VW Passat Diesel Power Loss & Jerky Acceleration Fix

I experienced similar symptoms with my 2010 VW Jetta TDI. The jerking during acceleration and power loss turned out to be a faulty fuel injector. The mass air flow sensor readings were inconsistent, causing an incorrect air-fuel ratio that made the engine run lean. My injector had carbon buildup and was not atomizing fuel properly. The repair required removing and testing all injectors, with one showing complete failure. The mechanic found the injector was stuck partially open, leading to poor combustion and uneven fuel delivery. This is considered a serious issue since bad injectors can: Cause engine misfires, Damage the catalytic converter, Lead to increased fuel consumption, Create excessive exhaust emissions, Result in starting problems The diagnostic process involved checking fuel pressure, running injector pattern tests, and verifying the oxygen sensor readings. All injectors needed professional cleaning, plus replacement of the defective one. Given your symptoms and mileage, I recommend getting it checked soon. Continuing to drive with a failing injector risks more extensive engine damage.

Thanks for sharing that experience. I had nearly identical symptoms in my 2008 Passat when the mass air flow sensor failed, but it turned out my issue was also related to faulty injectors. The check engine light came on just like yours, and the car felt seriously underpowered. Do you remember roughly what the repair cost in your case? I ended up paying around 800€ for my fix, including parts and labor. Just wondering if thats in line with what you experienced. Also, has everything been running smoothly since the repair? My catalytic converter started acting up about 6 months later, but that might have been unrelated.

Thanks for asking about the costs. I was lucky, my total repair bill came to 515€, which covered diagnosing and replacing one problematic fuel injector. The mass air flow sensor readings are now stable, and the engine runs at the proper air-fuel ratio instead of too lean like before. Since fixing the faulty injector, my Jetta has been running perfectly for over a year. No more power loss, jerking, or check engine lights. The EGR valve and catalytic converter are both working as they should, I specifically asked the mechanic to check these components during the repair since they can be affected by poor fuel delivery. Your 800€ repair cost seems reasonable given they might have needed to replace multiple components. The fact your catalytic converter had issues later could be related, extended periods of lean running can definitely stress these parts. Quick tip: I now use high-quality diesel and fuel additives to help prevent carbon buildup in the injectors. This preventive approach costs a bit more but might save money long term.

After reading your response, I finally took my car to a trusted mechanic last week. The throttle body was actually clogged with carbon deposits, and two fuel injectors needed replacement. The check engine light was triggered by a failing oxygen sensor, which they also replaced. Total cost came to 650€, not as bad as I feared. The mechanic showed me the old parts and explained how carbon buildup caused the issues. The spark plugs looked pretty worn too, so I had those changed while they were at it. Been driving for a few days now and what a difference. No more jerking or power loss, and the engine runs smooth as silk. Really glad I didnt wait longer, could have caused more damage to other components. Thanks for the advice. Going to follow your tip about using better fuel and additives to prevent future problems. Lesson learned about not putting off repairs when these symptoms show up.