Tensioner failure E300TD
 

Has anybody experienced a sudden tensioner failure leaving the serpentine belt flopping around? The car is my '99 E300 TD and I wouldn't have known except for the 'battery charge' warning light which came on when the belt started flopping. Can this cause any damage by driving a few miles like that?

It could, because the water pump won't circulate. Likely not, though. The belt tensioner will fail this way because the tension 'spring' is actually a molded-on rubber bushing that is twisted. When the rubber deteriorates, it breaks loose, and the assembly must be replaced. Don't drive until it is fixed.

Steve

make sure your mechanic replaces the entire unit as well as the adjuster....Good Luck ...we've all been there.

Do the shock while you're at it.