushed, and so the buzzy S14 constantly rips through the compressor adjusting bar, and when it snaps you can't just buy another one! You have to buy adjusting bars of similar length, but for example from a different BMW model.

As for the bracket I have not seen one broken before, and can only reccommend that you buy a complete new bracket set (I have the PN somewhere) or weld up up well, or revert back to original M3 air-con.

The bracket is not home made, and nothing to do with dealer/factory fit status of the air-con.

Paul

[Francisco]

That bracket was fitted to lots of M3s by BMW in the early 1990's. It was part of a upgrade kit used, in which R134a compatable compressors were fitted, with built in pressure switches. The cost for this upgrade was about £1700, and all the old compressor mountings (as shown on etk) were binned. There is very little information out there for this bracket, and as you say no part numbers. This becomes a problem because it is not bushed, and so the buzzy S14 constantly rips through the compressor adjusting bar, and when it snaps you can't just buy another one! You have to buy adjusting bars of similar length, but for example from a different BMW model.

As for the bracket I have not seen one broken before, and can only reccommend that you buy a complete new bracket set (I have the PN somewhere) or weld up up well, or revert back to original M3 air-con.

The bracket is not home made, and nothing to do with dealer/factory fit status of the air-con.

Paul

Didn't know that, all 3 I've seen (a sport evo and 2 regular M3's) came on retrofit A/C systems. I got one of those brackets here next to the specific compressor, rad, hoses, etc. I removed from one of these to fit a factory unit.

[FEP]

Thanks Paul for the info.

Seems that BMW really did let their engineering standards slip here.

Do I want to shell out £££ for an original compressor + brackets + re-gassing etc for an a/c system that's probably of limited real world use?

Think I might rip the whole lot out and save a fair few KG's.

[pacerpete]

E30 M3s with A/C are a constant cause of woe. My ideal M3 would not have A/C, even if I lived in a climate where it was of benefit for more than two weeks of the year.