Alternator & Crank Pulley

[ahshawn]

Hi fellow forummers,

Sharing my experience recently for my E90 320d LCI 2009:

1. Was driving when my transmission fault light fired up and went to limp mode (yellow gears). Brought it to workshop in Ipoh and found out it was a incorrect gear ratio fault code for gear 1,2. Foreman concluded it could be a one-off issue since i was driving down a steep ramp when it happened. He explained that it could be due to the gear kicking down to 1st but incorrectly read as 2nd ..idk how true is this since i assume tranny systems are pretty reliable

2. All fine and dandy til 1 week later, fault codes starting firing up randomly. First ABS, then Parking Brake, then Flat Tire, then Transmission, then Airbag. Lights on the radio were flickering. I suspect alternator already, I quickly shutoff the AC and crawled to my workshop nearby in limp mode. Fault codes revealed that "compression of clutch" related to tranny caused the tranny light to fire up. A host of other fault codes also came up, all related to insufficient power supply issue.

3. Confirmed alternator failure, but did not diagnose if it was a regulator fault or a bearing seizure fault. Says that in the event of either failing, the alternator units are sold in whole components (including pulley, regulator and alternator)

Part no: 12317802619
Cost including labour: RM 1,950

4. Subsequent check revealed no further fault codes re-appearing, giving an interim conclusion that the tranny fault light is related to insufficient power to the system and the alternator had been intermittently failing.

5. Another check at the pulleys revealed Belt Drive Vibration Damper had some cracking on the rubber. Was advised to change this as preventive maintenance since failure could result in catastrophic collateral damage especially at high speed. My mileage is only at 130k. I will try to get some pictures posted up for reference to the condition of the pulley.

Part no.: 11237823191
Cost incl. labour: RM 1,500


I do however have questions arising from my recent experience at workshop:

1. Is it true that the alternator, regulator and pulley comes in an integrated unit. Even if i managed to isolate the fault to the regulator, I have no choice but to replace the entire unit

2. Can the alternator be rebuilt to be sold off as parts? If so, can any forumer advise on this

3. Is it common for the pulley to deteriorate at 130k mileage? Or is this a wear item that has large variation in lifespans?

4.. Are the prices of the alternator and pulley considered to be reasonable? I have seen very large variation prices on these items as such I could not ascertain if they were fair price (these are all new units)

Thanks!

 

[ahshawn]

Updated photos of the pulley showing signs of cracks

 

[jarance]

When you car start to light up with so many "alarm", it mean the battery voltage is very low and caused the modules to "fail".
The possibilities of so many alarm appearing at the same time is 1 in a million.

The alternator failure could be due to worn out carbon brush for the slip ring. Not many shop are willing to do this replacement work cos the carbon brush are about RM15 per pair. However, it is labour intensive as it involved removing the alternator to service it.

As for the pulley showing sign of crack, do a dye penetrant test to confirm the hairline crack.

BTW, your fan belt look worn out. Get it replaced.

I have also a failed alternator while driving. All the alarms came on when the battery is draining. Found the alternator problem is due to worn out carbon brush.
DIY to replace the alternator with new one. Old one is waiting for carbon brush. All work DIY.

 

[jarance]

BTw, I am not sure about the vibration dampener in a BMW. It could be the belt tensioner puller.

I would just buy the pulley without the tensioner. The pulley are the same for stationary pulley and tensioner pulley.
but the stationary pulley are cheaper.

 

[ahshawn]

When you car start to light up with so many "alarm", it mean the battery voltage is very low and caused the modules to "fail".
The possibilities of so many alarm appearing at the same time is 1 in a million.

The alternator failure could be due to worn out carbon brush for the slip ring. Not many shop are willing to do this replacement work cos the carbon brush are about RM15 per pair. However, it is labour intensive as it involved removing the alternator to service it.

As for the pulley showing sign of crack, do a dye penetrant test to confirm the hairline crack.

BTW, your fan belt look worn out. Get it replaced.

I have also a failed alternator while driving. All the alarms came on when the battery is draining. Found the alternator problem is due to worn out carbon brush.
DIY to replace the alternator with new one. Old one is waiting for carbon brush. All work DIY.

Thanks jarance for the response,

Yes, you are right, opening up the alternator revealed to me that one of the two brushes was a bit short. I found a tutorial on youtube for the replacement of these brushes and they look fairly straightforward to replace. The model is a Valeo alternator. I will probably try to get this refurbished and see if it continues to operate. The bearings were free-spinning indicating no seizure

https://www.youtube.com/watch?v=aVvPzwtxdrM

As for the pulley, the hairline cracks were not the only one's present, if you look at the side it is starting to delaminate as well. I could pry open some of these cracks with my finger nails. Had it replaced, just the pulley only. The immediate thing that I noticed after the change is that the jerkiness of gear shifts between 2nd and 3rd gear is far less. Also prior to the change, i noticed that the tranny was hesitant went upshifting and downshifting and low speeds..I am sure this is not related, but the coincidence is unusual. Also slightly less cabin vibration

And yes, thanks for the heads up on the belt, I noticed it too after I saw your post.

 

[jarance]

Wow, the picture of the pulley is frightening. Good that you have it replaced. It look like it going to fail any time.

As for the carbon brush, valeo alternator used 4.5x6.5x15mm carbon brush.

I got mine from Aliexpress for 10 pcs for USD10.45. (about USD2.09/pair)

 

[jarance]

My carbon brush and regulator.