Idle Control Valve

[mizuan]

Hi all,Anyone has a problem with the car shuddering and the timing meter goes down suddenly when you want to stop the car (e.g. braking at traffic lights)? I cant leave the gear at D coz it will continue to shudder and need to shift back to Neutral. When shifting back to D, pressing the gas must be done gently or it will stay idle for a while and snap up the 1st gear out of a sudden. Very irritating indeed.Thought its the gearbox but after rebuilding (and being charged RM4300 for it), the same thing happens. Did a computer test and there was no faulty code on the transmission. Tried changing the gear switch sensor (located under the gear shift) but the problem still persist. Now the mechanic suggest that I change the idle control valve (ICV) and the oxygen sensor which will cost me RM600 and RM500 for the parts alone.bimmerforums has this DIY that says you can clean the ICV and put it back again. Anyone has done this or is this the real problem why my M42 engine shudders at low speed?Thanks in advance for all your help. A bit dry on the pockets after raya

 

[E3six]

Doesn't sound like tranmission problem.

A year ago,I have similar problem during idling, clean up ICV, problem solved

 

[mizuan]

Doesn't sound like tranmission problem.

A year ago,I have similar problem during idling, clean up ICV, problem solved

Thanks E3six. Appreciate if you could PM me the place you did the clean-up.

 

[jarance]

Mizuan, when you say "timing meter", do you mean the RPM?

How low did your RPM goes down to before the engine starts to shudder?

If there is no alarm message then it is very unlikely to be the O2 sensor coz
this sensor is monitored by the ECU.

Chances your problem is due to the ICV.

BTW did the engine sometime dies off. Sometime the problem of idling
speed is also due to the vacuum hose. check this item as well.

yes, ICV can be serviced by cleaning it up.

 

[bibendum]

I have that problem & heard that only happens to 318. Changed my ICV for RM600 last year & since no problem. Old one seems to be "leaking air"..

 

[mizuan]

Mizuan, when you say "timing meter", do you mean the RPM?

How low did your RPM goes down to before the engine starts to shudder?

If there is no alarm message then it is very unlikely to be the O2 sensor coz
this sensor is monitored by the ECU.

Chances your problem is due to the ICV.

BTW did the engine sometime dies off. Sometime the problem of idling
speed is also due to the vacuum hose. check this item as well.

yes, ICV can be serviced by cleaning it up.

Jarance,

I was indeed referring to the RPM meter. It went down to below 500 rpm before its starts to shudder but I have never encountered any occasions where the engine dies off. And there were no alarm message as well so I will take it from you to leave the O2 sensor alone then. I'll check the vacuum hose though and I suppose check means looking for any holes if they may appear because of the wear n tear.

I'll get it sent to a mechanic at Batu Caves to see if they can clean up the ICV and will let everyone know if it works.

Thanks a lot.

 

[mizuan]

I have that problem & heard that only happens to 318. Changed my ICV for RM600 last year & since no problem. Old one seems to be "leaking air"..

Bibendum,

That could be the problem...but I still do not understand why it has to happen at low speeds. i can drive all the way balik kampung to A setar and back and everything sounds and works fine at high speeds.

 

[Lionel_Koh]

1st...check all hose to see either got any leaking then clean ur ICV n check ur AFM as well.........

 

[mizuan]

1st...check all hose to see either got any leaking then clean ur ICV n check ur AFM as well.........

Lionel,

Mind telling me whats AFM?

BTW, I may come and see you guys at the Sri hartamas TT this week.

 

[Lionel_Koh]

Lionel,

Mind telling me whats AFM?

BTW, I may come and see you guys at the Sri hartamas TT this week.

AFM=Air Flow meter ........

Glad to hear u coming to join us ......

Hope ur problem will solve very soon....

 

[bibendum]

I suppose is due to the difference in air mixture in low speed, for my case.. Cos while waiting for the new part, my mechanic put gums to fill up the hole & it is working 80% ok...
Even now, once I start my car & engaged in R, the RPM will drop below 500 (if I don't rev)... That is for just a while, then is gone... & no problem with D.

 

[Bmmad318i]

Mizuan,

How is the hoses at the brake servo(the one going to the inlet manifold of the throttle body) and there is a check valve there (made of plastic, maybe brittle already also due for a change) this vacuum hose may be due for a change already.
Had a simmilar problem to yours. Does the idle go low when u press the brakes???

 

[mizuan]

Mizuan,

How is the hoses at the brake servo(the one going to the inlet manifold of the throttle body) and there is a check valve there (made of plastic) this vacuum hose may be due for a change already.
Had a simmilar problem to yours. Does the idle go low when u press the brakes???

I'll have to take a look at the hoses later. I suppose its due for a change as well. Perhaps that will be a cheaper route to changing the ICV (if the problem persist after cleaning them). And yes, it goes low when braking and shudders before going to full stop.

 

[khisham]

...mizuan,

...this problem is a rare occurence but does happen due to wear & tear AND obviously inappropriate servicing...

...send your car for a proper inspection because eventually the car DOES stop during high speed journeys AND your electrics don't work then; ie power steering, brakes & even re-starting the engine after you cruise to a stop.....

...There will also be a burnt smell eventually & the damage to repair will be exciting to the heart...Auto Bavaria can tell you what is wrong, you buy the parts separately & negotiate to pay for the workmanship...it's the best avenue of action...

 

[BlueMixWhite]

I had the same problem, initial i tot it was the ICV. Actually it was the AFM, so please pay some attention to the AFM too. My problem is my AFM's butterfly valve doesnt close back once it open to full.

 

[jarance]

1st...check all hose to see either got any leaking then clean ur ICV n check ur AFM as well.........

M42 engine got AFM?? I thought they already upgrade to MAF for M42. M40 use AFM.

BTW, MAF means Mass Air Flow meter.

 

[Lionel_Koh]

M42 engine got AFM?? I thought they already upgrade to MAF for M42. M40 use AFM.

BTW, MAF means Mass Air Flow meter.

afaik .....m42 still use AFM ......

Btw Mizuan u sure ur car is M42 instead of m43?

M42 is is 16V twin cam .....

 

[jarance]

afaik .....m42 still use AFM ......

Btw Mizuan u sure ur car is M42 instead of m43?

M42 is is 16V twin cam .....

Lionel thanks for the clarification...

 

[mizuan]

Will get the mechanic to check the hoses, ICV, AFM/MAF...thanks guys...i sometimes excite my heart, but with those that do not involve German currency...

 

[mizuan]

afaik .....m42 still use AFM ......

Btw Mizuan u sure ur car is M42 instead of m43?

M42 is is 16V twin cam .....

It is M42.