If it does not do it on motor and only when using the spray...then the first thing that comes to my mind is blow by.
What are you using to vent the motor?
...PCV valve, breathers, vacuum pump....????
You are most likly leaking oil out by the dip stick tube along the side of the block on the drivers side. Take a look.
Keep me posted, I believe this can be fixed quite easily if there is no engine damage or excessively worn rings.
Later
|