MEP-003A Generator Set Question 2

[DonaldB]

I was wondering why there is a spring and plunger in the center of my oil filter rod (See attached picture)?

 

[PeterD]

Over pressure bypass... All oil filters have these (even spin on ones) as when cold oil viscosity may be too high (oil too thick) to be properly forced through the filter element. This allows thick, cold oil to get to the engine instead of being stopped at the filter!

 

[Speddmon]

Also allows the engine to get oil in the case of a severely plugged filter