bigchingan

Heres the deal: I have an 84 300SD, 222K, original trans, some wear and tear such as rust spots developing (small tho) on the two front doors near the center molding at the front of the door. Also a leaking trunk, and just had to replace a rear control arm due to it being completely rusted through. My dad has gained possession of an 85 500 SEL with 227K. Its mine as long as I'm willing to spend some time helping replace the trans and AC compressor. The downsides to the car are the following: 227 K miles on a non diesel engine (I don't know much about the reliability of the gas models compared to my diesel), need to replace trans, ac compressor; the dash has severe cracks compared to mine, but the wood is basically in the exact same condition (bowing up in the center behind the steering column, missing the piece over the passenger side vent on the side) but it is of the burl walnut variety instead of whatever standard fare i seem to have. There isn't any rust on the doors, but there is some on the back (I can't remember if it was on the trunk lid or below, I'll check it out again soon); the hood is dented in. Overall, if the cars were new, it'd be a big step up with features such as all four seats being heated, power headrests, longer, much faster, working alarm. I could trade trunk lids, and hoods with my current car (not sure about the trans or AC tho). What do you all think?

w123_w126

Some would say you’re crazy to move from an OM617 to an M117 – not that the M117 is a bad engine but that the OM617 is so bullet proof and easy to work on. My M117 has the same miles and it runs great, the Mercedes V8 is very strong provided the oil is changed on a regular basis. As you can see I own a 500 SEL and I love it: there’s nothing like a Mercedes V8, the car is very quick and powerful. But my car was well maintained by previous owners, if you don’t know the service history of the car I’d be cautious.

The plastic guides on the M116/117 are a problem point only if left in the engine too long, they have little tolerance for being neglected. The T chain and plastic guides must be replaced every 100,000 miles to avoid engine damage. The M116/117s can also develop valve train issues if not properly oiled – wear would show at these miles with too much noise from the valve covers. In fact, the area around the valve covers s/b quiet.

Your 500 SEL will use more fuel then your SD, need more maintenance, and be subject to the various problems associated with the Bosch KE Jetronic fueling system such as high or rough idle and stalling problems brought on by age and miles. For example, the engine you are considering will more than likely need to have the injectors replaced, they wear out by now – the injector seals may also need to be replaced and she my have also developed some vacuum leaks.

If you’re willing to do the restoration and keep up with the maintenance issues, your 500 SEL will be a fast, beautiful classic. And my 500 SEL has proven to be very reliable over the years.

Good luck