ProMaster Diesel Jerks While Accelerating, Fix Guide

As someone with a fair amount of repair experience, I dealt with very similar symptoms on my 2016 ProMaster diesel last year. The rough idle and jerking during acceleration turned out to be related to a leak in the exhaust system, which was affecting the oxygen sensor readings and causing irregular fuel delivery through the fuel injectors. Initially thought it might be the crankshaft sensor or ignition coil, but the workshop diagnosed a significant exhaust leak near the manifold. This was causing false readings and throwing off the entire fuel management system. The repair involved replacing some gaskets and a small section of exhaust piping, totaling 265€ including labor. The fix took about 4 hours and completely resolved the jerking and rough idle issues. The engine light also cleared up after the repair. To better assist with your specific case, could you share: Current mileage on your vehicle, Whether you notice any exhaust smell in the cabin, If the problem gets worse when the engine is cold or warm, Any unusual exhaust noise or smoke, When the symptoms first appeared This information would help determine if your issue matches what I experienced or if it might be something different.

Had my last service at 126629 KM and can confirm these exact symptoms appeared right after. Mine also started with jerking during acceleration, but the real culprit turned out to be faulty fuel injectors combined with a failing oxygen sensor. The repair showed significant carbon buildup was preventing proper fuel atomization. Got it sorted by replacing 2 fuel injectors and the oxygen sensor, fixing the engine misfire completely. The total repair came to 890€ including parts and labor. Worth checking the spark plugs too while theyre at it, mine were pretty worn but still functional. The whole job took about 6 hours at the shop. Running smooth now with no engine light or performance issues.

Thanks for the update on your ProMaster repair. Interesting that your fuel injectors were the root cause, my exhaust leak caused similar symptoms but was a much simpler fix. The oxygen sensor failing seems to be a common issue on these models, especially around the 120-130K mark. The carbon buildup you mentioned is definitely something other owners should watch for. Since fixing mine, I've switched to premium diesel and noticed much cleaner running. The rough idle completely disappeared after my repair, just like yours. Makes sense they checked the spark plugs during the service. Even though my issue was exhaust-related, the ignition coil and spark plugs can show similar symptoms when failing. Your repair cost was higher than mine, but replacing injectors is always more expensive than exhaust work. The air filter should also be checked regularly on these engines, a clogged one can contribute to carbon buildup and poor performance. Since both our fixes, have you noticed better fuel economy? Mine improved quite a bit after getting the exhaust sorted.

Based on everything that was discussed, I can definitely say I made the right call getting this fixed promptly. The fuel injectors and oxygen sensor replacement completely resolved my acceleration issues. While 890€ felt steep initially, the improvement in performance and elimination of that worrying jerking motion proved it was money well spent. The carbon buildup issue they found makes sense given the mileage. Appreciate everyone sharing their experiences, helps confirm this seems to be a common wear point for these engines. The shop mentioned regular fuel system cleaning could help prevent future issues, so will likely add that to my maintenance schedule. Running much smoother now and fuel economy has improved noticeably. Really glad I got the spark plugs checked while they were working on it, even though they werent the main problem. The whole repair process took longer than expected at 6 hours, but the end result was worth the wait. No more check engine light and the engine feels like new during acceleration. Will definitely keep an eye on the crankshaft sensor and ignition coil going forward, since these components can show similar symptoms when starting to fail. Thanks for all the helpful input on troubleshooting these issues.