Alternator Replace 2003 530

Originally Posted by cn90

I don't know why people keep saying ATF kills alternator! There is simply no proof for that.

I don't disagree we have no proof.

So I don't know.

Up until you said that, I just "assumed" that the failure mode was thus:

0. Bearing is lubricated with thick grease which is designed to stay inside the race and stick to the balls
1. Power steering fluid slowly seeps out of the hose connection and collects on a bend, where it eventually, and slowly drips on the bearing, like a Guantanamo-Bay water torture ... very slowly solubilizing and dissolving a bit of the thick grease (each seeping drip being perhaps an hour or five apart)
2. This solubilizing and slowly washing away of the packed-in grease happens slow drip by slow drip (maybe three or five drips in a day?) so it takes a year or two to completely wash away the grease
3. Over time, the grease is gone (so the theory goes) and all that is left is a bearing lubricated by one to three drips of power steering fluid in a day.

But, this is OT, so, I'll start a thread asking how we could PROVE this (or not) in the next alternator replacement.
-> E39 (1997 - 2003) > How can we prove a PSF leak is or is not causing E39 alternator bearings to run dry?

Okay, here is the plan. Ordered the regulator since it is cheap (relatively) and will try that as soon as it comes in. Have the full rebuilt alternator waiting at the local parts store just in case.

Pulled the airbox (what a bear to get off the throttle body end!) and the PS reservoir. Lots of seepage from the reservoir and the alternator has a lot of goop on it from the leakage.

Tested the + on the alt and it was good. Pulled the plug and tested that with key on, and it was good.

I can now see how I could POSSIBLY get the alt off if I had to, but think you're right that it would be better the longer way.

Did look at the cooling system. Everything looks shiny and new, so think I am good there.

HERE is something strange (I think). When I pulled the airbox out, I found a spare electrical part laying in that area, hooked up to a loom. Not sure what it is or where it belongs. Can anyone tell me what this is and where it is supposed to reside?




Hate to have odd items rolling around the engine bay!

I can now see that the hose change for the 2 PS reservoir hoses should be okay, assuming I can figure out the attachments at the cooling coil and the pump ends. Not sure how those attach.

But, so far, so good thanks to the help here!

CAUTION: You need to handle all the airbox components and tubes carefully. 10 year old rubber gets brittle and can crack when stressed. The result is an airleak and a lean air condition and code.

Read the BMW part # on that thing.

Go to RealOEM.com and do the part # search.

Offhand that looks like a sensor plug-box that fits onto the driver's side of the radiator. I forget what it is ....

Originally Posted by neilw

I can now see how I could POSSIBLY get the alt off if I had to

You did read post #66 and post #107 and especially post #146 of the aforementioned reference, right?

I must have asked (and the guys answered) every alternator-removal question there is!

Even the key steps missed in that writeup were added back later, as an 'idealized' DIY!

Originally Posted by Fudman

10 year old rubber gets brittle and can crack when stressed.

I was thinking exactly the same thing!

To the OP - this is my lower boot. Notice the little tiny series of cracks in the (hidden underside) 'thumb' of that boot?
Those tiny cracks caused me lean-misfire grief for a year before I found them with a smoke test!

Originally Posted by neilw

Did look at the cooling system. Everything looks shiny and new, so think I am good there.

Doublecheck the date codes to be sure:
- Cooling system date stickers & radiator date codes & markings (1) (2)

Originally Posted by neilw

HERE is something strange (I think). When I pulled the airbox out, I found a spare electrical part laying in that area

Take a look at the thread already mentioned which has a picture of almost everything you'll run into for this repair:
- One users' example of total electrical failure (AAA towed away) alternator repair (1) (2)

Maybe that's the stink sensor?
- Understanding the AUC automatic air recirculation (aka stink) sensor (1)

Originally Posted by neilw

I can now see that the hose change for the 2 PS reservoir hoses should be okay

This may help:
- DIYs to replace the power steering hoses (1) (2) (3) (4) (5).

+1,000,000 for the AUC smell sensor.

Problems resolved (I hope). Thanks for all the help.

Only needed to replace the regulator, not the entire alternator. Works fine now. Tip for others. Need a short/stubby Phillips to get bottom screw out of back. No need to remove the alt.

Replaced power steering reservoir and attached hoses (2). No real problems other than messy.

Got the air box back on. Looks like it may be fairly new since no real distressed areas or cracks. Looks very clean other than intake.

Smell sensor went back where it was supposed to go.

Found label on bottom of radiator when removing underpan. Behr dated 9-12, so my feeling that the entire cooling system has been replaced looks valid. All hoses, couplers, parts look squeaky clean and new, so think I am good for awhile.

Cannot see any date on the battery. Not sure how old. Holds a charge okay, but eye is not green, didnt top out when I had a trickle charger/tender on it during repairs. Thinking I will get a new one just to be sure.

Felt good to be driving it again. Again, thanks to all who helped on this.

I don't know your mileage, but consider rebuilding it soon.

You just need to replace both bearings.
Since you already have a brand new VR.
This should be good for another 150K miles.

Well, thought this problem was solved. Had replaced the regulator and a new battery. Not so lucky. Everything worked fine since I finished about a month ago. Needed to go to major metro 450 miles away to have a good indy shop do my torque converter change-out. They did that, but also found that my water pump had a minor leak as did the brand new Behr radiator, so they changed those plus the tensioner pulleys.

All was fine. Had a great trip. Car ran great. Yesterday did a 200 mile commute to work with no problems. This morning after a short 10 mile drive, went to start the car and got the Battery Light again. 11.4-11.6 volts while running, but 12.4-6 when not running. Decided to drive home to my now well used garage 10 miles away. Voltage stayed at about 11.4 for most all the trip until the very end when it started to bounce up to 12.5 and occasionally 13.5. Did not correspond to high RPMs, so did not seem to correlate to a belt slippage.

Wondering now if I got a bad regulator? I will, of course, check the belt tension because of the new pulleys, and check the connector on the back of the alternator. Can't imagine that anything else in the alternator can cause it to not charge other than the regulator. Also don't think it can be a loose connection somewhere since it has not acted up in a 1,000+ miles of driving until today when it failed outright. A bit strange about how it did start to work somewhat at the tail end of the drive back home, though.

Have a new regulator coming fedex overnight, but open to ideas on anything else this might be.

Okay, replaced the regulator for the second time within 1k miles with another new Bosch unit. Does anyone know if these can fail that quickly (factory defect, etc.), or do I need to be looking for some other problem that may have caused the regulator to fail so soon? Now puts out steady 13.5v at night with everything going except the a/c. New battery still tests good.

I replaced my alternator 2 days ago for the first time (so I had no previous knowledge or experience in doimg so)... it took 2 hours. I did NOT remove the fan shroud. I would just carefully position the ratchet and use a long cheater pipe so I didn't need to have my hands in there. It was a piece O cake ! I think the hardest part was removing the pully off the old alternator. Good luck!

Originally Posted by neilw

Okay, replaced the regulator for the second time within 1k miles with another new Bosch unit. Does anyone know if these can fail that quickly (factory defect, etc.), or do I need to be looking for some other problem that may have caused the regulator to fail so soon? Now puts out steady 13.5v at night with everything going except the a/c. New battery still tests good.

Maybe the slip ring was worn unevenly, have you checked it? It might have needed to be changed, or at least sanded lightly so the brushes have a good surface of contact.

P.S.: the copper part to the left - it has the 2 slip rings for the the 2 brushes. Similar on your alt:

Originally Posted by doru

Maybe the slip ring was worn unevenly, have you checked it? It might have needed to be changed, or at least sanded lightly so the brushes have a good surface of contact.

Hadn't thought of that. Assume I would have to remove the alternator to get at that from what it looked like when I changed the VR.

Does anyone know if you can test the VR once it has been removed to see if it is any good? That might tell me if the VR was bad or if the slip ring is just dirty and now works because it has reseated with a new one.