PDA

View Full Version : Excessive Ignition Knock Control values at clutch engagement and low rpm - HELP



Believer
10-20-2016, 07:24 AM
Hello all - I am seeking assistance from the 1.8t gurus of these forums in an attempt to try and figure out what is going on with my car. I hate posting 'help me' threads but I am really at a dead end here with trying to resolve this.

Some relevant facts before jumping in:
-New Bosch F6DTC plugs
-Relatively new 034 PCV components
-New VVT tensioner with chain
-Mechanical timing verified
-Vacuum and boost leak free

So the issue that is occurring is that when the clutch is engaged and throttle blipped to move the vehicle, the ECU is pulling out between 1.5* and 7* of timing across all cylinders and continues to pull timing through 3k rpm. This almost always happens pulling away in first gear and usually continues to happen after shifting into 2nd unless I wind first out enough for the timing pull to stop before shifting into 2nd. The effect of this timing pull can definitely be felt by how slow the car will accelerate in the low RPM and especially if on a hill of any sort.

I have observed that resetting the trims and adaptations causes the issue to stop for a time, but after 100 miles of driving or so and the vehicle getting up to temperature, the issue always resurfaces. Ambient temperatures seem to have a small effect on how much timing the ECU pulls out.

I've posted 2 links to data logs capturing this issue as it happens. I would greatly appreciate anyones thoughts, theories, troubleshooting steps to perform, really anything anyone has to offer.

https://drive.google.com/open?id=0B6bElYB_T9BFNllxN0QxWmpwY2c

Cell 3814 is the most excessive example i was able to capture in the above log. Ambient temperature in this log was between 81* - 84* F.

https://drive.google.com/open?id=0B6bElYB_T9BFRVQwczV6dHdqdUE

MetalMan
10-20-2016, 07:57 AM
This is sort of random, but I'm curious to know if your clutch switch is working properly. It can be checked with VCDS.

How old are your knock sensors? Crank sensor? Cam sensor? Have you verified cam timing/phasing?

Believer
10-20-2016, 08:12 AM
This is sort of random, but I'm curious to know if your clutch switch is working properly. It can be checked with VCDS.

How old are your knock sensors? Crank sensor? Cam sensor? Have you verified cam timing/phasing?

I will verify the clutch switch functionality in VCDS, just need to get the cable back from my brother.

Knock sensors, crank sensor and cam sensors are all original, so 250K+ miles on them. No DTCs whatsoever for anything timing related.

Edit: the crank sensor is not original. That was replaced about 20k miles ago when I built the motor.

By verifying cam timing/phase do you mean watching the solenoid switch for the VVT?

Believer
10-21-2016, 07:53 AM
I just want to add to this that the issue is noticeably less when the temperatures are cooler outside. I've noticed a trend over the past few days where the mornings have been cool and the afternoons quite warm.

Believer
12-22-2016, 01:54 PM
Bumping this thread up because the issue persists.

Since my last post I verified the clutch switch is working in vcds, have replaced both knock sensors. I guess my next step is to try a different cam sensor.

Just to reiterate the issue in short: taking off from a stop, the moment the clutch is slipped and throttle blipped and the car starts rolling, massive timing pull occurs. If i let off the throttle immediately after the clutch is engaged, then get back into the throttle I can make the corrections go away. But if I stay in the throttle following clutch engagement, the timing pull persists. Today is logged 12* being pulled out across multiple cylinders. It was 50* f outside. I'm just completely stumped and the way this effects driveability is painful.

Sent from my LG-H810 using Tapatalk

MrSnickelsnizer
12-24-2016, 10:48 AM
oem tensioner or not.

Believer
12-24-2016, 11:49 AM
oem tensioner or not.
Cam chain tensioner? I purchased this one from FCP. https://www.fcpeuro.com/products/audi-vw-engine-timing-chain-tensioner-058109088e

I still have my old one but it was suspect. I could swap the solenoid over to test but am not confident in the rest of the original one @ 250k

Sent from my LG-H810 using Tapatalk