Q5 Hybrid Rough Idle & Knock Sensor Warning Light Fix

Having experienced similar symptoms with my 2015 Audi Q7 Hybrid, I can relate to this engine knock concern. The malfunction indicator and rough idle often point to sensor connectivity issues rather than a complete knock sensor failure. When my car developed these symptoms, the initial diagnosis revealed loose wiring connections to the knock sensor. The check engine light was triggered by intermittent sensor signals. The rough running condition and poor fuel economy were direct results of the engine computer receiving incorrect knock sensor data, causing it to run in a conservative safety mode. The actual repair involved: Testing the knock sensor circuit, Repairing corroded wiring connectors, Securing loose plug connections, Clearing the malfunction indicator codes, Performing a system reset This was not a serious mechanical issue, but leaving it unaddressed could lead to engine damage as the computer cant properly adjust timing. The repair required specialized diagnostic equipment to verify proper sensor operation after fixing the connections. Would suggest having a certified technician perform a complete diagnostic check, as similar symptoms can also indicate other sensor-related problems in the hybrid system.

Thanks for sharing your Q7 experience. I had a very similar situation on my Q5 last winter, rough running, warning lights, and terrible fuel economy. Turned out my car problems were also electrical, but it was the crankshaft position sensor causing the poor performance rather than knock sensor wiring. Would you mind sharing what the repair cost came out to? And has everything been running smoothly since the fix? After my auto repair, I had to go back once more because the check engine light returned, though it was covered under the initial work warranty.

Thanks for asking about the follow-up. Since getting the knock sensor connection fixed, my car has been running perfectly with no check engine lights or auto repair issues. The fuel efficiency is back to normal, and the rough running problems are completely resolved. The total repair cost was 95 Euro for fixing the faulty cable connection to the knock sensor. This was much less expensive than I initially feared, as poor performance issues can sometimes lead to costly repairs. The ignition timing is now working correctly since the sensor is receiving proper signals. The key was catching it early before it could cause any engine damage. Unlike your experience with the crankshaft sensor, I havent needed to return for any additional fixes. The original repair has held up well with no recurring car problems or warning lights. If your check engine light comes back on, definitely have them check all sensor connections thoroughly. Sometimes these electrical issues can be tricky to diagnose on the first try.

Thanks everyone for the helpful feedback. Just wanted to share how my situation turned out. Finally took my Q5 to a different auto repair shop last week. The mechanic found multiple issues causing the poor performance, not just the knock sensor the first place mentioned. Turned out the main culprit was a failing fuel injector along with some loose wiring connections. The check engine light was actually trying to warn about both problems. Total repair came to 450 Euro including parts and labor. After the fix, the rough idle is completely gone and fuel efficiency has improved significantly. No more malfunction indicator lights either. Definitely learned my lesson about getting a second opinion when dealing with complex engine issues. The proper diagnostic testing made all the difference in identifying the real problems. Really glad I asked for advice here before proceeding with the original repair quote. While it ended up costing more than just a knock sensor replacement, at least all the issues got properly fixed the first time at this shop.