Rough Idling A6 TDI Needs Knock Sensor Fix

Recently dealt with similar symptoms in my Audi A4 2.0 TDI 2014. The malfunction indicator light was indeed triggered by knock sensor issues, combined with a deteriorated wiring harness connection. The auto repair involved checking the entire knock sensor assembly. In my case, the root cause was a damaged wire connector and corrosion buildup at the sensor mounting point. The harness had worn through due to engine vibration, causing intermittent signal issues. This explained both the rough idle and increased fuel consumption, as the engine management system was receiving incorrect detonation data. The fix required replacing the knock sensor unit and associated wiring harness. While not a major engine repair, it needed specialized diagnostic equipment to properly calibrate the new sensor. The warning light issues completely resolved after repair, and fuel consumption returned to normal. For Audi TDI engines, this is a relatively common car problem that can worsen if left unaddressed. Would suggest finding a shop with Audi diagnostic capabilities, as generic scanners might not pick up all sensor-related issues.

Thanks for sharing those details about the knock sensor repair. My situation sounds quite similar, currently waiting for the parts to arrive at my shop. Mind sharing what the total repair cost came to for you? Just wondering if prices have changed much since then. Also curious if youve had any ignition timing issues or other problems pop up since getting it fixed? My fuel efficiency is still terrible and Id like to avoid any surprises down the road.

Since getting my Audi fixed, the knock sensor repair has held up perfectly. The repair cost came to 95 Euro, which covered fixing the faulty cable connection, much simpler than expected once they diagnosed it correctly. The warning light hasnt returned and the engine knock issues completely disappeared. The fuel consumption returned to normal immediately after the repair. No ignition timing problems or other issues have surfaced in the months since. The rough idling that was plaguing the car is completely gone. Looking back, the malfunction indicator was spot on, it really was just the knock sensor causing all those symptoms. The total repair ended up being much more affordable than initially feared, since they only needed to fix the connection rather than replace the entire unit. From what I understand, prices for this type of repair have stayed fairly stable. Best thing was finding a shop that properly diagnosed the problem the first time around. A failing knock sensor can cause multiple car problems, but once fixed properly, it shouldnt give you any more trouble.

Thanks for the input. I finally got my Audi fixed last week and wanted to share my experience. After searching around, I found a certified shop specializing in European cars. The mechanic immediately spotted the poor performance issues and ran a full diagnostic. Turns out my car problems were indeed related to the knock sensor, but there was also a clogged fuel injector contributing to the rough idling. The total repair came to 280 Euro, higher than expected but they did a thorough job. The check engine light is now off and the car runs smoothly again. The fuel consumption has significantly improved, back to normal levels. The engine knock is completely gone and the idle is perfect. Really glad I decided to get it properly diagnosed instead of continuing with the previous mechanic who kept missing these issues. For anyone facing similar warning light problems with their Audi, its worth paying a bit more for a shop that really knows these engines. The expertise made all the difference in getting it fixed right the first time.