[nilknarf]

My 2007 e91 is currently at 74,000 miles and has been sluggishly starting for the past 10,000 miles or so. Sometimes worse than others, but usually took a second longer than typcial to start. I was guessing either the starter was going out or I had a weak battery, but the battery light on my 4 year old battery was still green.

The other day, car wouldn't turn over at all and could not be jumped. Battery window was black and remained black after charging overnight, so I thought, ok, battery is 4+ years old and due for replacement anyway so I put in a new one, but still no start.

I then pulled the following error code:
CAS - A0B4 CAS: engine start, starter operation fault currently present
Terminal 50 B6100_6CAS2_50

At this point, I was pretty sure it was the starter. It appeared almost impossible to get to it so that I could test it, so I just hoped for the best and tore everything apart and replaced it with a rebuilt Bosch starter (~$105 Part #: W0133-1888632). Job was hellish in that it took ~7 or 8 hours. Using Bentley, I had to remove microfilter housings, airbox, camshaft cover, and intake manifold. The intake manifold was the worst part because the photos in Bentley were not very good. Now that I know how everything dissassembles, it would probably take me 3 hours if I had to do it again. The only parts that you need besides the starter ane new aluminum mounting bolts (~$8 for package of 2) and new intake manifold gaskets (~$28). I picked those up from the local dealership, but ordered the starter online.

I'm happy to report that the new starter was the cure.

I'm sorry that I couldn't post a detailed DIY, but it took every free second I have right now just to get this job finished. Thought I would throw up a quick summary post in case it helps anyone. We could definitely use a DIY tutorial for this job as I'm guessing a lot of e90 starters will be failing over the next few years.

Frank

[queensfield]

Congratulations and great job on replacing the starter. From what I understand, there is so much stuff one has to remove to get to it. Would be great to see a DIY whenever you can get to it.

[mh666]

I'm having the exact same problem......

The engine wouldn't start, but I have all the cabin lights and all the electronics.
There is no cranking at all, just faint humming noise (not sure whether it's from the engine or from my lux angel eyes)
I tried jumping the battery - didn't work
I removed the battery and brought to the dealer for testing - the battery turned out to be almost brand new.

The guys at the stealership said it's probably the alternator and quoted me $1300 for parts and labour but I thought there are signs before alternator failure, such as loss of power or fainting of lights etc.

The fact that I had slow/delayed cold starts in the morning leads me to think that it's a starter problem....

I would really appreciate a DIY here because I can't land $1300 on my e90 right now...
Subscribed in case a hero posts a detailed DIY for his fellow e90ers.

[nilknarf]

mh666, the alternator shouldn't cause your car not to be able to jump. Also, if your battery was charged, it sounds like the alternator was working. Not sure about the loss of power, but fainting of lights could have been a loose battery connection.

Sure sounds like a starter to me. If you can get your hands on a code reader, it would be helpful to confirm if you get the same error code that I did.

As far as a DIY at this point, I would invest in a Bentley Manual.
http://www.amazon.com/BMW-E90-E91-Se...mm_hrd_title_0
It will step you through everything, with photos. It can be a little vague at times and you'll have to use intuition, but none of it is very complex...only time consuming. I'll be happy to answer any specific questions if you get stuck.

[csupernova]

When the starter is about to go bad, does it gives any error on the dash?

[Chriztofor]

god I hate dealers. I agree with the post above, it can't be alternator if battery is fully charged!!! Ugh.

[nilknarf]

Originally Posted by csupernova

When the starter is about to go bad, does it gives any error on the dash?

Unfortunately, No.

[csupernova]

Thanks nilknarf for all the information. Your post contributed a lot.

[mh666]

Thanks nilknarf. I've actually never heard of the Bentley manual before.... which is a shame because it would've made my diys easier at times. I should check it out.

[nilknarf]

Originally Posted by mh666

Thanks nilknarf. I've actually never heard of the Bentley manual before.... which is a shame because it would've made my diys easier at times. I should check it out.

Yes, Bentley is well worth the money spent. This link will search new and used additions and sometimes show available coupons, so you may be able to find it at a better price than Amazon. Good luck!

http://www.addall.com/New/submitNew....C&dispCurr=USD

[mh666]

Thanks for the link!
Will keep you updated should I decide to replace the starter on my own!

[mh666]

Just another question: do you know whether I would be able to work from the top alone w/o having to jack the car up and going underneath?? Because my car's parked in an underground garage with cars parked next to it and that just makes my job a lot harder if I have to jack up the car.

[nilknarf]

Originally Posted by mh666

Just another question: do you know whether I would be able to work from the top alone w/o having to jack the car up and going underneath?? Because my car's parked in an underground garage with cars parked next to it and that just makes my job a lot harder if I have to jack up the car.

You're in luck. Everything is done from the top.

[Ibo24]

I think I have the same issue as you!

When I put in the key in the slot, it gives a sound that the key is in. When I push the start-stop engine button it gives me the dashboard right before it start. So the ignition is on, but the car doesn't start.

Wednesday my car is going to get a big maintenance. But! Since they are going to ask WAAAY more then we could afford... Could you please provide a DIY so my dad and I can work on this one...

[89hatcher]

Damn I think this just happened to me . My battery is fully charged, tried jumping the car but won't turn over. Service engine soon light is on. Gonna try pull the code. Hopefully the starter is the problem.

[ebap990]

I'm in the middle of this job now. I can't for the life of me get a torx socket on one of the bolts that holds the starter (the one closer to the firewall).

Do you remember how you got it out? Did you need to buy a Torx box wrench (I saw a E36 starter replacement video alluding to this, and it looks the same, but I'm hoping there is an easier way.

Ethan

[nilknarf]

Those are the reverse torx, right? I used a reverse torx socket and don't recall having any problem. If the angle was tight, I might have used a universal joint socket adapter.

[F30Mo16]

I think I'm having this problem as well... Sometimes my car struggles to to turn on and 6/10 times has a delayed start... I thought it was the battery so I replaced it the other day but it is still doing it... How can I pull a code to see if its going bad or not? Can I take it to autozone and have them pull it? or do I have to get myself a code reader?

[nilknarf]

Originally Posted by 620BMW325i

I think I'm having this problem as well... Sometimes my car struggles to to turn on and 6/10 times has a delayed start... I thought it was the battery so I replaced it the other day but it is still doing it... How can I pull a code to see if its going bad or not? Can I take it to autozone and have them pull it? or do I have to get myself a code reader?

I have diagnostic software on my laptop (see http://forums.bimmerforums.com/forum...play.php?f=233), but there's a really steep learing curve involved in getting that up and running. I would give autozone a shot and see if they can pull anything. If not, a local independent mechanic should be able to read it for a small fee.

[obert]

Nice info and Bentley is a must if you work on your car yourself

[89hatcher]

attempting to change the starter by myself. needed to buy 2 crankcase vent hose cause mines cracked when trying to take it off.

[89hatcher]

Originally Posted by ebap990

I'm in the middle of this job now. I can't for the life of me get a torx socket on one of the bolts that holds the starter (the one closer to the firewall).

Do you remember how you got it out? Did you need to buy a Torx box wrench (I saw a E36 starter replacement video alluding to this, and it looks the same, but I'm hoping there is an easier way.

Ethan

i took a 12 point 11mm short socket to a 3/8 ratchet to take mines off. you can also try using an 11mm open end. thats what i used on mines and it came off.