Low-mileage VW Caddy Diesel Shows Engine Performance Issues

Had similar issues with a VW Transporter TDI from the same generation. The symptoms you describe match what I experienced, poor performance and rough running pointed to fuel delivery problems. The root cause in my case was a faulty fuel injector that had been leaking, which then led to carbon buildup and affected the piston rings. This created a chain reaction causing low cylinder pressure. The engine knocking became more pronounced over time. The turbocharger was initially suspected, but diagnostic testing revealed the injector issue was the primary culprit. This type of problem can quickly escalate if not addressed, in my case it required removing the cylinder head to properly assess the damage. Since your vehicle is under warranty, have the dealer check the fuel injection system first. Request they specifically examine: Injector spray patterns, Cylinder compression readings, Turbocharger boost pressure, Carbon deposits around piston rings This is potentially serious if left unattended as it can lead to more extensive engine damage. Have it checked immediately while warranty coverage is still valid. Make sure to get a proper diagnosis with computer readings rather than just a visual inspection, as these symptoms can have multiple causes that are difficult to identify without proper testing.

Just went through similar issues with my Caddy. Once the timing belt was checked, they found the real problem was a combination of a failing fuel injector and carbon buildup affecting cylinder pressure. The turbocharger and intake manifold were actually fine despite initial suspicions. Wondering how much the repair ended up costing you? And has everything been running smoothly since the fix? It would be helpful to know if any other issues popped up afterward, as I am still monitoring mine closely. Would really appreciate hearing about your experience, especially whether the dealer found anything beyond the injection system problems you mentioned.

After getting the comprehensive diagnosis at the dealer, the good news is everything has been running perfectly since the repair. The fuel injector issue was fully resolved and the cylinder pressure fluctuations completely disappeared once they cleaned out the carbon deposits. Since my case was traced back to a manufacturing defect in one of the original fuel injectors, the entire repair was covered under warranty at 0€. The dealer confirmed this was a known issue affecting a small batch of vehicles, which explained the premature failure. They actually discovered the carbon buildup was a direct result of the faulty injector, not a separate problem. This is why they classified it as a consequential error and included it in the warranty work. The crankshaft and other engine components showed no additional wear when they inspected them. My advice would be to keep detailed service records and monitor the engine performance closely for the next few thousand kilometers, but honestly, the fix seems to have fully resolved the issue. The engine now runs as smooth as it should, with normal fuel consumption and proper power delivery.

Thanks for the input. I wanted to share my experience after taking the car to the authorized dealer last week. The diagnostics revealed a faulty fuel injector that was causing uneven fuel spray patterns, leading to the rough running and poor economy. The head gasket was thoroughly checked and thankfully showed no signs of damage. They did find significant carbon deposits which required cleaning, but the turbocharger and other major components were in good condition. The total repair would have cost around 2100€, but since it was covered under warranty, I only paid for some additional preventive maintenance I requested. The service advisor explained that a manufacturing batch issue with certain fuel injectors had been identified, matching what others mentioned here. The car now runs perfectly, smooth idle, proper acceleration, and fuel economy is back to normal. Will keep monitoring but so far very pleased with the outcome. The computer diagnostics definitely helped pinpoint the exact issue rather than just guessing at the problem.