RProsser

Hey all. I’d appreciate it if you could take a sec and listen under the hood of my 2005 SL55 AMG with 63,000 miles. Note: this is after the engine is warm and is not at cold startup.

You Tube

To me, it sounds like a bearing of some sort down low on the passenger’s side of the engine. In the 4 years/15,000 miles I have owned the car, that sound has always been there. I am the second owner, and the previous owner always had it serviced at the Mercedes dealer for every little thing. When I visit an independent shop or local Mercedes service center, not one service writer or mechanic has ever mentioned it ... so I assume it’s normal?

Since I've owned the car, I/or a shop have replaced the following parts that might relate in some manner:

• All belts, tensioners and idler pulleys
• Alternator
• ABC pump and reservoir
• Supercharger pulley bearing (Nachi Heavy Duty Bearing 45BG07S5A1G-2DL)

Even though I have heard this sound on other YouTube videos, it doesn’t sound right to me. It’s as though something is failing so any input would be much appreciated!

Thanks,
Bob

Das Geld 2

I def. do not have that noise(listened with headphones)

if you had it for 4 years and it hasn’t blown up you might be good.

im sure someone can chip in here who has seen it

RProsser

Thanks. Yeah it seems stable but it ain't right. Took it to a MBZ guru today in Newport Beach. After study, he said it's the AC bearing. Gonna put a re-manufacured AC unit in it. Given what must come off to replace the bearing -or- AC unit, might as well do it all.

pmercury

iTrader: (2)

you can check that easy yourself
just take a hard wood stick like from a broom or a empty pipe
for the stick, touch the devices or places you suspect
for the pipe hold it close to
other side on your ear

if you don't have a mic

seven_out

It would be interesting to me to know how he determined that -- whether it was by technique or just through years of experience. I would have suggested that you let the engine idle with the supercharger belt removed, and if need for further testing, then run the engine with the main serpentine belt removed (for just a very brief period of time, naturally).

okbarnett

yea, sounded like a pulley, or comp or pump
you can get a auto stethoscope with long probe and listen to that kind of noises

RProsser

I just saw this old post of mine. For anyone looking into the same issue, turned out (for me at least) that whining sound was the AC compressor. Replaced it and all's well

asabo423

Thank you for the update

tonylinc

That dual idler pulley, what did that cost you to replace, when I replaced mine they were about $700 from Mercedes just for that one part. Then replaced the other pulleys at the same time and the belts still were tracking funny. Turned out the crank pulley was worn, those have a molded rubber piece inside because they run two belts and after 90K miles and 20 years it had deformed. The crank pulley also costs about $700 from MBZ. I shopped long and hard LoL and got a genuine part, online for $495. My engineer mechanics had a friend who got them a dual pulley, genuine new MBZ part, for $300. Not cheap cars! With all that new again, no worries though.

tonylinc