Rough-Running VW Tiguan Diesel Points to Injector Issues

Had similar issues with my 2016 VW Passat diesel. The symptoms match what I experienced, rough idle, jerking during acceleration, and check engine warnings. The root cause was a combination of failing fuel injectors and a cracked exhaust manifold. The exhaust leak was causing incorrect readings in the oxygen sensors, which made the engine run rich and created the rough running conditions. The bad fuel injectors were not helping either, contributing to the uneven idle. This turned out to be a serious repair that required replacing multiple fuel injectors and the exhaust manifold section. The timing belt was also inspected during this work since the components were accessible. For your Tiguan symptoms, I would suggest: Getting the fuel injectors tested and cleaned, Having the exhaust system thoroughly checked for leaks, Checking the ignition coils as they can cause similar symptoms, Verifying the air filter is clean and properly seated Exhaust leaks often start small but can quickly develop into larger issues affecting engine performance and emissions systems. Best to address these symptoms promptly before additional components get affected.

Thanks for sharing your experience. I had nearly identical symptoms with my Tiguan last winter. The engine misfire and jerking turned out to be failing spark plugs and a faulty crankshaft sensor causing the erratic behavior. Did you end up getting it all fixed with that repair, and would you mind sharing what the total cost was? Also wondering if you have noticed any other issues since the work was completed. Sometimes these problems can be related to other failing components that show up later.

Good news, after replacing the faulty fuel injectors and fixing the exhaust leak, my Passat has been running perfectly smooth. No more engine misfire or uneven running issues. The repair cost was 265€ for the exhaust system work, which resolved the rough idle completely. The mechanic did a thorough inspection while fixing the exhaust and confirmed no other components needed attention. The timing belt and ignition coils were all in good condition. Its been about 8 months since the repair and no related problems have surfaced. Your situation with the crankshaft sensor and spark plugs shows how similar symptoms can have different root causes. Getting an accurate diagnosis is crucial since engine running issues can stem from multiple components. Glad you got yours sorted out as well.

Thanks everyone for the detailed replies. I finally got the issue resolved last week. Took it to a different mechanic who actually took the time to properly diagnose the problem. The rough idle and jerking turned out to be caused by two failing fuel injectors and a clogged air filter. The total repair came to 890€ including parts and labor. The mechanic showed me the old injectors which were heavily carboned up. After the repair, the engine runs perfectly smooth again. No more jerking during acceleration and the rough idle is completely gone. The check engine light cleared up right after the work was done. The new mechanic also did a full inspection and found everything else to be in good working order. The ignition coils and other components checked out fine. Really glad I got a second opinion instead of throwing parts at the problem like the first shop suggested.