I bought a 1985 500 SEL. Beautiful black. Bought it Thursday. It has been driving fine. Small puddles of oil and tranny fluid on the floor.

The previous owner recently replaced the tranny with a used one.

I have put about 200 miles on it. Tonight, on the way home from work, and on the expressway at 60, The front end start shaking violently. I knew I had a bad tire, so I thought the tire blew out. I coasted off to the side, as the engine died. The car would not re-start. The tires are fine. The oil is still golden in color. Removing the valve cover cap, the cam shaft visibly turns fine. The tranny fluid is red and fine. No silver. The radiator fluid is fine and still green, with no milky residue. No fuses seem to be blown. The engine turns over fine. Not too easy, not too strained. I could not tell if it was getting gas, because it is a 5 litre engine, and has a big flap on the carberator. I pushed down on the flap and tried to peer into the carberator, but I saw no gas with a crank-over. Perhaps the gas squirts under the second flap which is the butterfly one?

Any ideas?