Jerry and Spencer--

Well, you can see from the image I posted that the filter I cut open has a blue like color, so may be the same as yours. Truth is, I was given this filter along with an oil cooler and base so I don't know it's origin.

I am not using this type filter on my engines any more as I am too cheap to buy them. I have converted both of my C223's and my son's to use the filter from a VW diesel which is about $5. It has only the full flow filter and is probably not as good as the Isuzu unit. I change the oil & filter every 3000 miles.

The VW filter does have a second valve inside opposite the threaded end. It is a pressure operated filter bypass valve, put there (I presume) in case the filter might get plugged up.

Worth noting here is that the earlier Isuzu engines (about '82 and before) used filters very similar to the VW filter.
I think they added the bypass filter when they added EGR to the engine.

Yeah, I wouldn't cut open a new one either.

Paul <img src="/forums/images/graemlins/cheers.gif" alt="" />