95 C220 harmonic balancer
 

ugh, I believe the tensioner pulley has come loose inside the engine
cover, and is clanking around. I can see the fan wobbling and it sounds
awful. We have been driving it like this for a bit, but only this weekend
has it gotten worse. Is it safe to drive 4 miles to the mechanic in the
morning, or should I have it towed? Taking it to my independent mechanic.
Any clues on how much it might be to fix?

Scott,
The harmonic balancer on your engine is part of the crankshaft pulley.
Are you saying that the fan is loose and wobbling about,if so I would not start the engine let alone drive it until it has been examined and repaired.
Really have no idea on cost without seeing the car or from the information you have given.
Good luck , Geo.

Check with the service campaign #2005-020003 there was a recall on the harmonic balancer I don't know if your model is covered I have a '99 E-320 and I received a letter took my car to the dealer and it was replaced free of charge. You should check with the dealer if its covered under the recall

i called the dealer and explained the problem. It did stall on my wife
tonight while she was driving it. The service didn't mention anything
about a recall. My independent guy uses OEM parts, I think I will have
it towed there in the morning vs the dealer.

update
 

Whew, just the waterpump. $300 later, good to go. Just curious,
but what is the general lifespan of these cars? Ours is 11yo, BUT,
damn thing still looks and drives like a new car. WE had considered
trading it for a new Jetta to have a warranty, but my wife doesn't
want to give this gal up. She loves driving a Benz.

Scott ,
These cars were the last of the Mercs to be built to a proper standard, there are no corrosion issues with the bodywork , the engines are bulletproof so long as they are serviced regularly , change the engine oil and filter every 6000miles using semi synthetic oil and change the autobox fluid and filter every 40,000mls (have it changed if you don't know when it was last done).
Routine servicing is easy and most things are readily accessible.
Mine is smooth and a pleasure to drive , the only thing I have changed is to put on Bilstein shocks as I found the ride a bit soft on our roads , but that is probably a European thing .
Enjoy your C220,
Cheers Geo.

Truly...

Motors MB in my opinion love oil 5w50 (Mobil) :y

Thanks guys! we have been doing about every 5K using MB filters
and high grade Dino oil. Since it is my wife's car, she puts few miles on it (work is 2 miles away). I know it had the 30K service done, not sure
about the trans oil.