What could be a problem for a 2015 VW 1.4TDI lossing power
I have sent my car to VW wherein they changed the MAF sensor the previous year, the problem persisted on the second year and VW technician then changed the turbo as it was still under warranty. The problem still persist and it has been worse after a traveled from Gauteng to Limpopo this weekend. What i noticed was that, when i stop and shut down the engine, the problem goes but after driving for like 20 km the problem comes back. I lost faith and would not want to go back to VW for assistance as they seemed to be not sure of the cause.
Cars & Trucks - Volkswagen
Answers & Comments
I had a similar problem with a much older VW. I found that if I would loosen the fuel filler cap slightly, I would hear a hissing sound of air and power would return until I had driven some distance. This was caused by the fuel tank ventilation system not allowing air to enter the tank as fuel was consumed. This can cause enough of a vacuum in the tank to prevent fuel from reaching the engine. Stop the car (with the engine running) and slowly remove the fuel cap. If you hear an air rushing sound, that is the problem.