VW Sharan Diesel Cold Start Struggles and Rough Idling

As a VW Touran 2.0 TDI (2008) owner, I faced nearly identical symptoms. The hard starting and rough idle turned out to be faulty fuel injectors, which were causing incomplete fuel atomization during cold starts. The diagnosis revealed carbon buildup inside the injectors, restricting proper fuel injection and creating inconsistent spray patterns. This caused the engine management system to compensate by adjusting the fuel rail pressure, leading to the rough idle symptoms. The repair required professional injector cleaning service, which helped but didnt fully resolve the issue. Eventually, two injectors needed replacement as they were beyond salvaging. The fuel injection system is critical for diesel engines, especially during cold starts, and neglecting these symptoms can lead to more severe engine damage. Before going to a shop, have them check: Injector spray patterns, Fuel rail pressure, Return flow rates, Glow plug operation These starting issues and rough idle symptoms are common in VW diesel engines of this era, particularly when temperatures drop. Getting a proper diagnosis from a shop with diesel-specific diagnostic equipment is essential.

Thank you for sharing your experience with the fuel injection issues. My Sharan is now running much better after following your advice. The shop found similar problems with carbon deposits affecting the cold start performance. Would you mind sharing how much the injector cleaning and replacement cost in your case? Also curious if youve encountered any other fuel system problems since the repair? Learning about long-term outcomes would help me plan for potential future maintenance.

I had the complete job done last month, and the results have been excellent. The engine misfire and hard starting issues disappeared completely after replacing the faulty cold start injector. The total cost came to 515€, which included the new injector and labor. The fuel injection system has been working flawlessly since the repair. The morning starts are now smooth, with no rough idle issues. The shop performed a thorough injector test on all units, confirming that the other injectors were still functioning within specs, just needed cleaning. A key learning from this experience is that regular fuel system maintenance helps prevent carbon buildup in the fuel rail and injectors. Since the repair, I make sure to use quality diesel fuel and add fuel system cleaner every few thousand kilometers. No other fuel-related problems have surfaced in the past month. The investment was worth it considering how critical proper fuel delivery is for diesel engine performance, especially during cold starts.

Thanks for the feedback on the repairs. After dealing with those frustrating cold start problems, I finally got my Sharan sorted out properly. Went to a diesel specialist shop that actually knew what they were doing, unlike my previous mechanic. The diagnosis showed worn injectors and carbon buildup were causing my fuel delivery issues. Total bill came to 480€ for cleaning and replacing one bad injector. Money well spent, the rough idle and hard starting are completely gone now. Engine fires up instantly even on cold mornings. The shop also showed me the carbon deposits they cleaned out of the fuel system. Pretty eye-opening to see all that buildup. Now I'm religious about using good quality diesel and fuel system cleaner as preventive maintenance. It's been about 3 weeks since the repair and everything is working perfectly. No more engine misfire issues or rough running. Wish I'd gotten it diagnosed properly months ago instead of letting that first mechanic waste my time and money.