BMW e53 3.0L A/C Compressor/System Difference
 

So I thought I would be clever and replace this POS variable displacement AC compressor on my 06 with a Denso unit which is used from 2000-2003, where it had what i would call a 'normal' compressor. I also bought the suction line required.

Is this as simple as I originally thought? Just replace the compressor and line with a pre-LCI unit and it will function as intended? Or is there more to the story??

I have heard of people doing exactly that, but have not seen a write up on xo


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I haven't done it, in fact I just learned that my 2 E53's have a variable displacement AC compressor from your post. I now see the problems that often come with it. However, I have read up on it, and it seems the variable displacement is purely mechanical, not electrical, so it seems replacing it with a fixed displacement unit like the Denso is straightforward and won't, in theory, interfere with operation (It may be a little louder and increase fuel consumption slightly)

Here is a link that might be helpful:

https://axleaddict.com/auto-repair/vdcadjustorconvert

In addition to endorsing the installation of a replacement fixed displacement compressor, this article demonstrates how to adjust the variable displacement (vd) valve and how to convert a variable displacement compressor to fixed displacement by modifying the vd valve if the valve is accessible.

EDIT: We should probably figure out whether the E53 Variable displacement compressor is externally or Internally controlled. It seems to me that the internally controlled unit would be more easily swapped for a fixed displacement compressor.

You will do us all a favor if you document your results from switching. You can always switch it back.

If the existing compressor has a magnetic clutch, I don't see any problem with replacing the variable compressor with a fixed compressor. If your existing compressor don't have a magnetic clutch there's no way to automatically cycle the compressor so that the evaporator coils doesn't freeze other other than manually shutting the ac system and turning it back on.

Thanks all for the feedback so far. I'm pretty sure the compressor is internally controlled but I don't know that for sure. I'm hoping someone has already done this successfully so I don't have to be the guinea pig.


I will definitely document my swap when i get around to exchanging it, probably won't be any time too soon though, unfortunately.

I don't see any problems with VD Ac Compressor.

- My 1998 528i Denso (it was a VD compressor from factory) lasted until 160K when it made noise, so I replaced it with another Denso ($220 for parts). Id di it myself and I am now at 180K, zero issues.

- My 2006 X5 3.0i with 135K, the Calsonic Kansei compressor is still fine. If and whenever I need to replace it, I'd stick with whatever came with the car, in this case, Calsonic Kansei brand name. However, browsing FCPEuro website, all I see are Nissens (which is probably OK) and BMW Genuine brand.

- What is the odometer reading in your X5?
- What are the symptoms?

BTW, I wrote a DIY for my 1998 528i AC Compressor below:

https://www.bimmerfest.com/forums/sh...d.php?t=924320

No problems until your VD compressor takes 5-10 min to start cooling. Otherwise it's just as great as a standard compressor. :thumbup:
Truth be told, I picked up this compressor and OEM line for a tad over $100. Other no name compressors for my year model were the same price, and i prefer OE brands where I can. The OE was something stupid like $300-$800.. No way man.



Nice DIY. Pretty sure the 98 e39 compressor is not a VD.
I am no mechanic but have all necessary tools to do everything including vacuum pump and gauges.

The X5 has just under 180k miles.
Symptoms are the typical e53 VD compressor symptoms. Works great when it works. Takes ~5min+ for the compressor to start working. If you rev the engine to 3-5k rpms, it typically starts working normally. Once it starts working, it works properly the whole trip. Pressures are normal, aux fan works, no codes or other symptims. No marbles in a can noises or any other noises. When you unplug the pressure switch, the fan kicks on high.

I first learned about a VD conpressor when i had my gauges on my 06 X5, AC on, clutch engaged, but no change in pressures, either from suction or pressure side. And i could see the clutch engaged. Aux fan also not running. But I could command the fan on via INPA, and fan worked with the pressure switch unplugged. And i knew my AC worked. This is what made me go to my trusty Google friend and learn about variable displacement compressors.

There is some detail about shim and air gap and magnetic clutch. Ac compressor clutch sometime can be refurbished.

Zombie thread! I'm having the VD problems and want to replace the compressor. What did you end up doing?