turbo_mustang12

Anybody have instructions on replacing a alternator on a 2005 545i? Or does anybody know what needs to be removed to get to it or whats the easiest way to get to it? Thanks in advance

turbo_mustang12

Also how do u know if its the actual alternator or the voltage regulator?

carfucious

I don't know if this has already been answered elsewhere, but...

Mine acted up the other day, flasning lights, error codes, little picture of battery in "red" and the car slowly died as I was sweating bullets trying to get off the freeway.
I ordered a reman locally, then returned it. Instead AI found a suitable replacement, made by Valeo, the oem supplier. The unit came missing the small idler pulley that you will need. I checked with the dealer ($80-what an insult)and got it locally for about $40. I didn't want to try and re-use my old one as that has 85k miles that the car has on it-not worth the risk of another failure.
The removal process is fairly involved, if you have done an alternator bfore keep in mind that removal of the oil cooler from the back of the radiator is required, but you do not have to remove it entirely form the vehicle as described in many publications, it will move out of the way enough. You will need to remove the radiator covers, the lower belly cover, the small coolant overflow line (mine broke-$70 from the thieving dealer)and the upper radiator hose, also the fans and all the associated wiring. Once that is out of the way it is a little hard to get out of there, but certainly doable.

Just so you know what you are in for.

1naprice

Was it the alternator....or the voltage regulator? My car just cut off while on the freeway last night..the display started blinking ..and the power went off as well as the engine! I had the alternator tested today ..and it came back fine...I just got a new battery 2 months ago...

carfucious

I am not sure if the question is for the OP or me.

I'll answer for my situation. I was reluctant to keep driving it after it acted up, that is why I went ahead and replaced the alternator. I am not sure if the voltage regulator is in question, but in my case my vehicle has 80,000 miles on it so I thought it good insurance to just replace it. If you have significantly less mileage you may be confortable with it and feel it may be worth taking the risk.
I took apart the old alternator and the brushes (metal armature contacts) were very worn.

buddy

Just curious did you have the battery recoded to the car? I ask because there has been a discusion on the board about what may happen if it is not recoded the car has issues with knowing the true voltage and may give error codes and possible drivability issues.

From what I have read anyway

carfucious

If you mean when I replaced the alternator, no, I just reconnected the battery after I was done.

If there is anything to this battery recoding I have not discovered it at any time. I replaced my battery about 2-3 years ago. I have suspicions about some of the things I hear coming out of dealerships. But knowing that many of the parts and services are double or triple any other source leads me to believe a lot of these "dealer-only" services are only trying to protect their market. I wonder how much business they would have if they just set reasonable margins and just did a good job.

NeverEnough!

I just did it yesterday. I used the Bentley manual, which anyone who works on their E60 should have. I did not need to remove the trans cooler, but I did remove the idler pulley from the alternator before I pulled the alternator forward to give me more room. You also need to remove the engine cover, airbox, duct, vac connect and MAF plug, radiator covers and the electric fan. You will need to pin the main idler tensioner assembly back (I used a large cotter pin) to give enough room. I also put cardboard over the radiator surface so I didn't damage the fins. DON'T FORGET TO DISCONNECT THE BATTERY IN THE TRUNK!!! The manual tells you to remove the wiring before pulling the alt out, but there is just no way to do that. The two front bolts going through the alt are the only fasteners that need to come out to release the alt. Pull the alternator only far enough forward to allow you to release the two cables from the clip just over the front of the alt. That cable and wire go to the back of the alt. One is the battery+ and the second, smaller diameter wire goes into a connector next to the batt+ connection. I used a couple of small cardboard boxes in area between the radiator and pulleys to rest the alt on so I could remove the wires without putting a strain on my back or the wires. Be careful, you don't have much extra wire length! The batt cable will fight you a little as you are removing the alt. Don't kink the small wire and watch for the cooler and the plastic manifold above it on the driver's side of the radiator. They both look really fragile. Unusual tools you will need include a torque wrench, Torx T60 and Torx T20. It was difficult to get the alt around the lower mount (the alt foot is U shaped) and even harder to get it lined up to go back in. I used a tapered nail set punch (no hammer!) in the lower mount to center the hole first, followed by a pretty good fitting drift punch to more closely align the lower hole. Once I had that, I inserted the top bolt, which then allowed me to swap the long bolt for the drift punch in the lower hole. The alt is heavy and you will need some leverage - I used a flat, thin pry bar beneath the alt to position it for the top bolt. BE GENTLE! After I buttoned everything up I reconnected the battery and started the car. You will need to re-set both the windows and the active steering (if you have a Sport). The IBS needed the normal 3 hours to re-set itself. Today the car took an hour to go to sleep instead of the normal 16 minutes. Hopefully this will straighten out without needing to re-code the battery because of the disconnect or all the goofy voltage drops before the new alt. I was using a CTEK charger, so we'll see. The good news is that although the alt output voltage pre-procedure was 10.5V and falling, the post procedure output was 13.5V. The car did fast idle after its first test drive last night, but I think that was just the IBS having not re-set itself. When I fired it up this A.M., the idle dropped down to about 500 rpm as soon as the car was warmed up. I've done a lot of mechanical work on cars in my time, but this was pretty grueling. WARNING: The alt is not easy to get to, there is no room around it and you cannot see beside or behind it. Had I known what I was in for, I might have paid my mechanic the $300 he wanted for the job.

NeverEnough!

Follow Up Post: The alternator replacement cured all of my error messages and the car has run flawlessly since the install. The IBS reset itself after a couple of cycles and the car now goes to sleep normally. NOTE: I believe that since the IBS' job is to monitor the battery a reprogram is not needed when replacing the alternator. It should be recoded if you replace the battery at the same time as the alternator though. Of additional note: My 2004 545i needed a new IBS some time prior to installing the alternator - It did not need to be recoded as it had no history stored yet.

salaki

Thanks for the write up..

I'm saving this thread when I need alternator in the future

So if you replace the whole alternator, does it mean you replaced both alternator and voltage regulator as well?

I'm seeing online for Valeo 180A for $296 brand new but around $220 for remanufactured in local Autozone/Napa w/ lifetime warranty.

I wonder if the reman will actually last longer than Valeo OEM.
I mean the OEM is Valeo and it doesn't last long.