Rx4Success

Hello All... I'm ABSOLUTELY New to this, but I'll give it a try. I have a 2007 S550 which has been wonderful until recently. It began making a humming sound accompanied by constant vibration throughout the car. I was told by the mechanic that the ABC was suspect and recommended flushing (nearly $600 USD, to NO avail). Service Advisor at dealer quickly cited accumulator, adding that it's a common problem... all during which, I've lost no pressure or shown any codes. Finally 2 days later, after a fill- up, I noticed what seemed to be like a slipping or hesitation upon acceleration and during shifting (automatic). Over the course of less than 20 miles it began to "neutralize" (ceases pulling while engine revs on acceleration) itself while in D(rive). After pulling over and shutting the car down, waiting a few moments and starting again, it would drive a little father before doing the same again. By the time the tow truck arrived, it would scarcely move feet before "slipping", but after the bouncy ride on the truck, the car would again shift normal at the shop. They flushed both ABC system and Transmission several times each, but 50 miles (same evening) after picking it up, it began to repeat the "slipping and revving". I would appreciate ANY information on same/similar circumstances and solutions. In advance, Thanks all for time and assistance.

Rx4Success

In addition, I'd also like (NEED) some useful information about GOOD aftermarket warranties that cover such...as I have recently crossed the 80K Mile mark..... Again, ANY assistance is GREATLY Appreciated! THANKS