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2008 E350 Wagon, 67K miles. Hi all - I had the air conditioning compressor replaced last week. Immediately after picking the car up I heard a slight squeaking noise....30 minutes later on the NJ turnpike, the serpentine belt broke, and the car lost power steering, cooling system, etc. I had the car towed back to the servicing dealer....they claim that the idler pulley went bad, thus causing the serpentine belt to break. My concern is, the car NEVER showed a sign of a bad pulley or belt prior to this (no squeaking, nothing), and that something went wrong during the AC repair (they would have taken the belt off and replaced it to get to the compressor, no?), and I"m having trouble swallowing the $550+ in labor. The car also went through full Mercedes inspection at time of the AC repair, and again no indication of trouble. Any thoughts on this would be welcome....many thanks.
When S**t happens, that is strange coincidence.
But you did not take pictures when the noise started and now all the evidence is gone?
Talk to SA for job discount in those circumstances, but you don't have much of case after driving 30 miles.
Idler pulley cost about $20, belt about the same, so how they made it $550?
Thanks very much for the reply. I didn't take a pic when I picked the car up, the squeaking that I heard was slight, I thought it was just a belt that was settling in or something after the repair, figured if it didn't improve after the day's drive I would take it back in. I did take a picture when the serpentine belt failed (attached here). It just seems far too coincidental......any other thoughts appreciated.
As them point blank if they removed the idler when they replaced the compressor. Can't really tell from the picture but it looks like it's a little off. Maybe it got mis threader or it's just the angle from the picture. I think one of those idlers also has a washer behind it, the other one doesn't. It could still be a coincidence though, they do go bad in that 60k range. I replaced the tensioner both idlers and the belt around 60k as it was starting to make noise. The kit from rockauto was only $120 and an indy did it for me, it was just a few bolts so less than an hour and around $50 for labor, did the thermostat at the same time too as you have to take the idler off to replace it.
Pulley is covered with corrosion so I would bet it is the original pulley with 10 years and 67,000 miles on it. I replace pulleys every 60K and check them at 30K and 45K; checking pulleys is a 10 minute job to remove the belt, spin the pulleys to check for roughness, then reinstall the belt. This failure is coincidence IMO. While replacing the failed pulley, you might as well replace all pulleys and tensioners.
Incidents like this is why I practice preventive maintenance. Costs a bit more up front but the work is performed on my schedule and not on the side of a turnpike in the winter.
With picture taken at angle can't say for sure, but looks to me that top pulley sits on its flange, meaning the bearing dropped the *****.
I would question the dealer inspection. Usually takes some tome for bearing to go from making noise to dropping the *****, so the bearing had to have signs of failure 300 miles before.
It is possible the AC Compressor is not aligned properly with the other pulleys. This may happen if using aftermarket parts. If so, then the belt will not run properly and will exacerbate any worn pulleys you may have. No pulley and/or bearing lasts forever. I would check all of the pulleys and bearings that touch the belt. See if there is any noise or excess movement. You should also make sure there are no rubber bits in between the grooves of every pulley. Any bit of debris will just wear out the new belt faster. Btw, the idler pulley is so very easy to replace. Get a new belt, a new idler pulley and do it yourself!
upper idler pullies do not need to be touched to install that compressor. That compressor is not aftermarket if repairs were done at a MB dealer. The upper idler pulley just failed IMO. Like above said, original. I can also tell your tensioner is worn too. Belt recessed/riding on edge of tensioner pulley. A good/decent tech would of made note of these original components. For the price of that a/c repair I myself would up sell parts only and install them for free just to get the customer to come back. But competence can be super low depending on location. However don't pay to have these repairs done. Do them yourself. Takes 15 minutes with the exception of cleaning the debris from the pullies/grooves.
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