My son just bought a 2001 VW Jetta with the 1.8 turbo and 110k miles. Not a bad looking car for the money. Problem is the oil light keeps flashing. He looked on a VW forum and someone else had a similar issue. Revving the engine to 2500 rpm, per someone from the VW forum, made the light quit flashing. It worked for my son's car as well. Recommendations were to 1)replace the thermostat 2)replace the oil sensor or 3)change to a thicker oil. Took it in today and had the oil sensor replaced. No help. It is unknown what weight oil is in there now. Engine specs 5W-40. Car seems to run fine. Can't see any sludge or deposits via the oil fill hole. Anybody have this engine with a similar problem? If so, what solved the problem? Also plan to change the oil with Rotella 5W-40. Anybody got a better recommendation? Any help would be appreciated.