Originally Posted By: DBMaster
"Suction" is really a myth. With a vacuum cleaner you are creating an area of artificially low, or negative, pressure. The "suction" you feel is air at normal atmospheric pressure rushing in to fill the void. So, what they are doing here is preventing air from filling the void left behind by the oil.
If an airplane door is opened at altitude, things do not get "sucked" out of the airplane. They are pushed out by the higher pressure inside the plane compared to outside.
Whatever the technical terminology is, if you put a vacuum on the oil fill of an engine, and pull the drain plug, you will be able to see and hear the air bubbling through the drain hole and into the oil pan.
Originally Posted By: JHZR2
Originally Posted By: Vikas
Originally Posted By: JHZR2
Clever. Wouldn't running the engine do the same thing, at least on a gasoline engine?
You were joking, right? Are you implying that if my drain plug came loose and came off during driving, I won't loose any oil until I turn off the engine?
You can read, right? I did use a question mark, didn't I????
Is the crankcase under vacuum when an engine is running?????
Not in the least.