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'89 E300, '06 B200, '15 VW Tiguan
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Discussion Starter #1 (Edited)
our B is now at 200k and is making more and more of a whiny noise. Thought it was the CVT but I've heard that whine before on other non-CVT cars. Sure enough, dealer tells me its the whine a 'Wobble Plate' :confused: a/c compressor makes. Of course the compressor can't be turned off.... that's the whole point of the 'wobble' :D I guess. I'm guessing it'll be close to $2500 k to repair completely when and if the noise gets to be unbearable. Hope this helps in any decision making you may be in the midst of.
 

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Our compressor and what the dealer described as a clutch (I know there is no A/C clutch) was replaced under extended warranty at about 100K km. It was growling more than whining, but now the whole assembly is silent. It was noisy from about 20K km.
 

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W123 '83 200, W210 '98 E200K, W212 '13 E350
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Not 100% sure our compressors have a clutch, but they should since I doubt they're different from other cars.

It's an electro magnet clutch though (can't think of a better name). Basically when the computer needs the compressor to turn, 12V go to the coil and grounds through the body of the compressor. This causes a tiny space between a plate (attached to the compressor shaft IIRC) to close against the pulley (which is always turning while the engine is on through the serpentine belt), and the compressor spins. When current is removed, the clutch let's go and the pulley and plate separate and the compressor comes to rest.

Never heard of the wobble plate term (I'm not a mechanic that's my excuse) lol! On to google...

edit: wobble plate (more correctly swash plate, but I'm sure there's another term I'm more familiar with) is the kind of compressor...the one linked below shows the clutch assembly on the pulley end - video mentions clutch workings:

 

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It's a variable compressor that does not click on or off, but I'm not sure how they work. I've had cars before with conventional electromagnetic clutches for A/C but this is not one.
 

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Lol, didn't know that. Why do they always have to eff around and try new things with our B's (and a few other cars). I have a feeling this is another case of a cost vs. reliability trade.

edit: found some info, but it's A-Class...Mike are you sure? What's your source? My link also shows info about a bearing going on the compressor pulley side, which may be the noise some have mentioned.

http://www.aclassinfo.co.uk/mypage.31.htm
 

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I was getting some additional noise, but it turned out to be a loose heat shield that was making noise at idle with the compressor on. I'm going to have to get my system check for a leak, after getting the a/c refilled for a second year in a row, they added a dye. Same thing as last year, a/c putting out mildly cool air when it's >+25C out but with a refill it's nice and cold.

Anthony
 

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'89 E300, '06 B200, '15 VW Tiguan
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Discussion Starter #7
FWIW, there is apparently no short belt available to bypass the a/c compressor.... hmmmm :mad:
 

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I've had the A/C on my 2007 charged twice now under the extended warranty (which ran out two weeks ago...). Last summer and this summer at the 60K service. Both times the invoices indicate "install a/c dye, tighten service values, charge .85kg 134a". Apparently a certain amount of leakage from these service valves is normal although I think that's a pile of something starting with an "s". I can believe that hoses and seals leak (which then require replacement) but a "service value"? Just one more quaint aspect of these cars I suppose...
 

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I know that R134A is a smaller molecule than R12 was, but the A/C in my old 1989 Peugeot 405 worked perfectly to well over 300,000 km - then it died - but by then it was 18 years old and we were getting the B so it didn't matter. The B A/C in our car seems OK, though the compressor was replaced last year, so it's got a virtually new refrigerant charge.

I don't think ANY leakage should be normal, but even high end Japanese cars have that problem.....
 

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'89 E300, '06 B200, '15 VW Tiguan
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Discussion Starter #11

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2006 B 200 .....& Audi A6..
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My 85 Camry had the AC working perfectly with over 23 years of operation on it when I sold it...so there you go.........

The Canadian B had AC as an option way back when and some reportedly came without it,...so maybe there is a way to by-pass it. Can't believe everything that our stealers tell us.

Changing the belt is a PITA as reported by others,..but within a tight space and therefore tricky and access can be a problem,.. so it's probably better to fix the whine instead.
 
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