Unstable Engine Power

[kw930]

Has been driving my 320i (M54B22) for the past 1 year, so far quite some services had done to keep maintaining the car performance as per original as possible. Overall the car has been improved a lot as compare to a year ago, but still 1 issue that's quite frustrating and may need to seek the advice from sifu here.
The problem I'm facing is the car having unstable engine performance, which during morning start up and after the first few minutes of driving, engine normally very responsive, pickup normal and the engine revving sound very solid. However, after a while, especially after stopping at junction or traffic light then re-pick up again, you may hear very loud roaring sound from engine and the car pick up slow. May need to step the pedal to rev higher, keep on driving some distance then the power may resume and engine revving sound back to normal. Observe the problem also happen when driving for some distance during hot whether, engine may suddenly roar out load and lack of power.

Base on last scanning result (using scanner 1.4), no any significant error found.
What had service and changed so far are :

1) Double vanos o-ring & seal
2) All new spark plugs and ignition coils
3) Gear box oil changed
4) Hardened vacuum hoses inside throttle body changed
5) New fuel pump & filter
6) New oxygen sensors
7) Adjuster unit (DISA)

Wonder would this unstable engine performance related to mechanical, electrical (sensors?)or pneumatic (vacuum?)?
Besides, also suffering high fuel consumption all this while (around 13.5l/100km), not sure related to this issue too?

 

[jarance]

Try to clear the adaptation for the gearbox.

 

[antiquer]

Try to clear the adaptation for the gearbox.

How to do that bro jarance?

 

[kw930]

Yup, how to do it bro?

 

[jarance]

You have to use INPA program.

Load INPA and select your model. In my case "F3" for E46. Go to menu and select "Transmission"

It will pop up the type of gearbox module. Select the correct module.

Check the error message and note down the error code if any. It will help to discuss with other.

Goto 'Activate" menu and select "adaptation reset".

Adaptation reset is just to clear all the previous setting so that the GBox will learn again.

 

[kw930]

Found a thread on this forum : http://www.bimmerfest.com/forums/showthread.php?t=261285
"Turn on the car such that all the accessory lights are on but the motor is not running, depress the gas pedal all the way to the floor, keep the pedal there for 30 seconds and the transmission will reset to the original factory settings (it will "unlearn" the adaptive settings)."

Will it work on our E46?

Another thread also discussing about it, but with different method :
http://forum.e46fanatics.com/showthread.php?t=760867

 

[jarance]

Found a thread on this forum : http://www.bimmerfest.com/forums/showthread.php?t=261285
"Turn on the car such that all the accessory lights are on but the motor is not running, depress the gas pedal all the way to the floor, keep the pedal there for 30 seconds and the transmission will reset to the original factory settings (it will "unlearn" the adaptive settings)."

Will it work on our E46?

Another thread also discussing about it, but with different method :
http://forum.e46fanatics.com/showthread.php?t=760867

No harm trying..

 

[Herbert]

Symptom of car losing power after warming up would likely be worn out auto clutch plates.

 

[moots]

The problem I'm facing is the car having unstable engine performance, which during morning start up and after the first few minutes of driving, engine normally very responsive, pickup normal and the engine revving sound very solid. However, after a while, especially after stopping at junction or traffic light then re-pick up again, you may hear very loud roaring sound from engine and the car pick up slow. May need to step the pedal to rev higher, keep on driving some distance then the power may resume and engine revving sound back to normal. Observe the problem also happen when driving for some distance during hot whether, engine may suddenly roar out load and lack of power.

bro...from your description....and from what I have read,the e46 m54 uses the mechanical viscous coupled fan and it looks like your fan clutch is clutching at the slightest of overtemp.The roaring sound is the sound of your fan.The underpower is due to the drag of the fan.When stopped at traffic,at increased temps,the clutch engages and when at cruise,when air cools the bi metallic strip on the fan clutch,it disengages,fan freewheels and power is restored.

You need a new fan clutch.

If you have an electric fan...then disregard what I have written.

 

[tweiboon]

I think my wired PDA can clear this gearbox error

 

[kw930]

Symptom of car losing power after warming up would likely be worn out auto clutch plates.

The power lose is happen intermittent, if clutch plate worn out will be happen continuously, right?

bro...from your description....and from what I have read,the e46 m54 uses the mechanical viscous coupled fan and it looks like your fan clutch is clutching at the slightest of overtemp.The roaring sound is the sound of your fan.The underpower is due to the drag of the fan.When stopped at traffic,at increased temps,the clutch engages and when at cruise,when air cools the bi metallic strip on the fan clutch,it disengages,fan freewheels and power is restored.

You need a new fan clutch.

If you have an electric fan...then disregard what I have written.

Think mine is an electric fan, some more it's not always happen during stop & pick up.

I think my wired PDA can clear this gearbox error

Thanks bro, will need to find you out yum cha some day


BTW, had tested the method yesterday according to one of the thread method :
"Turn the key to position "2". Position "2" is one position before the car engages and starts.
Wait 10 seconds and then turn the key back to position "0", which is the initial position.
Once again wait 10 seconds and then start the car up."

Not sure is it physiological feel or it really work, I can feel the different with gear switching more responsive and also don't hear significant load engine roaring. However, so far only try some short distance drive, will keep monitoring.

 

[Herbert]

that is the usual symptom of worn out clutch plates or about to be worn out. also possible torque converter failure. i have a spare m54 torque converter and can loan it to you to try it out.

The power lose is happen intermittent, if clutch plate worn out will be happen continuously, right?


Think mine is an electric fan, some more it's not always happen during stop & pick up.


Thanks bro, will need to find you out yum cha some day


BTW, had tested the method yesterday according to one of the thread method :
"Turn the key to position "2". Position "2" is one position before the car engages and starts.
Wait 10 seconds and then turn the key back to position "0", which is the initial position.
Once again wait 10 seconds and then start the car up."

Not sure is it physiological feel or it really work, I can feel the different with gear switching more responsive and also don't hear significant load engine roaring. However, so far only try some short distance drive, will keep monitoring.

 

[kw930]

that is the usual symptom of worn out clutch plates or about to be worn out. also possible torque converter failure. i have a spare m54 torque converter and can loan it to you to try it out.

Thanks Herbert, let me monitor first, if needed will contact you then.