STLcoupe

Hi forum!

I have a 2002 C-230 Coupe that's giving me fits as I enter my 12th year of ownership.

Currently, it's throwing two CEL codes.

• P101 MAF
• P446 Emissions

I'm well familiar with the dreaded 446 emissions code & am ignoring it. Currently also ignoring the MAF code until I decide how long I'm going to keep the car.

However, lately I've had a strange occurrence. While driving I sometimes get a vibration in the rear wheels that feels like the wheels are spinning at different speeds.

It's a low hum as if one tire is perhaps skidding rather than turning as fast at the other.

It happens without fail while driving uphill.

What could this be? I've hypothesized:

? Wheel bearing?
? Something related to the MAF sensor?
? Transmission starting to go?
? Torque converter?


I know the car very well at this point, but am totally stuck here. Help! Thanks!

KSKarl

Your description sounds like wheel bearing to me.

C230 Sport Coup

Check the oil in the diff ?
Trans fluid/ oil ?

I had noisy tires at one point that sounded the whole drivetrain was shot.
And my GF's ML had bearings in the front diff that made a horrible sound...(since replaced)
is your C 4wd ? Oh never mind...it's a C Coupe...

jarvace

Have you checked the Driveshaft flex disks? I was getting strange vibrations and they ended up having splits all over them. They are hard to see until you have the disk in your hand and you flex it with some screw drivers.

Just replaced the originals which has 185000kms on them. It also improved the gear shifting of the car, I imagine because the rubber has more give in it.

C230 Sport Coup

Fuel filter full of crap, and moving around while driving?
Gets clogged when going up hill?