[weq92f]

.
This is an informational post intended for those swapping an alternator on a 2007 e90 335.

I've just successfully finished this repair at my home shop and thought I'd do a small write up here for any future DIYers that may benefit.

Parts: BMW OEM Alt purchased from FCP Euro: total: 470 incl 50 core charge. ( 180 amp w/regulator ).

All 4 alt bolts were NOT aluminum so they were reused.
Couple feet of vacuum hose

Steps I took on my '07 model turbo 3 series:

1) Disconnect the Battery in the trunk

2) Remove the cabin filter housing, engine cover

3) Remove the air intake ducting and air filter housing

I did not remove the electric fan here but it can be removed to create additional room for the next few steps

4) loosen but do not remove the two torx screws that attach the charge pipe to the front of the block. This will allow the charge pipe to be moved down and away enough so that the T60 torx socket can be used to remove tension ( via the belt tensioner ) from the belt so that the belt can be removed from the alternator

5) using a T60 torx socket and a breaker bar, relieve the tension from the belt and remove the belt from the alternator. Support the belt with a strap to keep it from falling and coming off the other pulleys.

6) Remove the boost pipe. ( This requires disconnecting two boost redirect hoses, a sensor in the boost pipe, both ends of the boost pipe )

7) Remove all intake fasteners. Gently lift the intake just to the top of the studs that hold it down and slightly to the rear of the car...Just enough to get it up and slightly to the rear ( and out of the way of the alternator. What we want is that alternator to rotate top backward toward rear of car.

8) remove the 4 bolts that mount the alternator.

9) use a rubber mallet to move the alternator. It will move only for and aft and up and down due to the bottom bracket having a strong hold on it. The thing needs to rotate back toward rear of car a long way then it will need to be further persuaded out of the bottom bracket with more force. I used a combination of a pry bar and the mallet to get it to pop out of there.

You do not need to remove or loosen the Oil filter housing or the A/C compressor on the '07 model.]

Now install is the reverse yada, yada. But...

Here's the trick I used to make it easier... I took my file and took the edges off the lower mounting bosses of the new alternator. Also used the file on the lower bracket in the car to remove some of the edges there. Essentially what I did was make somewhat of a wedge shape on the lower mounting boss on the new alternator. Then made a receiving flange on the lower bracket on the car.

It still took some wrangling to get the new alternator in. Once in, these mods did not cause any issues with alignment or seating as plenty of material was left to manage that.

Once buttoned up, battery charged to full, engine running I observed 14v at the battery.

Hth,

-klb

Nice

They'd def appreciate this in the DIY section too:
https://www.e90post.com/forums/forumdisplay.php?f=172

[weq92f]

Right...That's where it should have gone to begin with...LOL. I was just eager to get it off my brain so it landed here!

-klb

[Jklad]

Originally Posted by weq92f

.
This is an informational post intended for those swapping an alternator on a 2007 e90 335.

I've just successfully finished this repair at my home shop and thought I'd do a small write up here for any future DIYers that may benefit.

Parts: BMW OEM Alt purchased from FCP Euro: total: 470 incl 50 core charge. ( 180 amp w/regulator ).

All 4 alt bolts were NOT aluminum so they were reused.
Couple feet of vacuum hose

Steps I took on my '07 model turbo 3 series:

1) Disconnect the Battery in the trunk

2) Remove the cabin filter housing, engine cover

3) Remove the air intake ducting and air filter housing

I did not remove the electric fan here but it can be removed to create additional room for the next few steps

4) loosen but do not remove the two torx screws that attach the charge pipe to the front of the block. This will allow the charge pipe to be moved down and away enough so that the T60 torx socket can be used to remove tension ( via the belt tensioner ) from the belt so that the belt can be removed from the alternator

5) using a T60 torx socket and a breaker bar, relieve the tension from the belt and remove the belt from the alternator. Support the belt with a strap to keep it from falling and coming off the other pulleys.

6) Remove the boost pipe. ( This requires disconnecting two boost redirect hoses, a sensor in the boost pipe, both ends of the boost pipe )

7) Remove all intake fasteners. Gently lift the intake just to the top of the studs that hold it down and slightly to the rear of the car...Just enough to get it up and slightly to the rear ( and out of the way of the alternator. What we want is that alternator to rotate top backward toward rear of car.

8) remove the 4 bolts that mount the alternator.

9) use a rubber mallet to move the alternator. It will move only for and aft and up and down due to the bottom bracket having a strong hold on it. The thing needs to rotate back toward rear of car a long way then it will need to be further persuaded out of the bottom bracket with more force. I used a combination of a pry bar and the mallet to get it to pop out of there.

You do not need to remove or loosen the Oil filter housing or the A/C compressor on the '07 model.]

Now install is the reverse yada, yada. But...

Here's the trick I used to make it easier... I took my file and took the edges off the lower mounting bosses of the new alternator. Also used the file on the lower bracket in the car to remove some of the edges there. Essentially what I did was make somewhat of a wedge shape on the lower mounting boss on the new alternator. Then made a receiving flange on the lower bracket on the car.

It still took some wrangling to get the new alternator in. Once in, these mods did not cause any issues with alignment or seating as plenty of material was left to manage that.

Once buttoned up, battery charged to full, engine running I observed 14v at the battery.

Hth,

-klb

Pics or it didn't happen

Great write up - the alternator is one of the few peripheral engine components that I have not yet replaced on my car, I'm just waiting for it to fail one day and leave me stranded.

[weq92f]

.
It will happen! FWIW mine failed at 130k miles. I've been tuned since 50k miles and I drive it hard.

Hth,

-klb