JerryCurl

I took over my 98 E320 from my brother, who always had the car serviced at the dealer.

About 1.5 years ago, I started changing my own oil, using Mobil 1. Since that time, I have noticed the motor is much dirtier and there is always oil gathering underneath on the skid plate. Before this, the motor was really clean. So I am beginning to suspect that maybe the car was only serviced with regular oil, and not Mobil 1.

Of course I've heard if you go from regular to synthetic - you will get leaks, which I think is happening.

Question is - what if I switch back to regular oil? Will the leaks stop, or am I stuck with the smell of burning oil (it's not like the stuff is pouring out, just enough to be irritating).

We can't find the service records and the stealer said it depends upon the owner and car, but they don't have the info.

Musikmann

It should be very easy for the dealer to determine what the car had in it when it was imported; I would use whatever that was. 1998 was the changeover year (some 98s had conventional, others had synthetic), and I went through this with an E430 I used to have.

I have also heard that if you switch to synthetic oil on an engine with a lot of miles that you can start using it. However, I think that is an old wife's tale. I smell burnt oil on occasion too, and it has always had Mobil 1 0W40 full synthetic in it. I don't think that is very unusual for MBs to emit that odor, but I would determine where your leak is exactly.

If your brother always had it dealer-serviced, they should have a complete history. They must be idiots, or have some other reason for not sharing the service records with you.

Good Luck!