ManiacAUS

Hi all,

New to this Forum and looking for a bit of guidance on an issue as my mechanic is stumped.

I have an 06 530i pre LCI.

The problem I'm having is that when I accelerate from a stop, or a very least approaching say a roundabout and need to essentially all but come to a stop, when I give the car throttle of any more than 1/4 throttle then the RPM's fall like the car is either starving of fuel or some other reason.

My mechanic has check and changed all of the following:
1. Software just updated.
2. Vanos replaced.
3. Coils replaced.
4. Plugs replaced.
5. Air intake sensor replaced (apparently some prev goose mechanic had an incorrect part there).

Since all of those were done the car has definitely improved in terms of performance and MPG however the initial problem if the car dropping it's power still remains.

Only happens at low RPMS.
Problem can be replicated in N or P when stationary - ie, does not have any effect on load on the engine etc. A can also hear what sounds like a small miss, or backfire from the exhaust.

Has anyone had this problem before. It's pretty dangerous as the car boggs at low speed, and I'm worried I'm gonna have someone fly up the back of me.

Interestingly enough - before all the above stuff was changed, the car actually stalled a few times because of this.

I also note than this problem does not happen when the car has just been started and is cold when the idle RPM is at about 1000, but only happens when the RPM's come down to the normal idle of 600.

Would really appreciate if anyone can point me in the right direction..

Had some BMW SA try and tell me this is normal for this type of car....I don't know of any car where such a serious and basic fault would be considered 'normal'.

ssalb

What about the Intake Manifold Actuator (DISA Valve). If its not working properly it will cause low RPM drivability issues. Not sure if you looked at that yet.

RealOEM.com BMW E60 530i Intake manifold system

#2 in the diagram.

ManiacAUS

Hi,

No haven't looked at that but i'll look into it.

Do you think a fault there would throw any codes?

The mechanic had a code reader but couldn't locate the fault from the code reader?

Thinking I might spend some cash and buy one. Any suggestions?

buddy

how many miles on the car? does it do it when the car is cold also

ManiacAUS

it's got 62,000 kms on the clock... that'd be around 40,000 miles I guess. does it at all temps. as soon as the idle drops to 600 I have the problem.

rhyary

Throttle positioning sensor.
Other cars will exhibit this behavior with a bad TPS but I am not sure about the E60.
If it has one, it is something to investigate

ManiacAUS

I have read that a dodgy Cam sensor will exhibit these symptoms I described. What do others think? I also read that the Cam Sensor sometimes will not throw a code either... Before I go replacing parts I have ordered a USB - D-Can cable plus software that will hopefully lead me down the right path. Would appreciate any ideas in the mean time and I'll post back with what I find when I get the software.

Cheers.

Stephen Max

The E60 has an electronic throttle with no TPS, but it does have a potentiometer in the accelerator pedal module which could give problems similar to a dead spot in a TPS. Definitely worth looking into.

ManiacAUS

The throttle response and RPM's are fine when squeezing the pedal through the range. It's not so much a dead spot, maybe that wasn't the best way to describe it.. it's more like if I go from 0% to 30% throttle, the revs drop and the car boggs...I have to let go of the throttle and squeeze it through.... do you still think it could be the pedal unit?

Stephen Max

The fact that it operates normally until the engine warms up indicates that it is a problem when engine management goes into closed loop operation. That indicates maybe an O2 sensor problem. Maybe they are sluggish to the point where they can't control the air-fuel ratio fast enough, and the afr goes lean momentarily. Just a thought.