Alternator replacement DIY? '01 3.0L

[DillonInCO]

Well, my X5 left me stranded for the first time the other day. The battery light came on solid red while I was driving around. I got maybe a few miles after that and had to be towed home. I'm wanting to replace the alternator myself to save money---they are ridiculously expensive enough already---but one look at its location has me going, uhhh...where do I start? Searched for some DIY write ups but all I found was for the V8s. Maybe it's the same as the 3.0L E46 or E39 (lots of write ups on those)? Or maybe I wasn't looking in the right spot? Thanks in advance.

[Joshdub]

I have done this twice now, as the first alternator I received turned out to be defective. It is very easy.

Here is a quick and dirty run down.

Step 1) Remove the fan clutch/radiator shroud. The fan clutch takes a long 32mm wrench, they are available on ebay or perhaps a local enthusiast has one you can borrow. They have to come out together as there is no room to wiggle past the other.

Step 3) Undo the serp belt.

step 4) Unbolt the power steering reservoir bolts. There are two right on top of the bracket in between the power steering res and the oil filter housing. The power steering res is now free to be moved out of the way as needed.

Step 5) Remove the airbox and intake tube. You can just disconnect the intake to where it joins the intake boot, no need to take the boot off the throttle body, although now is a good time to replace the boot if yours is old.

step 6) unclip the wiring harness that is located on the top of the back side of the alternator.

Step 7) Unbolt the lead connected to the back side of the alternator. Mine was a 17mm nut.

Step 8) Unbolt the upper and lower two bolts holding the alternator to the bracket. There are no nuts on the backside of these bolts, they thread directly into the bracket.

Step 9) alternator is now free. Wiggle it up through the to where the power steering res and intake used to be. Be mindful of the coolant hoses and coolant reservoir.

Installation is the same as removal. Make sure you get the air duct on the bottom of the alt hooked back up.

Once you get in there it is really quiet self explanatory. Good luck.

[white46]

Yes, the procedure is same as e46 and e39 on m52tu or m54 engines.

Have you thought about replacing voltage regulator? Because failure on voltage regulator is way more common than actual alternator failure.

[DillonInCO]

Thanks! Is there any way to test whether it's the voltage regulator / brushes or the actual alternator itself? It'd be rough if I replaced only the regulator and it turns out that I have to go do the whole job again with a new alternator...I need my X back ASAP and am hoping to have it up and running this weekend.

[upallnight]

While you are in there, replace the oil filter housing gasket if you never replaced it and since you are asking about how to replace the alternator I am quite certain that you never replaced it. It's just 6 more bolts once the alternator is removed.

Hardest part will be to remove the clutch fan if you don't have the special tool. Remember the clutch has left hand thread so it righty loosey lefty tighty as you face the engine from the front.

There an excellent video on Youtube on replacing the Oil Filter Housing Gasket.

[cn90]

I don't have the DIY for X5, but I wrote the OFH Gasket for my 1998 528i, basically very very similar to your X5.

NOTE: "Freeze plugs" in the OFH only apply for 1997 and 1998 models.

1. OFH Gasket:
1998 528I Oil Filter Housing Gasket & “Freeze Plugs” Repair (E39) - Bimmerfest - BMW Forums

The Alternator is mounted to the OFH itself.

2. Many rebuilt alternators from local parts store these days are a piece of junk, i.e. poorly built.

So get a new alternator to prevent being starnded from a poorly rebuilt alternator.
So google search: Bosch AL0703N (better than AL0703X).

"N" = New
"X" = Rebuilt

[cn90]

PS: Fan Clutch.

1. Soak the Fan Clutch Nut way ahead of time: get a drinking straw and pour some PB Blaster down the straw in such a way that the penetrating oil gets to the interface of the nut and the WP shaft (a very tight space).


2. During re-installation of the Fan Clutch nut, it is very difficult to start the threads. Here is my "Poultry Cord" trick:

http://www.bimmerfest.com/forums/sho...d.php?t=240143

[StephenVA]

I used CN90 tips and trick on my own E39 528 oil leak at the oil filter housing/alternator bracket. Easy job just a bunch a bolts and nuts.

The trick I found helpful was the longer wrench sold on ebay as the BMW one is real short and I could not get any leverage. With the aftermarket one is was simple. The job takes approx 5 hrs including setting up and cleaning up.

+1 on the regulator and then the new alternator. Any auto parts store can test your alternator to see if good or bad.

[cn90]

Call eeuroparts and make sure it is a brand-new alternator before buying it:

12317501599 Alternator (120a) (New) - Bosch AL0703N - Free Shipping

[lo_jack]

Clean off the fan clutch threads on the water pump and the nut on the fan and then put anti-seize on them when you reinstall it. Then you can back it off with a good pop with a wrench and something to hold the pulley still next time you have to take it off.

The aluminum water pump pulley upgrade is nearly worth it just because you can wedge a screwdriver in it and get the fan off easily-- with anti seize, potentially without a wench at all. The fan nut isn't on tight because it's left hand threaded, as noted previously.