Car has been stalling at highway speeds and hesitating to start. In looking through the forums I found that oil could short out the wiring harness and cause some weird behavior. So I surmised that the massive oil leak after my last oil change might be causing the stalling.

Turns out I've been mis-using the rubber o-ring that comes with the oil filter. There is an o-ring groove in the screw-off filter cap. All along I had thought the o-ring got sandwiched between the bottom of the lip on the cap and the top lip of the metal filter housing and when I tightened the cap the o-ring just squeezed out of the way. Once I removed the old o-ring from the groove and put a new one in the leak stopped. Unfortunately the old black o-ring looked like it was part of the cap. I'd had the same o-ring since I bought the car in 2005. The o-ring actually gets sandwiched between the two cylinders formed by the cap and the housing.

Conclusion:Next time I won'tbe so quick to cuss the MB designers. Now we'll see if it continues to stall at highway speed.

 

One thing that might help you and others changing their own oil and filter would be to put a drop of oil (clean) on
the new O-rings before you put them on the filter holder and also the bigger one on the cap. Makes it easier to put
on and less chance of damage to the O-ring on the cap when you screw the cap back on the filter housing. Also helps
seal as well, just like putting a drop of new, clean oil on a "traditional" V-8 oil filter to help the seal.

 

Thanks for that Mrcoyote.

My stalling and hard starting continued. Local shop ran the codes and found none. Suggested that replacing the crankshaft position sensor usually was the culprit if there were no codes stored. So I spent a Saturday replacing the CPS. The old one did have a crack in the insulation and the fact that it was getting a lot of hot oil dripping on it leads me to believe that it was indeed the CPS that was causing the problem. Keeping my fingers crossed.

 

Good luck with the Fix!!

NeV