southernwake

Friday afternoon I was borrowing a friend's 4runner to help my gf move. we are almost done and I get a call from my friend who has my car, asking if I have recently changed the serpentine belt. They inform me that it broke, then they inform me that a pulley has also broke and is lodged against the motor. So naturally I'm a little concerned about which pulley and the term "lodged" in regards to the motor. Get there and I find the idler pulley that is roughly a year old has torn off the bearing and had wrapped the belt up in it and jammed against the area it mounts.

I have never seen a pulley do this and was wondering if any one else has had this issue I ordered the idler pulley off of partsgeek.com and never had any issue til now. The bearing is still good and turns smooth. It looks like the pulley was spinning around the bearing and just work hardened the metal and it pulled the pulley off the bearing and the pulley chewed through the belt.

Gramma_Benz

Tons of threads about this, just search "Idler pulley" in this forum:

Here's just one of many:
https://mbworld.org/forums/c32-amg-c55-amg-w203/270130-stock-c32-m112k-owners-check-your-oe-idler-pulley.html

southernwake

I appreciate it. That thread is what made me decide to change the idler pulley last year, I was hearing those noises and changed it out. There were no noises this time.

Just curious to see if anyone has had an issue with this pulley from partsgeek.com. I ordered another one and belt from them. I plan on ordering an OEM unit as well. Just wondering if it was a fluke or the unit is just weak.

Thanks,

Wilsophia

I have the same problem with you last month,

Replaced the idler pulley and water pump.....fixed

KJI3jflarryfe93

Did you get an oem quality replacement pulley or something like Tructec crap.
Litens, Ina, Febi are good stuff.

If I remember correct Gates was used on w203 cars, don't know if they are any good?

Did your belt grind on any metalparts of your engine?
Could be costly.

southernwake

Its an OES part, from what I can tell and have seen its the same as what you would get from the dealer. It comes with new bolt and cap ( covers the bearing) and the cap has a MB part number on it.

I bought a new Gates belt.

Belt didnt grind on anything, it looks like the pulley failed and the edge of the pulley sliced though the belt lengthwise and then broke. The belt wasnt wrapped up in the supercharger pulley, the crank or anything like that. It was loosely wrapped some around the pulley that failed and around some accessory pulleys like alt and ac. Once i get the new pulley and belt in I will make sure everything spins true. From what I have looked at so far and tested everything is fine, other than the pulley that failed.