|
alternator belt failure
I had an alternator belt failure, on-track, at LRP last week in my 2015 M4.
The warning came up on the iDrive screen about a battery recharging malfunction. Tested the battery, car on/off w/a volt meter, and it definitely wasn't charging. Can't see past the intake ducting under the hood, even w/a flashlight, to determine what's going on w/the belts (didn't know it was an alternator belt or other problem). Tried to limp home after fully charging the battery but the battery totally discharged.
A few points:
1) When the Li Ion battery discharges, there is no residual voltage (as in a lead acid battery), so NOTHING functions, including your hazard flashers. I had my windows down and couldn't put them up. Can't access the trunk (no redundant lock cylinder), etc. Luckily a friend jumped me to get power (wouldn't start the car) so I could close the windows and access the trunk. A safety concern, as it was getting dark and I was on the shoulder of a 50mph road
2) The failure of the belt was due to an idler pulley bearing which damaged the alternator belt, I'm sure because of the idler pulley buinding, causing the belt to fail
3) I assume this happened on the track due to consistent high revs but also the fact that my car has 12,000 miles on it now (production date May 2014) and that may be as far as the idler pulley can make it. FYI - this was my third track day of the season. Belt/idler passed track check-out inspection and the shop checked the belts (although quickly, because the car is so new).
This possibly should also be in the mechanical/maintenance/TSB section, also.
Anyone else?
|