Originally Posted by Louisianagames
I'm with Ya on the wix filter. I use them In My boat twin GM 502's .
The valve is designed to let the oil bypass the contaminated filter when it gets full and keeps it from going back into the engine.
We have a tool to cut them open to see what might be getting destroyed inside the engine (different types of metal)
Take a peak //http://www.wixfilters.com/productinformation/index.html
Well, you are talking about the pressure bypass valve, not the ADBV. 2 different things!
So where does the oil go when the filter is full, if it doesn't go back to the engine?
Interestingly, GMC tends NOT to have a bypass valve in the filter, but usually uses them in the block instead!
NAPA Gold and CarQuest Premium are the SAME filter as the Wix, with a different paint job.