Help...
 

'86 300E, 91,000

After driving only a few minutes yesterday, I noticed what sounded like a loud ticking noise from the engine that quickly went away. A minute or so later at a stop light, it happened again. I decided to pull over an check it out. Just as I pulled over, the ticking quickly turned into a clunking sound. I shut the engine down and popped the hood. Belt and pulleys all seemed fine, there was no smoke or unusual smells, the oil level was right where it should be... so I started it up. A terribly loud clanging and clunking sound got even louder. I called a tow service and got the car towed to a mechanic. Unfortunately, they are closed for the weekend and I am left trying to figure out what happened.

Could the oil pump have stopped working??
Did a main bearing freeze up??
Is my engine fried??
Where do I start??

This is my 3rd Benz(both of my previous cars went over 200k with no major engine work needed. This car is (was) in great shape and has been a great service history. After driving 3,000 miles, the engine oil is still very clean. I can't imagine what could have happened.

Any advice would be greatly appreciated!

Thanks,
Paul

Obviously, it could be one of many possibilities, but with that milage on that engine (given reasonable oil change and maintainance schedule) the pulleys/pulley bearings/tension(er) scenario would seem most likely; not engine. Was A/C on when this occurred(compressor)? Did you notice that oil pressure was up? Water pump not leaking/eccentric? Lower end problems are the most rare, so I'd put that at the end of the list, personally. FWIW

Paul,

Sounds a little scary. Do you recall where, front or back, driver's or passenger side of the engine the noise was coming from? Did it seem to get louder and clunkier as the engine slowed, seeming to be tied to engine speed?

These things can be hard to understand when you are there, in person, and from the other side of an internet connection it is even more difficult.

I agree with jbaj007 that it sounds like an accessory drive from your description, than an internal engine issue. Did you check the single, serpentine drive belt and the pulleys it is wound around? If one has come loose or the bearings are shot, it might make a clunking noise.

Good luck, Jim