M3 Slow Acceleration

[Stilt]

Hello fellow forum members,

I recently encountered an issue with my M3, and I am seeking some advice to resolve it. While driving, my gas pedal seemed unresponsive beyond 30% input. In other words, no matter how much I pressed the pedal down beyond the 30% mark, the car would still only accelerate as if I was maintaining that level of input.

Additionally, the car feels as if the VANOS system is not functioning correctly. There is no noticeable change in the car's performance when it reaches higher RPMs. The acceleration is sluggish, and the engine sounds slightly off.

I have attempted to reset the throttle adaptations twice, but it did not resolve the issue. I suspect that the problem might be related to the VANOS system or the sensor inside the gas pedal. This suspicion is reinforced by the presence of code B8, which indicates a "Function Inlet Vanos" issue.

For context, I recently performed the following maintenance and service on March 27th:

Replaced both Throttle Position Sensors
Conducted an oil change
Cleaned the VANOS solenoid pack
Cleaned the Idle Control Valve (ICV)
Cleaned the throttle bodies
Installed new intake boots and clamps
Additionally, a few weeks prior to the recent maintenance, I replaced the camshaft position sensor located near the firewall.

I would greatly appreciate any insights or suggestions on how to troubleshoot and resolve this issue. Thank you in advance for your help.


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[Stilt]

Well, new information has come to light and it is now unclear whether one of the POs have done the Vanos or not, but it’s possible they did.

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[jet_dogg]

Hello fellow forum members,

For context, I recently performed the following maintenance and service on March 27th:

Conducted an oil change
Cleaned the VANOS solenoid pack
Cleaned the Idle Control Valve (ICV)
Cleaned the throttle bodies
Installed new intake boots and clamps

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These things do nothing to resolve issues, neither does resetting adaptations not sure why this concept is always propagated on forums.

Regarding the code perhaps some peeps who have been through this will chime in. I can't remember if I got codes when I replaced the solenoid pack with a new one years ago or it just ran like shit.

Also, you could have bad coil packs.

[EthanolTurbo]

Well, new information has come to light and it is now unclear whether one of the POs have done the Vanos. So, that makes sense.


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Better check and make sure they didn't just "inspect" the rear subframe/RACP. Or do a super useful Blackstone oil analysis to make sure the rod bearings don't explode! 😂

[Stilt]

There's records of the rods being done, and I've been under the car so many times doing what ever, that I'm quite familiar with the reinforcement plates.


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[Stilt]

These things do nothing to resolve issues, neither does resetting adaptations not sure why this concept is always propagated on forums.

Regarding the code perhaps some peeps who have been through this will chime in. I can't remember if I got codes when I replaced the solenoid pack with a new one years ago or it just ran like shit.

Also, you could have bad coil packs.

The car was having rough idle issues, which were relieved with the icv cleaning, yes I probably should've boughten one, but I'm impatient.

I'm likely going to order a brand new solenoid pack, hoping that does the trick. But if it is not resolved I'll likely address the full Vanos system and call it a day.


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