I'm considering a purchase of a w116 that I probably shouldn't be messing with. But the combination of a gambler's price and excellent body/interior condition are making me think twice.

The car starts quickly but runs very rough (as if misfiring) and smokes like it has a sponsorship from Phillip Morris. It has enough power to tool around a parking lot, but I didn't dare get it on the road. Its current owner (and my locale in general) favors American cars and has no use for a "furrin' jobber."

He says it was a daily driver until it started showing minor signs of missing (vibration, rough idle, etc.) He took it in for a compression check (probably to a "furrin'" hatin' mechanic) and found one cyl testing just slightly low. When he got it back from the mechanic it was running as it is now, and he gave up. He suspects the mechanic may have misconnected the spark cables or injector wiring, but that sounds like too simple a solution.

For the price he's asking, I can afford to spend a few thousand with a (trusted) local MB wrencher to get the car on the road. But I've heard that these '70s 8's can be pricey to fix when things start going bad.

It's a tough call. The body and interior show that the car has been extremely well cared for through the years, and the seller assured me there are no bottom-end problems (for what that's worth). My inclination is to walk away, but from what I've been reading in this forum it could be something as simple as a stuck injector. I'd even be happy if it required "only" a valve job, but I can't afford to get into a rebuild.

Your thoughts?