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-   -   My 745li is idling up and down at 1500 rpm (http://www.bimmerfest.com/forums/showthread.php?t=655421)

los2much 11-01-2012 09:27 AM

My 745li is idling up and down at 1500 rpm
 
It dont idle like this when sitting in park but only as you going down the road and its at 1500rpm where it goes up and down. If anyone ever experienced this please help me out on the fix and please be detail thanks.

SFbay 11-01-2012 10:06 AM

Quote:

Originally Posted by los2much (Post 7169962)
It dont idle like this when sitting in park but only as you going down the road and its at 1500rpm where it goes up and down. If anyone ever experienced this please help me out on the fix and please be detail thanks.

It's your tranny acting up.

Khabar 11-01-2012 10:18 AM

I think it maybe flywheel getting stock.

los2much 11-01-2012 10:20 PM

it has no problem changing gears

Khabar 11-02-2012 08:48 AM

I know I have the same problem. it happens only when it time for trans to downshift,but if u use manual mode it work just fine. Take a look at flex disk maybe it broken

BimmerBrad7 11-02-2012 10:56 AM

My car does exactly the same thing. Its pretty annouying. Same as you tranny shifts smooth as silk. But if im coasting down the road foot off the gas the rpms will go up and down slightly. Can't figure it out.

los2much 11-04-2012 08:53 PM

I wish some experience techs would chime in.

MR 7 11-12-2012 06:28 AM

Try the infamous PCV valves or also known as crank case ventilators. I have attached a link so you can see what they look like

http://www.ebay.com/itm/OEM-BMW-E53-...-/160688315458

Khabar 11-12-2012 08:10 AM

It is good thing to change them but it has nothing to with the problem

Bryanycw 11-14-2012 09:41 PM

Hello, I have same problem even changed MAF Sensor....really annouying, hope can have some suggestion & solution here.

cmpcpro 11-14-2012 11:30 PM

I have same issue, only when car is cold.. for first few minutes of driving, if it drops down to 1200rpm or so it will move up and down, after it warms up its gone.. I first thought tranny, but I am wondering it it has to do with motor.. I think maybe motor is not running at 100% and is making the tranny shift "off" maybe a little power short? who knows, really discouraged with these cars after reading nothing but problems with everything..

cmpcpro 11-15-2012 04:39 PM

Quote:

Originally Posted by SFbay (Post 7170050)
It's your tranny acting up.

Well I have been having this issue every morning when I take the car out of the garage.. It happens for the first mile or so then goes away.. I couldn't tell if it was the tranny acting up or the motor running weird.. well today I threw it in M mode while going down the road in 5th having the issue and it remained, it's not the tranny shifting/searching, it's something with the motor. Now I don't drive hard, but I have no idea how the PO drove.. anyway, I noticed when I fired it up the other night when it was cold I could hear the exhuast while I was leaning in the trunk and it sounded a tad bit rough and I think I could smell a little fuel.. anyway, since then I have replaced the stock plugs which were shot with new Iridiums. The coils look to have been done around 07 because they all had an 07 date (MM/DD/YY) of the same 07 date.. I took the MAF out the other night which looked brand new, but I cleaned it anyway.. any other ideas?? Thanks guys!!

DFEL750I 11-15-2012 06:41 PM

Guys if this is not happening when idling in neutral or when stopped in drive and is only happening when the car is coasting then its your torque converter. Check fluid level in the tranny...if it is properly filled then if you want to fix this issue then the torque converter has to changed.

Basically when the engine is not under load and the car is allowed to coast the wheels are freely spinning and the driveshaft is moving faster than the engine flywheel. The torque converter is responsible for doing torque manipulation to counteract that speed difference and keep the engine RPM constant. When the torque converter is not working right it will not do its job properly and therefore you will have the idle fluctuate.

cmpcpro 11-15-2012 07:18 PM

This is not happening when at idle or coast.. When the car is cold for the first mile or so if you give it throttle everything is fine, but if you are feathering to stay at speed limit the tranny will drop into such a high gear the car will run at 1200RPM, and that is when I am getting the fluctuation.. while giving it throttle, if I let off gas then it goes away..

blakey2000 02-11-2014 08:52 AM

me too
 
Did anyone ever figure this out? same issue . Car lightly surges up and down while triving, it shifts fine. Doesnt do it until warmed up. blakeyatwork@yahoo.com any ideas?

It isnt throwing any codes....

2003 745i

ssdriver27 02-11-2014 11:13 AM

Quote:

Originally Posted by DFEL750I (Post 7197609)
Guys if this is not happening when idling in neutral or when stopped in drive and is only happening when the car is coasting then its your torque converter. Check fluid level in the tranny...if it is properly filled then if you want to fix this issue then the torque converter has to changed.

Basically when the engine is not under load and the car is allowed to coast the wheels are freely spinning and the driveshaft is moving faster than the engine flywheel. The torque converter is responsible for doing torque manipulation to counteract that speed difference and keep the engine RPM constant. When the torque converter is not working right it will not do its job properly and therefore you will have the idle fluctuate.

My guess is what he said. That or pvc related or vaccum related.

oldknife 02-11-2014 11:34 AM

I just dropped my car off at the shop for this issue, I changed ccv and new plugs.
Going to have the fuel filter replaced as well ... maybe its a coil or a injector or MAF.
I hope they figure it out. Will let you know what they discover.

oldknife 02-11-2014 03:58 PM

video <<<<----Click Here

The car definatly responds better ... now when i park it the revs still bounce up and down but not like before ... included a video.

The fuel filter did the job ... and no codes came up ... lets see if it acts up tomorrow morning.

Joe750 02-11-2014 04:35 PM

I have the same issue ! Never made a big deal about it but it does bug me !


Sent from BimmerApp mobile app

ericesquire 02-25-2014 10:09 AM

Quote:

Originally Posted by oldknife (Post 8139195)
video <<<<----Click Here

The car definatly responds better ... now when i park it the revs still bounce up and down but not like before ... included a video.

The fuel filter did the job ... and no codes came up ... lets see if it acts up tomorrow morning.

What's the latest?

oldknife 02-25-2014 01:29 PM

It is still happening, but I have been trying to keep a daily OBD2 log.
with Blue Driver & Iphone
Will do a review of the tool BlueDriver vs the Elm later.
No resolution yet also ... been occupied with quarterly taxes, buying car for son and tires & rims for the e65. Suspension next and go back to mechanic with all my data and video.
Thanks for asking

Busarider 02-26-2014 01:02 PM

It seems that car has learnt drive adaptations from the previous owner, try resetting your transmission using the method described in the forum first.
Does this happen when you use diffrent set of keys? has the software been updated for the transmission? check with the dealer.

CarFanatic 02-27-2014 12:39 PM

i had the same issue , have the dealer run the code you'll have a misfire and usually you need to have the head replaced . I had mine replaced and its perfect but remember if you do nothing about it. it gets a lot worse :( literally my car would galap ...

erniejazz 03-07-2014 01:55 AM

I have the same issue cruising at 38-40 mph. Having the Maf cleaned, new fuel filter, new air filter, new ccvs.... should have it back tomorrow. Also new battery and registration. Hoping this helps. Secondary air was very dirty so maybe choking a bit. Cleaned that using the AGA tool. Who knows.

los2much 03-07-2014 05:06 AM

have anyone figured out the fix for this problem?


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