VW Eos Diesel Sluggish + High Fuel Use Points to Rings

Last month I dealt with similar symptoms on my 2009 VW Passat diesel. The fuel consumption increase and sluggish performance turned out to be failing fuel injectors, which had caused carbon buildup and affected cylinder pressure. The initial fuel injector problem led to incomplete combustion, which then damaged the piston rings. When the mechanic performed a compression test, it revealed significant pressure loss. The crankshaft turned out fine, but carbon deposits had accumulated in multiple cylinders. This became a serious repair as one problem had caused another. The engine knocking was the key indicator that multiple components needed attention. The repair required: Replacing all fuel injectors, Installing new piston rings, Thorough carbon cleaning, Computer system reset The car runs like new now, but catching these issues earlier could have prevented the cascade of problems. A compression test and fuel injector inspection should be your first diagnostic steps. The symptoms match exactly what I experienced, increased fuel consumption and sluggish performance typically point to fuel delivery or compression problems. Best to address this promptly before additional engine components get affected.

Thanks for sharing your experience. It sounds very similar to what Im going through. The sluggish performance and high fuel consumption match exactly. My turbocharger also feels less responsive lately, which adds to my concerns. Did you remember roughly how much the total repair cost? Just trying to get an idea for my budget. The fuel injector and piston ring replacement alone sounds expensive. Also curious if youve had any other issues pop up since the repair was done? My mechanic mentioned it could also be head gasket related but Im not convinced. A compression test seems like the logical first step based on your experience.

After getting the repairs done, everything runs perfectly now. The cylinder pressure fluctuation was fixed when they discovered it was actually linked to an improperly installed spark plug from a previous service. They also checked the camshaft and intake manifold while diagnosing, but those components were fine. Since it was a consequential error from their previous work, the repair was completed at no cost (0€). The turbocharger response is back to normal, and fuel consumption returned to standard levels. No additional issues have emerged in the past 3 months. A compression test is definitely the right starting point. Based on my experience, I would be skeptical about the head gasket theory without proper diagnostic testing. The symptoms really pointed to the spark plug issue in my case, though your diesel engine might present different underlying causes.

Thanks for the input. I took my car to a different mechanic yesterday who specializes in diesel engines. The compression test revealed two faulty fuel injectors causing uneven cylinder pressure. They also found carbon buildup affecting the turbocharger performance. The total repair came to 1200€ including: 2 new fuel injectors, Turbocharger cleaning, Full system diagnostic, Labor costs After the repair, the engine runs smoothly again. No more sluggish acceleration or excessive fuel consumption. The mechanic showed me the old fuel injectors which were heavily carbonized. They recommended checking the intake manifold in 6 months to ensure no new carbon deposits are forming. Really glad I got a second opinion instead of replacing the head gasket. The engine knocking has completely disappeared and power delivery feels like new. Thanks again for steering me in the right direction with the compression test suggestion.