bradleyj
Member
I've got a '97 Passat TDI that just reminded me of a cold weather problem I was having last winter that I never got around to addressing. When air temperatures are below about 15°F, acceleration is terrrible. Almost like having no turbo. I get no CEL and no visible smoke. The engine runs smooth but with very little pickup, especially at mid-range rpms. I can hold highway speeds on a slight upwards grade but anything more and I lose speed. Acceleration from a stop is better (not normal though), but once I get past about 1500 rpm, it drops off. The really funny thing is that this only starts happening when the engine has warmed up to operating temperature. If it's 10°F outside in the morning I start the car up and it runs fine until the engine has warmed up, then the acceleration goes away. When the outside air warms up during the day, it runs fine. Like I said, the outside air temp where this starts to happen seems to be about 15°F. Any ideas on this?