I have a diesel ride and here are some of the observations:

1. Oil level increases significantly after a month or so because of fuel contamination. About 4 liters of fuel is being added to the engine oil after 2 months.

2. No overheating.

3. White smoke during start-up, but decreases after a few minutes of driving.

4. With the raiadtor cap removed, water spews out.

5. Water level in the radiator remains the same.

6. No oil traces in the radiator coolant.

Weird?