VW Polo Cold Start Fix: Key Warning Signs & Solutions

Had the exact same symptoms on a 2004 VW Golf TDI. The hard starting and rough idle turned out to be failing fuel injectors. Initial diagnosis showed poor fuel delivery and inconsistent spray patterns across multiple injectors. The engine would struggle most during cold starts, and the rough idle would persist until the engine reached operating temperature. Engine misfire was particularly noticeable at low RPMs. After proper diagnosis with specialized testing equipment, two injectors were found defective and needed replacement. This is a serious issue that requires immediate attention, as faulty injectors can lead to increased fuel consumption, drop in power, and potential engine damage. The fuel system repair involved removing and testing all injectors, replacing the defective ones, and performing a complete system reset with computer diagnostics. The symptoms disappeared completely after repair, and the engine returned to smooth operation with proper cold starting performance. Worth noting that aftermarket parts are available, but using OEM injectors is recommended for these engines to ensure proper fuel delivery and atomization. Would strongly recommend having a qualified diesel specialist perform proper diagnostics rather than just cleaning, as injector problems often require replacement rather than cleaning when these symptoms appear.

Thanks for sharing your experience with the Golf TDI injector issues. Your situation sounds very similar to what I faced with my Polo. I went ahead and had the fuel injection system checked after reading posts like yours. The injector test revealed two problematic injectors and the mechanic recommended a full fuel system service including new injectors. Would you mind sharing what the repair ended up costing you? Also curious if youve had any fuel delivery issues since the fix? Im trying to budget for this repair and want to make sure I address everything while its being worked on.

Really glad I could help with your decision to get it checked out. Since having the faulty cold start injector replaced, my Golf TDI has been running perfectly with no fuel delivery issues whatsoever. The rough idle and cold start problems completely disappeared after the repair. The total cost came to 515€ for replacing the defective injection valve. While not cheap, the improvement in performance and reliability made it worthwhile. The fuel rail pressure is now consistent, and the engine starts smoothly even on cold mornings. If your mechanic found two problematic injectors, definitely get them both replaced at the same time. Partial repairs of the fuel system often lead to ongoing issues. Modern diesel engines are particularly sensitive to fuel injection problems, so using quality parts is crucial for long-term reliability. Just make sure your mechanic performs a proper system reset and calibration after installing the new injectors. This ensures optimal fuel delivery and prevents any warning lights from persisting.

I took my Polo to a reputable diesel specialist last week based on the advice here. The diagnostic testing confirmed two failing injectors causing my hard starting and rough idle problems. Total repair came to 980€ including parts and labor for replacing both injectors, plus a full fuel system cleaning service. The difference in performance is remarkable. No more cold start problems or rough running, the engine fires up immediately and runs smoothly from the first turn of the key. The specialist also checked the fuel rail pressure and performed a complete system calibration after installing the new OEM injectors. While the cost was significant, the peace of mind knowing the fuel injection system is working properly makes it worthwhile. The mechanic explained that catching failing injectors early likely prevented more extensive engine damage. Going to a qualified shop that specializes in diesel injection systems was definitely the right call.