Deflection pulley available at Autozone

[Dannys M3]

If you are as unlucky as I am, parts will break at the most inopportune time. Thursday driving home my first hint that there was a problem. The AC stopped working. As I took the highway off ramp, I was like OH SHIT , power steering was gone also.
As I tore into the car I could see the deflection pulley (#6 in drawing) was fried and bearings were laying at the bottom. As usual none of the local dealerships have the part in stock and I can't wait till Tuesday as this is my only car. After hours of research I managed to find an exact replacement from Autozone.I still had to order it but as least with next day air it would show up Saturday. Duralast 231163 is a 80mm exact replacement.
With 130K miles parts are starting to show their age. Going back together the radiator over flow hose snapped at the plastic connection to the larger hose. I hope my research can benefit someone else looking for this part when the dealerships do not have it in stock.

[WinterSoldier]

130k miles! Bravo!

[Richbot]

Yeah after seeing these fly apart on my other BMW's I plan to proactively replace all the bearings accessory pulleys and tensioners at ~100k

If you haven't already id recommend doing the main drive tensioner and idler as well

[thetastelingers]

Glad to hear you can get those parts at the "RED" stores.

Thanks for sharing.

[Dannys M3]

Originally Posted by Richbot

Yeah after seeing these fly apart on my other BMW's I plan to proactively replace all the bearings accessory pulleys and tensioners at ~100k

If you haven't already id recommend doing the main drive tensioner and idler as well

I can see replacing all the remaining pulleys soon. Have you had a tensioner arm fail and what were the symptoms? With my bad luck it would be cheap insurance. Can someone with access to TIS find the torque specs for me?

[Killerfish2012]

Hi guys, saw this thread a while ago, and was going to replace my deflection (Idler) pulley during my Under driver pulley install, since she was over 100K miles, and I guess I bought part number: 11287841228 instead of 11287841531. Both of these part numbers are listed on real oem for my vehicle based on build date : '09 M3 coupe. Needless to say the idler pulley did not fit. Take a look at the difference between the two pulleys:


My mechanic made a call to both advanced auto parts, and I think Napa, and they both brought the same pulley that did not fit, based on my build date, and car. I then called autozone, which said they would have to place an order for the duralast part number that OP wrote here. This was a good thing, since I was not too crazy about the brand duralast, based on negative prior experiences. I finally called my dealer, who used my VIN number to search, and it came up with part number: 11287841531. I ordered it through thischerbmw, and received it today. It will go in when next I visit my mechanic. I just wanted to do this write up as a heads up for anyone considering this maintenance item. It's IMHO best to use oem, as my oem part is fine at over 100K miles, but please beware: If you're not going to risk the duralast part, then get it from the dealer or thischerbmw online, using your vin number to get the correct part, as these parts are not interchangeable as indicated by real oem, and many standard part number search mechanisms.