Loss of Acceleration and Wobbly Idle Speed

[mysticsysta]

Hi Guys,
Hope someone can shed some light on what I just went through... I am driving an 05' E90. Just had a spirited drive up and down Tuas expressway and back to office. On returning I noticed that when moving off and at slow speeds the car seems to have lost acceleration power. When Idling the whole car seems to wobble slightly (as if the engine is gg to die but it nvr does).

Also has an air compressor problem before this, which I have not fixed yet, where the aircon takes forever to become cool unless I rev really hard. but in start stop traffic the aircon temp becomes hot again ( like theres no aircon gas)

Wondering if its a new problem or its connected to the compressor?

Anyone has this problem too? Kindly share TQ!

 

[astrid]

Re: Loss of Acceleration and Wobbly Idle Speed

I think its your 6-yr old Valvetronic stepper motor giving problems to your TDC detonation. Get PML workshop to do combustion cycle mapping. Worst case, may need to replace the Valvetronic motor.

Air compressor??? You mean you have a supercharger lupped to your NA engine? :thinking:
Or you mean air-cond compressor? :laughlik:

 

[pengful]

Re: Loss of Acceleration and Wobbly Idle Speed

You did not state which model of E90 but if it is a 320i, I can share some acquired knowledge.
1) Loss of acceleration power - Likely valvetronic motor giving problem. Though you can still drive, expect it to break down completely around 4-6 mths.
2) Wobbly rpm - If it fluctuates up and down during idle or waiting, most likely cause is the ignition coil.
3) Air con compressor and air compressor are different things.

 

[wt_know]

Re: Loss of Acceleration and Wobbly Idle Speed

the infamous valvetronic motor, ignition coil lifespan is about 100k milleage?

 

[mysticsysta]

Re: Loss of Acceleration and Wobbly Idle Speed

Hi All,
Thanks for the information and sharing everyone... yes its a 320i. And yes I meant air (con) compressor. Anyway couldn't take it anymore so went to my mechanic and got it solved over the weekend. It was actually the Hi Tension Coil that needed replacing. After that everything worked fine.

 

[chinweyngee]

Re: Loss of Acceleration and Wobbly Idle Speed

Hi All,
Thanks for the information and sharing everyone... yes its a 320i. And yes I meant air (con) compressor. Anyway couldn't take it anymore so went to my mechanic and got it solved over the weekend. It was actually the Hi Tension Coil that needed replacing. After that everything worked fine.

what problem did the Hi Tention Coil solved?

 

[mysticsysta]

Re: Loss of Acceleration and Wobbly Idle Speed

loss of acceleration and wobbly idle speed

 

[TCcruiser]

Re: Loss of Acceleration and Wobbly Idle Speed

I also has the problem of wobbly idling. However, it only occurs when I'm in Park (P)or Neutral (N) mode. When I'm on Drive gear, it is ok. Anyone can advise what is the problem?

 

[Lorinser]

Re: Loss of Acceleration and Wobbly Idle Speed

I also has the problem of wobbly idling. However, it only occurs when I'm in Park (P)or Neutral (N) mode. When I'm on Drive gear, it is ok. Anyone can advise what is the problem?

can be many possibilities
1. ignition coils
2. plugs
3. air-oil separator (choking the vacuum which is needed inside crankcase)... i changed this
4. air mass sensor... i changed this
5. fuel system
and so on..........

go see a mechanic is the best solution

 

[Jarren]

Re: Loss of Acceleration and Wobbly Idle Speed

You did not state which model of E90 but if it is a 320i, I can share some acquired knowledge.
1) Loss of acceleration power - Likely valvetronic motor giving problem. Though you can still drive, expect it to break down completely around 4-6 mths.
2) Wobbly rpm - If it fluctuates up and down during idle or waiting, most likely cause is the ignition coil.
3) Air con compressor and air compressor are different things.

Good explanation! But what is the est. damage for valvetronic motor or ignition coil?

Will the E90 325i likely to have this problem when come to that mileage??

 

[detach8]

Re: Loss of Acceleration and Wobbly Idle Speed

My old E90 had slight fluctuations in RPM while idle. TUrns out to be the sparks... the original plugs had been in the car for 5 damn years.

Anyway, I'd suggest don't think too much and just drive the car. When time comes, it will come. The more you think of it, the faster your blood pressure go up...