Once a serpentine belt breaks on a 2003 S-500, is it absolutely necessary to replace the pullies, air compressor, etc. or just the belt? What is a reason price for just replacing all involved parts?
What kind of damage happened to required all of that to be replaced?
Not necessary unless they were damaged, but then again idler pulleys and belt-tensioner pulleys are cheap and easy to replace, so why not when you have it all apart? Question is what caused the belt to break? How many miles on it?
About 90K miles. Last week, air suddenly stopped cooling. Then after a few more miles, we lost power steering and the battery light came on. We immediately pulled over and had the car towed to a shop we've dealt with before. The mechanic is saying that in order to warranty the belt, he needs to replace all the parts. He did suspect that one of the pullies malfunctioned which caused the belt to break. However, how would you know just by looking at it that air compressor, etc. need to be replaced? I would hate to spend the value of the car trying to repair it. He is working up an itemized estimate. My husband is trying to work with the mechanic but I'm just trying to get a second opinion. Basically I want to repair ONLY what is necessary. Contemplating selling the car.
Based on your description, sounds like a bearing or pulley failed/locked up. Adding a new belt won't fix the issue. A good mechanic can diagnose a bad pulley. You can do so by spinning it or if it makes any noises. Your mechanic is being proactive and replacing all worn parts so you don't have to tow the car anytime soon. At 90K, German cars should get all the pulleys swapped out and a new tensioner as preventative maintenance. Price all comes down to what is replaced and labor rate, it can vary. Driving an S class MB requires upkeep and a large bank account.
From your description, it sounds like the AC compressor failed first, if the clutch froze it eventually caused the belt to fail. They can test the AC compressor to see if it spins at least. When replacing a belt it is good practice to replace idler and tensioner too. The only other pulleys to check would be alternator and power steering, you shouldn't have to replace those unless they are also bad, but your mechanic should be able to tell. Let him replace the belt, idler, tensioner, and if needed AC compressor. It'll cost more, it is a Mercedes after all.
I had a similar problem, it should be around $700-1000 max.
Looking for a Used S-Class in your area?
CarGurus has 6,628 nationwide S-Class listings starting at $2,900.
Search Mercedes-Benz S-Class Questions
Mercedes-Benz S-Class Experts