I have the weirdest problem.

My car "shudders" as I slow down to a stop, not all the time, but probably 2/3 of the time. It happens whether I slow down quickly or slowly, and from any reasonable speed (over 10mph). It does NOT do it from neutral so I assume it's engine related rather than brake-related. Furthermore, it doesn't do it while accelerating, only decelerating.

As a further point of information, the engine is not 100% smooth, it's got 116,000 miles on it and when I'm idling, every few minutes there will be a little dip of the tachometer and a little sound as if the car had one tiny hiccup.

Four MB specialist mechanics have not been able to solve the problem, and the dealer said that they saw this problem once and spent $8,000 and didn't fix it. Hopefully someone here has better advice

 

Well it's been a while since made your post. Have you solved the vibration problem yet? If it was the same problem mine had, it would have only gotten worse and quickly. My 300SL began to have a slight vibration felt in the front end and only when coasting at certain speeds. It gradually got worse until it became the worst sound and feel you could imagine in your baby! I knew what it was by that time but was only trying to the car into get it fixed. The vibration started out very minor but then it became like driving on a grooved center line or shoulder. A very distinctive feel, but only at specific speeds and only without acceleration. Thought my tranny was destroyed or something. Turned out to be the drive shaft flex joint, which connects the tranny to the driveshaft. Parts can range from $36 to over $400 for the same part so if you need one check around. The cars have 2, one front one rear but my rear one was perfect. I will try to post the pics we took. After replacing this part, my car drives beautifully and my transmission now shifts very smoothly. And it was a pretty easy fix.

Can't really help with the dipping oil pressure/hiccough problem though.

Let us know what you have learned.

 

If the "shudder" is accompanied by what I call a "surge", it's likely to be throttle body.