synthetic oil a bad idea?
 

Hi Folks,

I'm brand new to this forum, but belong to others and am a gear-head. I just bought a '95 E320 wagon which just had the head gasket and wiring harness replaced (I've been doing my research...). The car has 186k miles and runs like a dream.

In everything else I own I run Amsoil. But reading through E320 threads I'v run across negative coments about synthetics. What is the best oil for this engine?

Thanks in advance,
Mike.

For 1997 and older, MB recommends an approved oil on the 229.3/229.5 sheet which includes mostly synthetics. At the least, they recommend an oil with API rating of SL or SJ.

There have always been 'warnings' about switching a car from petroleum based lubricants to synthetic ones with attendant horror stories. There were pretty much the same stories when detergent oils came along. You might be too young to remember that one. In my opinion, if a engine has been well maintained in the past, there's little risk.

I have done this more than 50 times in fleet and private engines. Zero issues, except for a few really badly worn motors that began to seep from the crankseal. (Poorly maintained engines with 150,000 plus miles.)

Sludge breaking loose and plugging to oil intake would be the main concern in a high-mile conversion. Have you heard of other issues?

Mercedes engines turn, wear and explode fuel to make power just like the rest of them. Built better than many, but no magic box. People also had bad things to say about radial tires, fuel injection, serpentine belts, coil packs vs old points distributors...I bet there are even a few hardcore people out there wishing for a return to leather in the springs...

I have seen several debates online about this subject. The problems are always speculation or: "I know a guy who knows a guy who said his cousin had xxxxxx issue one time..."

I will add one to your two...

An engine that literally has inches of sludge.
Out of all the motors I have done with my own hands, one of them plugged the screen, but we knew it was a 50 50 shot and we did it anyway.

The engine literally had only two and a half quarts of capacity, out of a 6 quart pan. The rest of the volume was hardened tar. (It was REAAAAALLLLLY bad)

Again, if you can see 1/2 inch of sludge on the rockers, you might want to add a quart with the rest dino and change it over slowly so things do not come loose too fast...then again, most engines like that are toast anyway.