[hereforbeer]

Hello everyone!

After getting my jumped timing chain fixed I now have some problems on my car. The idle is unstable, and i can feel vibrations in my cabin. Also when I am taking off from a stop, or press the accelerator >50% i can feel it stuttering and almost choking so I have to take off really gently. When i get to speed, everything works fine and there is no loss of power or such.

No fault codes. In the last 500km i have replaced the MAF, Air filter (Improved the idling by A LOT), all the plugs and a faulty coil so far. I have scratched my head on this issue a couple of days and have no clue where to start digging. Oh and I have INPA and ISTA available.

 

[Bali]

What year and model E46?
rant: I don’t understand why people aren’t including that information in their user info or posts.

Start by looking at the fuel trim and MAF values at hot idle. That will tell you if fuel management is running lean or rich, etc.

Did you use a genuine BMW or Bosch brand MAF sensor? Aftermarket sensors for BMWs are usually junk.

 

[MrMCar]

Me either, makes me nuts.
How can we help w/o knowing that.

Please share what was involved in fixing the jumped timing chain.

 

[hereforbeer]

Sorry for the missing information.The car is a -03 Sedan 316i automatic, with 112k miles.

The MAF is from BOSCH.

The chain was fixed at a local auto repair shop, and was told there the chain was off by 2 teeth and they realigned it. (Don't remember if they mentioned anything about the tensioner/guide , I'll have to ask).
I previously had poor performance/rattling noise/sensor fault codes which got solved after the timing procedure. Repair history indicates the car had the complete timing chain work done at a repair shop ~10k miles ago by the previous owner( Could the chain be misaligned this whole time? IDK, only had the car for a 1k miles or so) Will check the fuel trim values tomorrow.

 

[randy72877]

Timing chains don't just jump out of time. It is always caused by something such as a broken guide, bad tensioner or worn chain. The cause of the timing issue must be corrected or it will happen again. Also do a compression test. Incorrect cam timing can cause pistons to hit valves.

Sent from my S61 using Tapatalk

 

[Cvariable]

I have pretty much the same two problems as OP with my N42, actually.
I suspect that at least the rough idle might have to do with the eccentric shaft sensor:
If you unplug the eccentric shaft sensor (a plug to the right of the first ignition coil), it should send the valvetronic system into emergency mode and basically disable it.
On mine, the engine sound / behaviour doesn't really change when doing that. Does the same happen on yours?
I also have oil in the plug connector so i'm fairly certain that the eccentric shaft sensor is part of the problem.

I have now ordered a diagnostic cable, i'll come back here once i find any valuable info.

 

[MrMCar]

Unplugging the eccentric sensor does not place it into emergency mode. Rather it places the eccentric shafts into max lift position. Bringing idle lift from about .2 mm to .8
We often unplug the sensor for diagnostics, as it gives greater lift and vacuum at idle.
You will need ISTA+ to get to the bottom this. Could be a sensor $$$ , could be the shaft and bearings, could be the DME etc.
The valvetronic system is not one to randomly toss parts at!
My ISTA has a few test plans. Not sure if ISTA+ does?

If you are going to replace the sensor, at least make sure it's OEM at the very least.

 

[MrMCar]

Is there an egregious amount of carbon buildup on the intake valves???

 

[hereforbeer]

Is there an egregious amount of carbon buildup on the intake valves???

Hey,
It crossed my mind that there might be an restriction somewhere, because when i replaced the (really filthy) air filter, my car's idle/acceleration improved it by a ton. So I will definitely have to look into this!

 

[hereforbeer]

here's a picture of my lambda values.. don't know too much about interpreting them so any input is appreciated!
All I know is that I noticed is after changing my air filter the Lambdasensor Add. Bank 1 went from -4.5 to -1.78 and has been stable there ever since.

 

[hereforbeer]

Intake was clean; Didn't find any visible leaks either. What next?

 

[MrMCar]

Are there any faults present?
What are the current valvetronic settings?

Is there a "Engine Oil Disturbed" button somewhere in the test plans?
This can delete adaptations after repairs. Hidden by BMW.
I generally don't like resetting adaptations for proof of concept reasons, but for valvetronic it's needed sometimes.

 

[hereforbeer]

Are there any faults present?
What are the current valvetronic settings?

Is there a "Engine Oil Disturbed" button somewhere in the test plans?
This can delete adaptations after repairs. Hidden by BMW.
I generally don't like resetting adaptations for proof of concept reasons, but for valvetronic it's needed sometimes.

Haven't had any fault codes yet. What do you mean by the valvetronic settings? I'll see what I can find in the test plans section.

 

[hereforbeer]

update: the problems disappear after disconnecting the eccentric shaft sensor plug. Learned new valvetronic values by ISTA; No difference.
Ran the intermediate lever wear check; all cylinders results in 0, except for cylinder #3 gives 10.

On a cold morning start, I had a CEL pop up for a moment and gave me cyl #3 misfire and intake camshaft sensor error, haven't returned tho.
Valvetronic issue? where should I start?