Vanos Rebuild Start Hesitation

[jamesfoley]

Bit of an update to this. Car is back with me now after just over two months. Long story short is the VANOS job I had done resulted in both intake valves on cylinder 5 to kiss the piston and bend enough for them not to close properly. Ended up needing the seats recut as the bent valve had damaged those. Also had new guides and a set of intake valves.

Car now starts on the button every time (so far), so its probably safe to say this has been sorted.

However, looking at data logs, I still have a lot of "Fuel System Status 8" data points.

https://datazap.me/u/jamesfoley/e46-...log=0&data=1-2

At this point I feel like maybe this is normal?

Honestly, looking at the status compared to RPM, it just looks like deceleration fuel cut, though why its 8 instead of 4 I do not know. Someone has commented that when I accelerate the car smells rich, but it runs and drives fine, and passes emissions so... 🤷

[sapote]

My bad I was mixed up, thinking you said one intake valve leaking.

[jamesfoley]

How can you tell from the leaking sound through the plenum that 1 or 2 intake valves leaking? they are both in the same port.

Not sure I understand what you mean. With air pressure into the cylinder and the crank rotated to compression stroke on cylinder 5, air was leaking through the intake.

Camera down into the cylinder shows both intake valve marks on the piston, so 1 or 2 valves are bent. Not terribly bent as the cylinder still held some pressure, but you could rotate past compression stroke by hand while filled with air, so it’s losing enough to be a problem.

Likely not the cause of my hard start as VANOS was still wrong, but I don’t want to risk dropping a valve and nuking the engine so just biting the bullet and having everything fixed.

[sapote]

1. "Both valves left an impression on the piston, but unsure if both are bent. I'd imagine if the piston kissed them both then they are equally unhappy, at least one of them is leaking air that you can hear through the plenum."
How can you tell from the leaking sound through the plenum that 1 or 2 intake valves leaking? they are both in the same port.
2. "VANOS was also found to be timed wrong again it seems, so the assumption is it was caused by timing at some point. Odd that its just a single cylinder though."
They could hit the piston hard and bent during manually turning the crank using a breaker bar, not during engine running.

With intake valve leaking, it should cause backfire in the intake, usually.

[jamesfoley]

Any idea what might have caused this? Both intake valves bent? Wrong VANOS timing could cause this when rotating the cranking during timing checking.

Both valves left an impression on the piston, but unsure if both are bent. I'd imagine if the piston kissed them both then they are equally unhappy, at least one of them is leaking air that you can hear through the plenum.

VANOS was also found to be timed wrong again it seems, so the assumption is it was caused by timing at some point. Odd that its just a single cylinder though.

Next step is head refresh and new valves. Car still ran and drove fine so pretty sure nothing else is technically wrong.

[sapote]

Small update, leak down test found bent intake valves on cylinder 5. ☹

Any idea what might have caused this? Both intake valves bent? Wrong VANOS timing could cause this when rotating the cranking during timing checking.

[jamesfoley]

Small update, leak down test found bent intake valves on cylinder 5. ☹

[Tomba]

would prefer tool32. Your US car right? If possible send a PM with your VIN

[jamesfoley]

Could be, if you read [aif_lesen] in Tool32, we could see which S/W is in and check which one is available.

I have these from DIS and the ECUWorx DME Utility to hand if they're of any use?

Software Ver: 211322001301-J424
Flashes remaining: 30

Programmed control module: 7833144
Basic control module: 7833145
Hardware number: 1B
Software number: 13
Diagnosis index: 30

Coding index: 00
Bus index: 60
Modification index: 01

Date: 03.11. 1
Supplier: SIEMENS


If not I'll pop out later and run the Tool32 job

[Tomba]

The DME flash counter is still at 30 which suggest it has never been touched since 2001? That's the only thing that feels kinda weird.

Could be, if you read [aif_lesen] in Tool32, we could see which S/W is in and check which one is available.

[jamesfoley]

Can't find anything unusual yet in the results shared.
Are we now tracking 2 problems 1. hard start and 2 fuel status 8? Or do these seem to be linked?

Like sapote, I would rather back up your DME data and check it. Eventually also flash it with latest software.

Yea thats correct.

1. Intermittent hard start regardless of how long the car has been sitting or engine temperature.
2. Fuel system status 8 appearing randomly when driving, though doesn't seem to affect performance. O2 sensors appear to drop to 0v when this occurs suggesting unburnt mixture?

The fuel status issue was discovered when capturing logs to figure out what might be causing the hard starts. Currently no evidence to suggest that they are related however.

Writing to the DME myself scares me a little, however if there was a way to safely dump the map from the DME to compare it with a known good map I could maybe try that.

The DME flash counter is still at 30 which suggest it has never been touched since 2001? That's the only thing that feels kinda weird.

[Tomba]

Can't find anything unusual yet in the results shared.
Are we now tracking 2 problems 1. hard start and 2 fuel status 8? Or do these seem to be linked?

Like sapote, I would rather back up your DME data and check it. Eventually also flash it with latest software.

[jamesfoley]

For normal engine, it should be status 4 and not 8:

1 Open loop due to insufficient engine temperature (Engine temperature is not used much these days to determine Closed Loop status, usually O2 sensor activity is used to determine when to switch to Closes Loop status)
2 Closed loop, using oxygen sensor feedback to determine fuel mix
4 Open loop due to engine load OR fuel cut due to deceleration
8 Open loop due to system failure
16 Closed loop, using at least one oxygen sensor but there is a fault in the feedback system

The STATUS_DIGITAL data only displays fuel cut as 1 for cut, 0 for no cut. The graph makes it look weird as it does some smoothing to show half values.

I'm not 100% sure how I'd get both the fuel status and the fuel cut data logging together though.

STAT_KL50_EIN is another odd looking one. Tool32 says this is Status Anlasser which is Starter state, not sure if this related to speed or something.

[sapote]

For normal engine, it should be status 4 and not 8:

1 Open loop due to insufficient engine temperature (Engine temperature is not used much these days to determine Closed Loop status, usually O2 sensor activity is used to determine when to switch to Closes Loop status)
2 Closed loop, using oxygen sensor feedback to determine fuel mix
4 Open loop due to engine load OR fuel cut due to deceleration
8 Open loop due to system failure
16 Closed loop, using at least one oxygen sensor but there is a fault in the feedback system

[jamesfoley]

Tomba Should be attached. Looks like this is the data that DIS uses for its status pages...