VW Polo Diesel Misfire: Rough Running + Power Loss Fix

Had a similar issue with my VW Golf TDI 1999 last season. The rough idle and power loss symptoms match exactly what I experienced, particularly during acceleration. The check engine light came on after about a week of these symptoms. The diagnosis confirmed a faulty fuel injector in cylinder 2, which was causing severe combustion misfire. This is actually a common issue with diesel engines of this age. Its not just about the injector itself, the entire fuel delivery system needed inspection. In my case, carbon buildup was blocking the injector nozzle, preventing proper fuel atomization. This created irregular combustion patterns, explaining the rough running and power loss. The repair involved: Complete fuel injector removal and testing, Professional cleaning of all injectors, Replacement of one defective injector, Fuel system cleaning, ECU reset to clear fault codes This was definitely a serious repair that required specialized diagnostic equipment and expertise. Attempting DIY fixes could potentially cause more damage. Would strongly recommend finding a diesel specialist rather than a general mechanic, as injector work requires specific knowledge and tools. While spark plugs might be your first thought, remember that diesel engines dont use them, they use glow plugs for starting, but thats not related to your current symptoms.

Thanks for sharing your experience. This lines up exactly with what my Polo was doing. I also had rough idle and engine misfiring that got worse over time. Question, do you remember roughly what you paid for the full repair? And has everything been running smoothly since the injector work was done? I want to budget properly and make sure this fix will actually solve the issue long-term.

After that injector repair on my Golf TDI, all combustion misfires detected by the ECU were completely resolved. The rough idle disappeared, and throttle response returned to normal, feels like a different car now. The total bill came to 515€, which covered the new injector, system cleaning, and labor. While it might seem steep, the specialized work on diesel injection systems requires proper diagnostic equipment and expertise. The engine has been running perfectly for months now, no check engine lights, no power issues, and fuel economy is back to normal. These diesel injector issues are pretty common in our generation of VWs, but once properly fixed, they tend to stay fixed. The key was having a diesel specialist handle it rather than a general mechanic. The proper diagnosis and repair may cost more upfront, but it prevents repeated issues or incomplete fixes that could end up costing more in the long run.

I decided to get my Polo fixed after getting good advice here. Found a diesel specialist who actually charged less than my previous mechanic, 480€ total for fixing the fuel injector problems. The repair took about 5 hours. They confirmed it was a faulty injector causing the cylinder misfire and rough idle problems. They cleaned the entire fuel system, replaced one bad injector, and reset the computer. Huge difference in how the car runs now. The throttle response is crisp again, no more check engine light, and the engine runs smoothly. Really glad I went with a specialist shop instead of trying quick fixes or using my old mechanic. For anyone with similar issues, definitely worth spending a bit more for proper diagnosis and repair by someone who knows diesel systems. The car feels like new again and I expect this fix to last.