VW Nivus Rough Idle & Jerking: Common Fixes Guide

I had a similar issue with my 2018 VW T-Roc, and being someone with basic car maintenance experience, I first thought it was related to the fuel system. The symptoms matched exactly what you describe, rough idle, jerking during acceleration, and the engine running unevenly. Initially suspected the fuel pump or crankshaft sensor, but after taking it to a workshop, they diagnosed a significant exhaust leak near the manifold. The leak was causing incorrect readings in the oxygen sensors, which made the engine run rich at times, leading to the rough idle and performance issues. The total repair came to 265€, including parts and labor. Before jumping to conclusions, it would help to know: How many kilometers/miles are on your Nivus? Did you notice any unusual exhaust sounds or smells? Does the problem get worse when the engine is cold or warm? What error code is stored in your ECU? An exhaust leak can sometimes mimic engine misfire symptoms, so its worth checking the entire exhaust system before replacing more expensive components like fuel injectors. Would definitely recommend getting it properly diagnosed, as driving with an exhaust leak can lead to more serious issues over time.

Had my last service at 145000km. I changed fuel type recently and noticed the issue started shortly after. Earlier I used the normal 95 octane fuel, but switched to premium 98 octane thinking it would be better for the engine. The rough idle seems more noticeable in the morning when the engine is cold. The stored error code reads P0171, System Too Lean Bank 1. After reading your experience with the oxygen sensor, I checked and noticed a slight ticking sound from the exhaust area, though not sure if related. The check engine light stays on constantly now. Based on your feedback about the exhaust leak possibility, I will have the workshop check the manifold area during diagnosis. Thanks for pointing out the potential connection between exhaust leaks and oxygen sensor readings.

Thanks for providing those additional details about your Nivus, it really helps narrow things down. When my T-Roc had similar symptoms, I also noticed they were worse during cold starts. The P0171 code combined with that ticking sound strongly suggests an air leak, just like what I experienced. In my case, the exhaust leak caused the oxygen sensors to detect a lean condition, making the ECU compensate by adding more fuel. This created the rough idle and jerking. The fuel grade change might be coincidental timing, as premium fuel typically wouldnt cause these symptoms. My ignition coils were also tested during diagnosis since they can cause similar issues, but the real culprit was definitely the exhaust leak. A quick suggestion before the workshop visit: check your air filter condition. A clogged air filter can contribute to lean conditions, though its likely not the main issue given the ticking sound youre describing. For reference, after my repair: The rough idle completely disappeared, No more jerking during acceleration, Check engine light went off and stayed off, Engine ran smoothly regardless of temperature It sounds like youre dealing with something very similar to what I experienced. Getting it checked soon is smart, these issues tend to worsen if left unaddressed.

Thank you for everyone's input. After having the car diagnosed at the workshop today, it turns out there was indeed an exhaust leak at the manifold, along with a failing oxygen sensor. Both issues were causing the lean condition and rough idle symptoms. The total repair cost was 380€, which included: Replacing the exhaust manifold gasket, New oxygen sensor, Labor costs They also inspected the ignition coils and air filter while doing the work, but these components were fine. The fuel pump and injectors were tested and showed normal operation. The car now runs perfectly smooth, no more rough idle or jerking during acceleration. The check engine light is off and the engine performance is back to normal. Glad I had it checked before the problem got worse. The workshop mentioned these issues are somewhat common on these engines after 140000km, especially if there has been any previous work done around the manifold area. Thanks again for helping me identify the likely cause before the workshop visit. It definitely helped knowing what to have them check first.