Questions and Answers

Volkswagen Jetta Gas In Oil Q. I have a 1989 Volkswagen Jetta, 1.8 liter, manual transmission, 243,000 miles with a Digifant-II management system. The problem is when the car comes up to temperature in 20 minutes the oil pressure buzzer comes on and the light comes on. I have no blue or white smoke. The oil has a gas smell.

I have checked out the fuel injectors and I have replaced the fuel pressure regulator. I have checked out the fuel pumps and relays. When I changed the oil, the viscosity was extremely thin. After driving it for 700 miles the gas in the oil problem has repeated. How is the fuel getting into the oil?

Thank you,
Jay

A. The Digifant-II Fuel Injection is a mechanical fuel injection. That is to say that it has a fuel distributor much like the ignition distributor and mechanical fuel injectors.

The fuel Injectors have no metering function, they open when the fuel pressure in the fuel line exceeds their pre-set opening pressure of 44 to 59 psi (3.0 to 4.1 bar). Over time these springs get weak and the injectors start opening sooner and stay open when the engine is off.

There is a special injector tester that pressurizes the injector and shows exactly how much pressure it takes to open. This is the only reliable way to test the injectors.

I don't see any other way fuel can get into the oil.

Fuel Injector

Fuel Injector Pressure Tester