R320 CDI loses power on snowy highway.
 

Hi,
My wife was driving our diesel R from CT to Boston in today's blizzard. It was running fine on the highway one minute and the next it is slowing down despite pressing the pedal almost to the floor. We pulled over and idled for a while. When we press the throttle in park, it wouldnt go over 3k. It is shifting ok. Any thoughts before I take it to the dealer? No CEL. Your opinions are appreciated. Thanks

I think that the fuel is starting to gel. You are having some nasty weather up there. Try putting some anti gel in the tank. If you park it inside for the night, I bet that it would run fine until things start to freeze again.
Mike T.

Sorry to be Capt. Obvious but are you sure the loss of power wasn't because of the traction issues or slipping? You did mention it was a snowy highway. Also, not sure about the R class but I know my car has a rev limiter in park.. Does the R320?

If the traction was engaging, then there would be a light flashing on the dash and there would be a noise too. Since nothing was mentioned, I'll go with diesel fuel gelling.

I too got bad fuel one winter day, pulled off, put the Power Service Anti Gel in the tank, and I was fine by the time I got back to the highway.

MB will never recommend using anti-gel, but I don't trust fuel stations to have my best interests in mind.

Thanks guys for your thoughts. There was no lights and traction control was not kicking in. I didn't think it was gelling since I drove it through Canada and MI a month ago while temp was in the early teens and diesel didn't gel. But you never know the composition of the current batch in the tank. I was wondering if it is the fuel pump in the tank, not pumping enough fuel for the highpressure pump. But now it's in the heated garage. Let's see what today brings. Thanks again !

cloged air filter?

Air filter was changed 2k miles ago. It started and revved without issues yesterday. Today I am going to drive it and see if the problem comes back.

may be the transmission liquid needs to be changed or checj the transmission mount once. do some engine related troubleshooting, if nothing works then take it to a good dealer.

I had same issue and problem was in air filter. Snowdust glogged airfilter and "breathing" become hard. I cleaned filter and filterbox from snow and everything works well. It happened for me several times. Specially when i have driven behind of some trucks, who bring up from road this "snowdust".