[nissubaru]

This is on an N54.

Got the old alternator out just fine, although a bit of a pain in the ass. Had to lift up the intake manifold a little bit to get it out.

Went to install the new one and while I can get it down where it needs to be just fine, I can't get the bolt holes to actually line up. Mainly the 2 bolt holes on the bottom than the 2 on top. I checked the orientation on the alternator and it should be fine but it looks like I'm dealing with basically no clearance and the alternator is on a bit of an angle so it's really tight. I keep hitting the oil filter housing too.

Is there some trick to the install that I'm missing? Kinda feel like an idiot fumbling around when it seems like such a simple task.

Thanks

[BeastMode335i]

Originally Posted by nissubaru

This is on an N54.

Got the old alternator out just fine, although a bit of a pain in the ass. Had to lift up the intake manifold a little bit to get it out.

Went to install the new one and while I can get it down where it needs to be just fine, I can't get the bolt holes to actually line up. Mainly the 2 bolt holes on the bottom than the 2 on top. I checked the orientation on the alternator and it should be fine but it looks like I'm dealing with basically no clearance and the alternator is on a bit of an angle so it's really tight. I keep hitting the oil filter housing too.

Is there some trick to the install that I'm missing? Kinda feel like an idiot fumbling around when it seems like such a simple task.

Thanks

You sure you have the right alternator, and not one from an N52 or N55, or just any other motor besides N54..??

[Navy Doc]

Originally Posted by nissubaru

This is on an N54.

Got the old alternator out just fine, although a bit of a pain in the ass. Had to lift up the intake manifold a little bit to get it out.

Went to install the new one and while I can get it down where it needs to be just fine, I can't get the bolt holes to actually line up. Mainly the 2 bolt holes on the bottom than the 2 on top. I checked the orientation on the alternator and it should be fine but it looks like I'm dealing with basically no clearance and the alternator is on a bit of an angle so it's really tight. I keep hitting the oil filter housing too.

Is there some trick to the install that I'm missing? Kinda feel like an idiot fumbling around when it seems like such a simple task.

Thanks

I literally went through this 3 days ago. If the alternator has slid into place past the intake manifold then the hard part is done. I used a large flathead screwdriver to nudge the alternator so the align the holes.
As stated above....... Make sure you have the correct alternator. If you do then the holes will line up. May take some encouragement.

Good luck.

[nissubaru]

Originally Posted by BeastMode335i

You sure you have the right alternator, and not one from an N52 or N55, or just any other motor besides N54..??

ACDELCO 3342828 which is listed as 180amp remanufactured Bosch. I'll go check the box though for certainty since it's out in my other car.

[rick100]

Why not just compare it to the one u removed

[nissubaru]

Originally Posted by Navy Doc

I literally went through this 3 days ago. If the alternator has slid into place past the intake manifold then the hard part is done. I used a large flathead screwdriver to nudge the alternator so the align the holes.
As stated above....... Make sure you have the correct alternator. If you do then the holes will line up. May take some encouragement.

Good luck.

Saw your post actually, glad you chimed in. I tried to use a flathead but I wasn't having much luck. I was sorta in a rush though so I'll try again today after work.

Do you remember if you slid the alternator in from the intake manifold side or the side closer to the radiator fan? Or align the holes first and then push it straight down into the alternator mounting point?

[nissubaru]

Originally Posted by rick100

Why not just compare it to the one u removed

I did that lol but what I don't know is if another BMW motor has an extremely similar looking alternator with slightly different mounting points. For instance, the ones on the N52 look very similar but the mounting points could be millimeters apart for all I know. Putting them side by side is pretty accurate but I'm basically struggling with 1mm of clearance.

Almost wanna dremel some of the material away to make it less of a tight fit lol but that's a last resort.

[Navy Doc]

Originally Posted by nissubaru

Saw your post actually, glad you chimed in. I tried to use a flathead but I wasn't having much luck. I was sorta in a rush though so I'll try again today after work.

Do you remember if you slid the alternator in from the intake manifold side or the side closer to the radiator fan? Or align the holes first and then push it straight down into the alternator mounting point?

I removed the intake manifold completely. The alternator was slid in from the manifold side. Not sure if it's possible, but is there a chance that you put it in upside down? What I mean is the ground wire and positive plug should be facing outboard away from the engine block. If they are facing inboard towards the engine block then I can imagine that the holes would not line up. If you can take some pics so that I can see the orientation that you have it placed.

[nissubaru]

Video of me fumbling around with the alternator. Still couldn't get the damn thing to sit in the mounting point. Hopefully you can see what I'm struggling with in the video.

I don't have the intake manifold fully removed but I have it pulled up enough that I can slide the alternator in from the intake manifold side without having clearance issues. Problem with coming from this side is I just barely clip the mounting point on the left in the video (~25 second mark).

Then around the 1:05 mark you see how it keeps falling to the fan side of the engine and I can't get the alternator around the lip of the mounting points on the right. I have tried to get a screwdriver in there for some leverage but failed each time.

1:35 you see how I'm hitting the oil filter housing from the top.

That's pretty much it. Is everyone else's fitment that tight?? Am I just an idiot? Any suggestions on where to position the alternator and where to put the screwdriver/pry bar to get the alternator to slide into place?

Thanks

[Shane335]

I took my OFH completely off as well as the intake manifold. I used a rubber mallet to nudge the holes to line up.

[chev_chelios]

I did the same job like 6 month ago.
Easy to remove but a PITA to put back togheter. I had to losen the a/c compressor to make some room.

[nissubaru]

Originally Posted by chev_chelios

I did the same job like 6 month ago.
Easy to remove but a PITA to put back togheter. I had to losen the a/c compressor to make some room.

Do you remember if you had to remove the oil filter housing too or just loosen the ac compressor? I really would prefer not to remove the oil filter housing if I can avoid it.

Does anyone know if I have to replace the gasket if I pull the ofh? Its already been replaced so I'd rather not have to replace it again if possible. But if need be I can get it done now that I'm back from my work trip.

[caliber]

did this about 2 years ago. I remember I loosened(not removed) the air-con compressor. Did not touch the OFH but can't remember if I loosened the air intake manifold.

The alternator and compressor are bolted together with 1 or 2 bolts.

[JuniorB]

All n engines use the same alternator, starter and air conditioner if I'm not mistaking. It does say to remove the ofh, but it is possible to maneuver it out

[chev_chelios]

Originally Posted by nissubaru

Do you remember if you had to remove the oil filter housing too or just loosen the ac compressor? I really would prefer not to remove the oil filter housing if I can avoid it.

Does anyone know if I have to replace the gasket if I pull the ofh? Its already been replaced so I'd rather not have to replace it again if possible. But if need be I can get it done now that I'm back from my work trip.

No need to remove the oil filter housing but you will need to jack the car to loosen the a/c compressor.

[nissubaru]

Thanks for the replies guys, I'll probably try to loosen the AC compressor first before going down the oil filter housing route.

[nissubaru]

Originally Posted by BimmerGeeks

I always unbolt the OFH to move it slightly. It's literally 3 bolts, if your manifold is already loosened, it takes 5 seconds.

Because I'm a noob with my E90, and I'm always overthinking things... Do I need to drain the oil if I'm just moving the housing? My instincts tell me yes but I'd rather not have to if possible lol

Most of my tools are at my parents cause I've been working on my 300zx so I'm trying to make due with just my tool box

[tlow98]

No, but loosen the oil filter cap so the oil drains to the pan. Will help avoid a much larger mess.

[Navy Doc]

Originally Posted by nissubaru

Video of me fumbling around with the alternator. Still couldn't get the damn thing to sit in the mounting point. Hopefully you can see what I'm struggling with in the video.

I don't have the intake manifold fully removed but I have it pulled up enough that I can slide the alternator in from the intake manifold side without having clearance issues. Problem with coming from this side is I just barely clip the mounting point on the left in the video (~25 second mark).

Then around the 1:05 mark you see how it keeps falling to the fan side of the engine and I can't get the alternator around the lip of the mounting points on the right. I have tried to get a screwdriver in there for some leverage but failed each time.

1:35 you see how I'm hitting the oil filter housing from the top.

That's pretty much it. Is everyone else's fitment that tight?? Am I just an idiot? Any suggestions on where to position the alternator and where to put the screwdriver/pry bar to get the alternator to slide into place?

Thanks

Have you figured this out yet? Looking at your video I can't see the negative terminal post. From your position it should be pointing towards you. If it is on the other side of the alternator then you don't have in the correct orientation.

[PhaseP]

Originally Posted by nissubaru

Video of me fumbling around with the alternator. Still couldn't get the damn thing to sit in the mounting point. Hopefully you can see what I'm struggling with in the video.

I don't have the intake manifold fully removed but I have it pulled up enough that I can slide the alternator in from the intake manifold side without having clearance issues. Problem with coming from this side is I just barely clip the mounting point on the left in the video (~25 second mark).

Then around the 1:05 mark you see how it keeps falling to the fan side of the engine and I can't get the alternator around the lip of the mounting points on the right. I have tried to get a screwdriver in there for some leverage but failed each time.

1:35 you see how I'm hitting the oil filter housing from the top.

That's pretty much it. Is everyone else's fitment that tight?? Am I just an idiot? Any suggestions on where to position the alternator and where to put the screwdriver/pry bar to get the alternator to slide into place?

Thanks

I don't have N54, so commenting just looking at your video, and the fact that it got out without problem, it must be a matter of using same orientation as it got out.

I think if you initially tilt down at start(the pulley pointing down a bit), at the same time aligning the start at the bottom, then as you slide it in, gradually tilt back up to horizontal it may go in. Initial tilt down may be needed to clear the OFH.

[PhaseP]

Shop manual says loosen (set aside) the AC compressor, and loosen the bracket:

http://workshop-manuals.com/bmw/3_se...ernator_(n54)/

[NoSole]

I know this thread is old, but this info is pertinent, so I'll share for the benefit of future DIYers.

I had been wrestling with this issue, so rather than getting sucked into doing just the minimum, I learned from my past failed shortcuts and decided to do it right. You do not need to remove the OFH, and I'm quite sure I also could've done it without messing with the intake manifold (however, moving the supply tubes did grant a great deal of working room that made my process a whole lot easier).

The answer to your problems...

1. Detach the AC compressor (do not detach the refrigerant lines).
2. The bottom bolt is a mother to get to. So remove the wheel well to give you access from underneath as you'll be unable to access it from the top.
3. Move it a few inches so you can access the mounting bracket.
4. Loosen (do not remove) the three bolts to give you more wiggle room.

Because pics are the best....
Remove AC compressor
Remove alternator
These links also include torque specs for the bolts

The two lower bolts on the alternator feed in through this mounting bracket, which, if tight, will also act as a clamp on the lower flange. Before I jumped through the hoops to clear these steps, the clamping pressure on the completely disconnected alternator was so great, that I was concerned there was still one hidden bolt keeping it attached. Knowing what I know now, I probably could've gotten it out if I really tried, but certainly not without damaging something, and there's no way in hell I would've gotten the new one in. Loosening the mounting bracket underneath made the alternator a piece of cake to pull out and put in. I didn't even need to move the intake manifold.

And lastly, be patient! There are some tedious moments and you don't wanna make it longer by losing a bolt, breaking a clip, or puncturing a vacuum line!