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UPDATE: up & dowm idle rpm's after alterator replaced

4K views 21 replies 2 participants last post by  swampX3 
#1 · (Edited)
Gents, i have a idle issue after replacing the alternator on our '07 X3 w/137k miles. The original alternator was making bearing noise, took it to a rebuilder, it has spun the bearing on the shaft & tgey couldn't find a replacement rotor & so couldn't rebuild it. I ended up buying the low cost rebuilt one from O'Rielleys. Tge car sat for about 5-6 days with the battery disconnected while i was waiting on the replacement to arrive. Had to hook up a battery charger to the under hood electrical posts to open tge rear hatch. Connected tge ground after installing the rebuilt alternator, with the charger still connected. This may have been a bad choice on my part. When i first started it up, i had tge typical BRAKE & 4X4 cautions on dash display, whick went out after rolling up the drive. Had a strange OIL light come on, whick went out when i pressed the check oil button. However during tge test drive, the transmission shifted crappy, haunting for gears. Also, went in to a limp mode for a while. This did tge same on a 2nd drive. I disconnected both + & - at battery, touched tgem together to drain any lingering charge anywhere, kept dusconnected for about 30 mins. Reconnected & test drove, transmission shifting was "normal".
However, i have a up & down idle now. From about 600 rpms to 1000 & back down. It's not in any kind of rythem but still happens after 6 mile test drive. I'm not sure if these are related to the new alternator or not. Anyone see this before?
i opened tge rear hatch & checked voltage at the battery & will get a fluctuating readout. From 15V to 13.x and notice the rear courtesy light go dim & bright as the voltage is fluctuating. The battery is 3 years old & showed 12.4 v when the engine was not running & disconnected which is a little low.
could the voltage regulator on the rebuilt alternator be causing this?
I welcome all replies.....
 
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#2 · (Edited)
15volts is ok

if you actually have 15 volts it maybe just under max .....double triple check your readings.....high levels of volts can smoke stuff and cause many gremlins....see the readings of 15.5 volts max in the next post eric the car guy video.....I had to edit this post cause I first read eighteen volts and not the 15 volts you typed

also ....get a 50 buck c110 code reader like joylove always recommends or get your codes read for free at the auto parts store and report back
 
#5 ·
Had O'Rielley's check the alternator & they said it was bad; that the tester was showing bad diode(s) so they ordered me another one. He was telling me that a low battery can blow a diode & to make sure that I had a good charge on the battery.
 
#7 ·
good news on finding the bad actor.....still best to have the codes to ensure nothing else impacted.....how about talking to O'reileys ????....get them to pull the codes.....down here they do it for free
I have a code reader but i don't have any dash lights on, so if I'm thinking correctly, there aren't any codes stored. Will need to hook up my scan soft on lap top to see if any module has any codes.

Replacement alternator came in this morning & i had them check it before taking it & it tested bad. They have oreder another one to be here in the morning plus 2 others to be here Monday. I have a bad feeling about these O'Rielley rebuilt alternators.
 
#8 ·
Any help on the up & down idle question?
i have read about tge DISA valve causing this or the round PVC valve on the valve cover also a possibility.

Any comments on this? Also, I can't find the DISA valve on the N52N engine (07 3.0 is) where is it on the intake plenum? I took off the air box & connector tubes all tge way to the throttle body & don't see it. Couldn't find any videos on youtube for this model.
 
#9 · (Edited)
Disa .....aint der no more ??????

put the last seven of your VIN in this realoem.com link and see what you have ....looks like there aint no disa on this 2007 lci example.....(both disas are shown on the outside and inside of the drawing of the intake.....lightly shade part nos 2 and 3..... but the part nos do not show in the list.....but..... you'll know for sure if you check realoem and call bavauto/pelican etc etc.....they have a deeper parts book and get the info immediately.....best wishes and report back.....DO NOT BUY ANY PARTS WITHOUT YOUR VIN VERIFYING THEY FIT YOUR X !

http://www.realoem.com/bmw/enUS/showparts?id=PC73-USA-04-2007-E83N-BMW-X3_30i&diagId=11_3756
 
#10 · (Edited)
N52 tech info

they show the 3 stage disa for the N52 bmw engine in this....especially pages 42 and 43 ....they show the newer electricaly operated disas on the inside and outside of the intake manifold

"The intake manifold is manufactured from lightweight thermo-plastic. The manifold provides the mounting for the 2 airflap actuators for the three-stage DISA system as well as the electronic throttle flap actuator."

http://www.kneb.net/bmw/E90/04_N52 Engine.pdf
 
#13 ·
they show the 3 stage disa for the N52 bmw engine in this....especially pages 42 and 43 ....they show the newer electricaly operated disas on the inside and outside of the intake manifold

"The intake manifold is manufactured from lightweight thermo-plastic. The manifold provides the mounting for the 2 airflap actuators for the three-stage DISA system as well as the electronic throttle flap actuator."

http://www.kneb.net/bmw/E90/04_N52 Engine.pdf
Thanks for the info swampX3.....Good stuff here. Thanks to this information, I located the larger actuator (DISA?) P/N 11617579114 that is just above the TB. I removed it & YES the flap is toast. The top pivot is sloppy plus the flap will move 90 deg. easily, which tells me it is not connected internally to the gear actuator & basically doing nothing. See the below video.
https://youtu.be/3QkFI9LtmFA
I can only ASSUME that it is the cause of the oscillating idle (500 to 1000 rpms) CAN YOU VERIFY THIS TO ME?
So now I feel I need to replace this Adjuster Unit P/N 11617579114. I found one on ebay for $225 from a BMW dealership with free shipping. MRSP is $355. Even with my employee discount, I can not purchase this part that cheap; maybe $284 + tax at best.
I have not looked at the "Top Adjuster" 11617560538 at this time, so it may be shot too.

Do you feel this is the main cause of the irregular idle? Have others fixed it by this replacement part? I have not found any other info other than this video & what ESC says in their add. http://www.ecstuning.com/Search/11617579114/ES25849/

Thanks,
 
#12 · (Edited)
good n52 intake/disa location images

http://www.e90post.com/forums/showthread.php?t=37444

click to change vehicle Showing products for 2007 X3 3.0si

(click to see more)
Intake Manifold Actuator - Intake Manifold To Cylinder Head - Genuine BMW
This item is often referred to as the DISA ... more info...
Part # : 11 61 7 560 538 $ 337.95
...................................................................................................................
no image
Intake Manifold Actuator - Throttle Body To Intake - Genuine BMW
This item is often referred to as the DISA ... more info...
Part # : 11 61 7 579 114 $ 337.95
...................................................................................................................
 
#14 · (Edited)
bad disa = bad idle/overall performance

its well know that bad disa's cause idling issues.....(disas and vanos solenoids possibly run neck and neck for idle issues) and ....you have to pop the intake manifold off to get to the inner one.....let's hope you can resolve the challenges with good volts and good disas.....don't forget to run the codes again
 
#15 ·
its well know that bad disa's cause idling issues.....(diss and vans solenoids possibly run neck and neck for idle issues) and ....you have to pop the intake manifold off to get to the inner one.....let's hope you can resolve the challenges with good volts and good disas.....don't forget to run the codes again
SwampX3.........just thought I'd follow up on on the "adjuster valve/disa"; below are pics of where it lives for others to see & what a bad one looks like. I moved the flap to the opened position to show what it shouldn't do. It's my understanding that the flap should be closed in the default position & can not be able to move at all by hand.
 

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#16 · (Edited)
great images

excellent images and feedback .....best wishes and thanks....keep us posted on how it all comes out

the other disa is under the manifold ......the problem that shops with the ability to actuate these disas have, is that they can't be sure of the mechanical condition of the flapper etc like a good eye ball inspection can do......so .....many times its tough to beat a physical looksee

there are several critical parts like this that we believe should be swapped out based on time and mileage cause the failure modes can be catastrophic such as big pieces being ingested into the cylinders.....then Kaboom.......same for the CCV system oil ingestion failure mode
 
#17 ·
Thought I would post pictures of the new unit (Adjuster Unit P/N 11617579114) that just came in today. The flap is not moveable (tight) unlike the old bad one. Also, the top shaft hole is a good fit with the steel shaft, unlike the old one. Part is OEM BMW, purchased from BMW of Atlantic City off ebay. Best price ($224.26) free freight & no tax.

I have already installed it & replaced the (2) rubber/plastic extensions from the Valve Body that need to be removed to get to the Adjuster. Took all of 10 mins. TIP: lube the seal surfaces of the adjuster & both VB extensions with clear mineral oil to allow/aid them back into place. Makes it so easy.

Waiting on the used alternator to come in. Once that's installed I'll report back as to the idle issue. Need the alternator before I can crank it up.

Let me know if anyone has any questions that I may help with.
 

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#19 ·
OK...used Alternator came in today; 180AMP instead of 150AMP that was on the car. HOWEVER, the plastic connector was broken on the new used one. NOW what? I ended up removing the original regulator from the 150 amp & installed it on the new used one. Everything seems to work OK at this point. Idle is good too (with new adjuster valve/DISA)
Does anyone know what issues I'll have with a voltage regulator from a 150amp on the 180amp alternator?
 
#20 · (Edited)
should be ok

you will need a tad more hp from your engine to drive a 180 amp but not much cause the loads you supply from the alternator are not changed .....as long as it fits OK and the regulator does its job it will be good on the older non computer controlled ones ....also .....great to hear things have smoothed out

PS .....the drive pulley gotta be good .....did you give it a good spin ??????
 
#21 ·
you will need a tad more hp from your engine to drive a 180 amp but not much cause the loads you supply from the alternator are not changed .....as long as it fits OK and the regulator does its job it will be good on the older non computer controlled ones ....also .....great to hear things have smoothed out

PS .....the drive pulley gotta be good .....did you give it a good spin ??????
SwampX3...thanks, that's what I was thinking.

Question: are you saying the 150amp alternator is not "Not computer controlled". Both regulators are identical except for the P/N printed on the back. Both receive the 2 pin connector. I thought the higher AMP output was the only difference, which would actually be more windings in the stator wouldn't it?

Yes, the drive pulley felt OK, same as the old one. I'll keep it as a spare, as well as the stator. I don't think the rotor is salvageable. Maybe I'll try taking it apart so I can learn how to replace the bearings next time.
 
#22 · (Edited)
don't think either are computer linked

yes ....there will be more mass in the bigger amp one .....also very unlikely any of the older alternators were ever hooked to the bus system/computer unless one came off an advanced model.....many of the newer systems have overrunning clutches etc on the alternator drive to limit engine loading when not required....also ....many come with smart field loading/monitoring

no matter what you have.... it's the simple diodes and regulator electronics that control your output from the alternator.....your wiring diagram would tell you if it was hooked to an independent bus to computer system module on your vehicle

the main happiness is that you've got a good physical fit/no overheating/cables fit/regulator is letting out max of 15.5 voltsish/pulley and belt are happy/car runs good

with all those amps you could hook up a rack of spot lamps and go rally driving.....but ....then we get into conductor/cable sizing/circuit protection etc etc
 
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