Mercedes Repair Questions? Ask a Mechanic for Answers ASAP
Hi, from what you have described it sounds very much like the V belt which drives the alternator, power steering pump, water pump etc has failed. Look at the front of the engine at the belt to see if it is intact or if it has broken/come off the pulleys. If this is the case then all of the pulleys on these components including all idler pulleys & belt tensioner should be checked for damage & replaced as required.
You should not drive the vehicle until this has been repaired as further damage could occur including engine damage as the water pump will not be working to cool the engine if this is the cause of failure.
Best regards, Paul