E39 jerk and brief no response when full throttle on 1st gear

[Psykit]

Hi everyone,

Some update and further advice needed on this topic. Please read on what was replaced recently: http://www.bmwclubmalaysia.com/forums/showthread.php?47970-Workshop-in-Penang&p=807039&highlight=#post807039

Basically, I replaced the oil separator (CCV) and 4 connecting hoses to no avail. It still has jerks during take off from idle standstill. A fault code (Gear Monitoring) logged on GT1 was present and my regular mechanic suggested a gearbox rebuild. Something to do with the torque converter ball valve.

What I need advice from you folks is what could cause a vibration pattern (not a harsh one but prominent and abnormal) at idle only when warm with constant RPM reading of 740-760rpm? Engine and transmission mounting were replaced a few months ago as well as fuel filter, spark plugs and all ignition coils.

Before and after the oil separator and 4 hoses replacement, the car has developed this pattern of vibration pattern. Something that is on and off, on and off kind of vibration that can be felt from the dashboard, steering, basically the whole car. Car is now scanned without any fault codes. The vibration is only present when car is operating at operating temperature.

Also the feeling of loss throttle, and I can recall this happened to me countless times is when you are at a busy junction waiting for a chance to cross, you found one and hit the throttle down to go fast. All of a sudden RPM went down slightly and no throttle for a brief moment of 1 second, then all of a sudden power came back. Scare the hell out of me

Throttle body was clean, Idle Control Valve (ICV) was clean as well. Both made no improvements.

Any advice, pointers are greatly appreciated. Thank you.

 

[haywire]

Have you considered the Control Unit (DISA valve)? Its a common fault too with the flap.

 

[Psykit]

Have you considered the Control Unit (DISA valve)? Its a common fault too with the flap.

Opened up and checked the DISA adjuster unit too. No problem with the flap, pin still intact, vacuum pot still works fine and I have placed some RTV on the O-ring as well to ensure a tight seal.

No difference after that.

 

[huskar3399]

ICV controls the idling.
DISA controls your low end performance.

but you had checked both to be in good state and now i wonder what else to check.

i had the same experience as yours, car vibrates badly not only during idling but also at low speed. there was once when i started moving to cross a T junction, the engine was badly shaking and it went off and i had to restart the car. this happened several times to me. but after i cleaned the ICV, the problem just disappeared. during cleaning the ICV did you try wiggle it and see whether the tiny flap/valve playing? because good ICV should have the flap playing.

for DISA did you glue it back to when you reinstalled it?

 

[Psykit]

ICV was clean and flap has free play too. Shouldn't be the ICV. Idling was fine, RPM reading is steady. But can feel vibration pattern.

DISA flap was in good condition. The seals are worn but RTV sealed it nicely with the manifold when reinstalling it.

Any possibility of O2 sensors? Anyone replaced O2 sensors and see improvements in terms of hesitation and vibration?

 

[huskar3399]

ICV was clean and flap has free play too. Shouldn't be the ICV. Idling was fine, RPM reading is steady. But can feel vibration pattern.

DISA flap was in good condition. The seals are worn but RTV sealed it nicely with the manifold when reinstalling it.

Any possibility of O2 sensors? Anyone replaced O2 sensors and see improvements in terms of hesitation and vibration?

i replaced both of my pre-cat o2 sensors with new ones but feel like nothing improves.

 

[Psykit]

No improvements on fuel consumption and standstill acceleration?

What was your initial issue bro huskar?

 

[huskar3399]

No improvements on fuel consumption and standstill acceleration?

What was your initial issue bro huskar?

at first my car was OK. then this CEL came out after i replaced my vanos seal. vanos replacement gave me some feeling of increased performance but at same time my engine started to vibrate and choke. i replaced MAF sensor, 6 ignition coils, 2 pre-cat sensors, and recently the CCV. all of them are new. i also cleaned my ICV and DISA but the CEL is still showing. no idea where else to check so i suspect post cat sensors or the CAT itself are bad. i still hold on not to change that before i got more justifications.

 

[Psykit]

Have you tried injector cleaner? Or maybe remove injector and ultrasound clean it?

I have tried to pour in injector cleaner but made no difference.

 

[huskar3399]

Have you tried injector cleaner? Or maybe remove injector and ultrasound clean it?

I have tried to pour in injector cleaner but made no difference.

no i haven't. i saw one vendor here is selling liqui moly jet cleaner. should give them a call if i plan to do the cleaning.

 

[tweiboon]

Hi everyone,

Some update and further advice needed on this topic. Please read on what was replaced recently: http://www.bmwclubmalaysia.com/forums/showthread.php?47970-Workshop-in-Penang&p=807039&highlight=#post807039

Basically, I replaced the oil separator (CCV) and 4 connecting hoses to no avail. It still has jerks during take off from idle standstill. A fault code (Gear Monitoring) logged on GT1 was present and my regular mechanic suggested a gearbox rebuild. Something to do with the torque converter ball valve.

What I need advice from you folks is what could cause a vibration pattern (not a harsh one but prominent and abnormal) at idle only when warm with constant RPM reading of 740-760rpm? Engine and transmission mounting were replaced a few months ago as well as fuel filter, spark plugs and all ignition coils.

Before and after the oil separator and 4 hoses replacement, the car has developed this pattern of vibration pattern. Something that is on and off, on and off kind of vibration that can be felt from the dashboard, steering, basically the whole car. Car is now scanned without any fault codes. The vibration is only present when car is operating at operating temperature.

Also the feeling of loss throttle, and I can recall this happened to me countless times is when you are at a busy junction waiting for a chance to cross, you found one and hit the throttle down to go fast. All of a sudden RPM went down slightly and no throttle for a brief moment of 1 second, then all of a sudden power came back. Scare the hell out of me

Throttle body was clean, Idle Control Valve (ICV) was clean as well. Both made no improvements.

Any advice, pointers are greatly appreciated. Thank you.

Gear oil enuf ?

 

[Psykit]

I'll get the mechanic to check that during my next service. I have read something on this as well. Said that could be some trapped air inside the transmission or maybe insufficient oil.