bsamini

Hello All -- I'm new to the forum (and new to the S550). I was a BMW 7 owner (and longtime BMW customer). One week with this S550 -- and I am totally sold. What a fantastic car.

Anyway -- on to the question. I picked up a 2007 S550 with a sport package with 55K miles. The car is very clean and everything looks good.

Drives great as well -- except that I noticed a very high pitched engine noise (sounds like its coming from the front left side). You can hear it at low speeds around 2500 RPM. I get the noise accelerating and decelerating.

Planning on taking it to the dealer next week -- but wanted to see if anyone else has experienced anything like this.

Thanks.

softgenious

Tire noise? Could be normal depending on what tires you are running.

bsamini

softgenious -- Thanks for the input. I ruled out tire noise -- because I get the engine noise (or at least what I believe to be engine noise) when the car is in Park and I rev the engine.

steveb9771

Might be a faulty pulley.

S-B-13.22/01d JUL08 Up to engine #272xxx 30 476520 RPM dependant grinding, howling, whining or high pitch whistle noise coming from the front section of engine, the upper idler pulley will be replaced.

Service Campaign 2008070002 AUG08 – 164, 164.8, 171, 203, 209, 211, 216, 219, 221, 230, and 251 Dealer will replace the existing V-belt upper guide pulley with one that is optimized for noise reduction (guide pulley – part #A272202101905). Approximately 192,941 vehicles affected.

See https://mbworld.org/forums/new-s-cla...ns-date-3.html

Red Marko

steveb9771 is most likely right.
From the description you gave us it is a pulley.
I also remember almost the same thing on my RIP S430.
Easy (dealer) fix.
Anyway, let us know what it was.

trumpet1

Lift open the hood and have someone rev the engine a few times for you while you try to pinpoint the sound source. I had the pulley problem too but only after about 18000 miles. Also make sure someone didn't mischieviously stuff something in the engine air intake tubing or a leaf or something could be in the air intake duct work. You never know.

Has it been this way from day one???

bsamini

All -- Thanks for the helpful input. I will be dropping it off this week to the dealer. I will post as soon as I have it back.

From the sound it makes -- I would not be surprised if it were the belt/pulley issue.

Thanks.

softgenious

Had mine replaced and I would bet that is your problem. I forgot about that...

bsamini

Mystery Solved -- picked the car up last night and here is what they came up with.

The Hydraulic Accumulator/Shock Absorbing Unit mounted on top of the Active Body Control Unit went bad. Cost to replace -- $1,100. I guess it could have been worse. Good news was that otherwise -- they said the car was is good condition.

I was hoping it was the pulley/belt issue -- but no luck.

Anyway -- thanks to everyone for the helpful input.