Rough Diesel Engine Points to EGR Valve Failure

I had very similar issues with my 1998 Baleno diesel last year, having some experience working on diesel engines. The symptoms you describe match almost exactly what I encountered, rough idle, excessive smoke, and that characteristic hissing during acceleration. The EGR valve was indeed the culprit, causing poor recirculation of exhaust gases. Initially, I thought cleaning might solve it, but the valve was completely jammed. The workshop confirmed this after running diagnostics. The full repair, including parts and labor, cost 355€. The repair completely resolved the power loss and rough running. Fuel consumption returned to normal, and the engine ran smoothly again. Most importantly, it passed the emissions test without issues afterward. Before jumping to conclusions though, could you share: Current mileage on your vehicle, How long these symptoms have been present, Any recent maintenance history, Whether the check engine code has been read These details would help confirm if your situation matches what I experienced. The workshop mentioned these symptoms could sometimes also indicate issues with the intake manifold or fuel system in these models.

Just had my 118362 KM service last month, and your symptoms sound identical to what I experienced. The rough idle and smoke were exactly what led me to discover my EGR valve problems. My mechanic found a vacuum leak near the EGR valve that was causing similar issues. The diagnostic scan revealed multiple codes related to exhaust flow. When they cleaned and tested the EGR valve, it was completely clogged with carbon deposits. The total repair came to 280€, which included cleaning the entire EGR system and replacing some worn vacuum lines. After the fix, the check engine light cleared, and the diesel engine returned to running smoothly with normal fuel consumption. If your symptoms persist, have them check the intake manifold gaskets too, they can cause similar issues when failing.

Thanks for the follow-up about your repair experience. Your situation really mirrors what I went through with my Baleno diesel. The vacuum leak discovery is particularly interesting since I had overlooked that possibility initially. Good point about the intake manifold gaskets. After my EGR valve replacement, the workshop actually found minor leaks there too, which they fixed during the service. In these older diesel models, the entire exhaust gas recirculation system tends to develop issues around this mileage range. Your repair cost of 280€ seems reasonable compared to the 355€ I paid, especially considering they did a thorough cleaning of the system. The preventive replacement of vacuum lines was smart, this often prevents future rough idle issues from developing. Since the automotive repair resolved your problems completely, it confirms my experience that thorough diagnostics and proper repairs are crucial for these emissions-related issues. My vehicle emissions have remained stable since the fix, with no return of the check engine light or performance problems. Next time you service the car, consider having them check the EGR cooler too. In my case, it showed early signs of clogging about 6 months after the initial repair.

Thank you for sharing those details about the repair costs and vacuum line replacement. The EGR valve problem on my Baleno diesel turned out to be more complex than initially thought. After noticing the rough idle getting worse, I took it to the shop today. The diagnostic scan showed error codes P0401 and P0402, confirming insufficient EGR flow. The mechanic found both the valve and associated vacuum lines were deteriorated. The cleaning and vacuum line replacement cost came to 295€. The automotive repair work revealed carbon buildup was indeed restricting exhaust gas flow. My diesel engine now runs much smoother with no more jerking or hissing during acceleration. Most importantly, the shop tested the emissions and confirmed everything is within spec for the upcoming test. For others who might face similar symptoms, get the full EGR system checked, not just the valve. In my case, addressing the vacuum leaks was crucial for resolving the rough idle completely. The fuel consumption has already improved noticeably after just a few drives.