VW Beetle TDI: Power Loss and Rich Fuel Mix Issues

Had the exact same symptoms on my 2012 VW Golf TDI last season. The rich mixture and power loss pointed to a faulty fuel injector. The engine computer was compensating by adjusting the fuel delivery, leading to poor fuel economy and that jerking sensation. Running tests confirmed one injector was stuck partially open, causing uneven fuel spray pattern. This explains the rough running and check engine light. Its a common issue that requires replacing the defective injector. The catalytic converter and intake manifold needed inspection too since excess fuel can damage these components over time. The repair involved: Diagnostic testing to identify the problematic injector, Removing and replacing the faulty injector, Cleaning the intake system, Reprogramming the engine computer, Test driving to verify proper fuel delivery This is considered a serious repair since bad injectors can lead to engine damage if left unfixed. The symptoms match your case exactly, reduced power, jerking, and increased fuel consumption. Getting it fixed soon is important before it affects other engine components. Would suggest having a complete fuel system diagnostic done rather than just accepting the rich mixture assessment without testing. Bad spark plugs or sensor issues can show similar symptoms but are less likely on a diesel.

Thanks for describing what happened with your Golf. Sounds very close to what I am experiencing with my Beetle right now. The fuel injector replacement makes sense given the symptoms. The check engine light and performance issues started getting worse over the past couple weeks, especially the jerking during acceleration. Since your repair included work on both the intake manifold and injectors, would you mind sharing what the total cost ended up being? Also curious if youve had any other issues pop up since getting it fixed? The engine computer reprogramming part makes me a bit nervous about potential complications down the road. Currently debating between two repair shops and want to get a sense of reasonable pricing before committing to one. Really helpful to hear from someone who went through a similar repair successfully.

I ended up paying 515€ total for the repair, which focused mainly on replacing the faulty injector. The good news is that after 8 months, the engine runs perfectly with no rich mixture issues or other problems. The fuel economy returned to normal levels and the jerking completely disappeared. The mechanic found that only one injector was defective, so there was no need for extensive intake manifold work, just a basic inspection and cleaning. The engine computer reprogramming was straightforward and hasnt caused any complications. The catalytic converter was also checked but showed no damage from the rich fuel condition. Would suggest getting quotes specifically for injector replacement and diagnostic testing. Some shops might recommend unnecessary additional work. The main thing is fixing that faulty injector before it causes more serious engine problems. Since getting it repaired, the engine runs smoothly and fuel consumption is back to factory specs.

I took my Beetle to a trusted diesel specialist yesterday after reading the feedback here. The diagnostic confirmed a faulty injector, exactly as described. The air filter was also quite dirty which contributed to the rich mixture problem. The total repair came to 495€ including: New fuel injector, Air filter replacement, Computer reset, Labor costs The mechanic showed me the old injector which was clearly damaged. They completed the work in about 4 hours. Already notice smoother acceleration and better fuel economy on the drive home. The check engine light is now off and no more jerking or rough running. Really glad I got a second opinion before going back to the original shop that just gave a vague rich mixture diagnosis without proper testing. Having the injector replaced early likely prevented damage to other engine components. Will monitor the fuel consumption over the next few weeks but so far the engine feels like new again.