The crank case vent which is on your cam/rocker cover should be plumbed into your intake. If you start revving it hard, particularly if the engine is getting old, the crank case will pressurise and force the air through this breather into your intake. This air will contain oil fumes which condensate in your intake.
The reason why it is plumbed into your intake is because it is illegal to have it venting to the atmosphere (don't want to get oil on the road).
The oil will hamper the performance a small amount, but not much.
If you want it to stop, change your driving habbits or install a filter.
Tue, 18 November 2003 23:28
