VW Golf TDI Rough Running + Poor MPG Fix Guide

Had a similar issue with my 2010 VW Jetta TDI. The symptoms matched exactly, rough running, poor fuel economy, and the check engine light warning. The main problem was a faulty fuel injector creating a rich mixture condition. A specialized diagnostic scan revealed the injector was not atomizing fuel properly, leading to incomplete combustion. The oxygen sensor readings confirmed the air-fuel ratio was way off. The repair required replacing two fuel injectors and cleaning the remaining ones. This is considered a serious issue since bad injectors can: Cause engine damage if left unchecked, Lead to excessive smoke, Result in failed emissions tests, Create carbon buildup The repair process involved: 1. Full computer diagnostic scan 2. Fuel injector flow testing 3. Removal and replacement of faulty injectors 4. Reprogramming the engine control unit 5. Road testing to verify fix Important to have this diagnosed by a shop with experience in VW TDI systems. The check engine light and performance issues should not be ignored as they typically worsen over time.

Thanks for sharing your experience with the Jetta injector problems. This sounds exactly like what I am dealing with on my Golf, the rich mixture symptoms and check engine warning match up perfectly. My regular mechanic kept replacing spark plugs thinking that would fix it. How much did the full injector replacement end up costing you? And has everything been running smoothly since the repair or did you have any other issues pop up? I want to make sure I budget properly before heading to a VW specialist.

The repair definitely resolved the rich fuel mixture issues in my Jetta. The oxygen sensor readings returned to normal and the engine runs perfectly smooth now, especially during acceleration. The catalytic converter was thankfully not damaged from the rich condition. The total cost breakdown for my repair was 515€, which included: Complete fuel injector replacement, Labor for testing and installation, ECU reprogramming after the fix Since having the faulty injectors replaced, the car has been running flawlessly for over 8 months. Fuel economy is back to normal and the check engine light has stayed off. Just make sure you find a shop that specializes in VW fuel injection systems, your regular mechanic changing spark plugs definitely would not fix this type of problem. The diagnostic readings showed the air-fuel ratio was way off before the repair, but now everything is properly balanced. Well worth the investment to prevent more serious engine damage down the line.

I decided to take my Golf to a specialized VW diesel shop after reading about your experience. You were right, it was definitely the fuel injectors causing the rich mixture problem. Found a great mechanic who properly diagnosed it instead of just throwing parts at it like my regular shop did. The total repair came to 490€ which included: New fuel injectors, Diagnostic testing, Cleaning the intake manifold, Programming the new injectors Had it done last week and the difference is incredible. Engine runs smooth again, no more rough acceleration, and the check engine light is finally off. Fuel economy has improved dramatically too. The mechanic showed me the old injectors and they were pretty badly worn. Really glad I asked here first instead of wasting more money on unnecessary spark plug changes. Having a knowledgeable diesel specialist handle it was definitely the right call. Thanks again for pointing me in the right direction with the fuel injection system diagnosis.