It's Not My Clutch After All! A/C Compressor... - BMW Forum

Eric S. · 06-28-2006, 10:48 PM

After deciding I had a clutch or catalytic or heat shield rattle, I finally got the front of the car up on ramps this PM and pulled off the splash shield and had a look around. With the hood open, the sound seemed to come from the front passenger side of the engine compt. From underneath, the rattle appears to be coming from my A/C compressor. My paper towel tube-to-the-ear test confirmed it, but I really need to get a stethescope.

Since I just replaced the tensioner and idler my first thought was something came loose, but I checked and all bolts are tight. I undid the belt and checked the idler and it spins silently, but when it's all hooked up and the engine is running, the tensioner is bouncing up and down and awful lot.

Meanwhile my AC mercifully blows cold. So what to do? Let it go? What needs to be replaced, just the AC clutch? Cost estimate?

PS - A search revealed that others have reported rattling A/C compressors that functioned OK, and in many cases it turned out to be a bad tensioner. Since I just replaced all of my tensioners, my A/C tensioner is brand new and seems to be functioning well enough, but if it is defective and making the noise, it would explain the noise beginning soon (within a week or two) after I installed the new idlers and tensioners (the idler spins quietly, BTW).

Comments? Help? Tips? Bueller? Bueller? I guess I can always try re-installing the old tensioner to see if the new tensioner is the problem...

hpacc · 03-05-2007, 03:05 PM

what ever happened with this? I'm having the same problem. Should I/ can I replace only the clutch... or do I have to do the whole compressor?!?! AC is working fine. AC Clutch skips and rattles and makes a horrible noise, worst when I hit high rpms. Thanks in advance!

Teh Prof · 03-05-2007, 03:24 PM

Hmm, well I can assure you the car doesn't make that noise any more...but what Eric did with it, I dunno...

LOS · 03-05-2007, 04:07 PM

I thought he said he ended up getting a new compressor!
Found it!

http://www.bimmerwerkz.com/forum/5-s...xed-47974.html

http://www.bimmerwerkz.com/forum/5-s...are-47751.html

LOS

Eric S. · 03-05-2007, 07:35 PM

For your E-Z reference, I ended up replacing the A/C compressor. Local Indie wanted $1600, but dealer did the job for $1375 thanks to my BMW CCA discount.

Yes, my A/C worked fine - it was just that awful noise. Well guess what, I found (through another thread here on bimmerwerkz) that the AC rattle is really the "death rattle" and, if left untreated, the AC compressor can eventually "blow", taking out multiple other AC components with it. It has something to do with the "reed valves". The other poster here sufference a nearly $4000 repair of the catastrophic failure of his AC system after he ignored the rattle.

There is no set time after rattle onset before "she blows", but I felt it better to spend $1375 now than $4000 later.

PS - This was the next-to-last straw for me, because my expensive water-cooled alternator went bad 3 weeks after I got the AC fixed. I'd had enough by that point (about 129,000 miles).

Eric S. · 03-05-2007, 07:41 PM

Quote:

Originally Posted by LOS

I thought he said he ended up getting a new compressor!
Found it!

http://www.bimmerwerkz.com/forum/5-s...xed-47974.html

http://www.bimmerwerkz.com/forum/5-s...are-47751.html

LOS

Thanks for dishing the assist, LOS! I miss you guys!

PS - A co-worker today told me he wants to buy either a 2003-ish Mercedes C-Class or a 2003-ish BMW 3-series (325). I talked him into not just the E46, but the 330i in lieu of the 325. Hopefully he can find one in his price range. I think he'll do fine now that he knows what to get...