I have recently purchased a genuine oil filter ECB9658 (fits original XJ6 series 3 through to X300) & also have a Fiaam/Coopers FT5925/Z509A aftermarket filter.
Looking at them I believe the oe filter is probably made by Fiaam/Coopers.
What I am perplexed by is the design of these newer filters. The centre tube is neither perforated or louvered to allow the filtered oil to pass through to the centre. They have a solid centre tube & it appears the filtered oil enters the centre section via a gap at the bottom. All previous filters & in fact oil filters for most other vehicles have a filter design with a perforated /louvered centre tube.
Can any one explain this difference & perhaps the advantage over the more conventional design.
It does appear this design is unique to Jaguar.

 

Well, it's not unique to Jaguar, but it does indicate a better than run-of-the-mill filter. The center of the filter is not perforated because the filter is designed with an "anti-drainback" or "anti-siphon" valve inside. That should be in just about any filter intended to be oriented on it's side. That prevents oil in the engine from siphoning back into the sump when the engine is off. If it wasn't there, most every start would be basically a "dry" start, and the oil pressure [and oil] would lag for several seconds at startup. That would greatly increase engine wear simply from starting up.

Take note, if you see those perforations or filter pleats by looking inside an oil filter.......don't put it on your Jaguar engine. That goes for the V12 as well.

Hope that helps!

 

Steve, I believe you are a little confused with my enquiry. The "anti drain back valve" is a nitrile or silicone (preferred) gasket just under the inlet holes at the top within the gasket. Most filters these days have them. What I am referring to is the metal centre tube which in most filters (previous Jaguars oem ones also) the metal centre tube is perforated/louvered as shown in the picture/diagram attached.

 

Something is not right.

A search using "solid center tube" "oil filter" brings up exactly TWO results. This thread being one of them.

You would think that if it was a normal practice there would be more results than that.

Maybe a bad batch got out.

However, searching on the part name/number brought up:

Print Page - oil filter

It may what is referred to in that post as a "internal shield" because on the Lancia Gamma the filter seems to be mounted base down and it holds the oil in. Sort of like the overflow tube in a toilet tank. You would have a larger diameter perforated tube around the smaller inner shield.

 

I can only go with what I know and what I was told. The EBC9658 filter and it's predecessor, which as I recall was EAC1467 and about 1 1/2 inches longer, both have always had a solid center tube. The later and current filters have all been more as you describe. As most texts allude, there are numerous variations spec'd by OEM's; and not all anti siphon valves are the large nitrile version as the illustration. Back in the day the explanation from Jaguar about the center tube was it was because of the anti-siphon valve and the "longer" oil path through the filter material it provided.

But we CAN agree on the possibility that is another load of bull spewed to silence a few inquisitive technicians, yes???

Cheers,

 

I also have a 1980 series 3 XJ6 owned since 1991 & over the years used Crosland filters which I believe also made the OEM ones. Yes these filters were longer however they did have a perforated centre tube & a anti drain back valve. Just when Jaguar changed to the solid tube design I'm not sure.Crosland filters have I believe been taken over by the SOGEFI group who make the Fiaam/Coopers & others.
As you mention, this design provides a longer path for the oil to flow through & this I believe is their main reason for this type of design. The oil has to flow downwards through at least approx. 7cm of filter element before it starts its path up through the centre & back into the engine as opposed to travelling through just 1.5/2 cm of element, through the perforations into the centre tube & back into the engine. It does thus appear that if the bypass valve at the bottom of the filter activated (clogged filter) the actual centre tube would move downwards to allow the oil to pass straight out at the top to the centre outlet hole.
The anti drain back valve in these filters appears to be a white rubber/silicone diaphragm visible under the 8 inlet holes at the top of the filter.
I think their main design intention with the solid centre tube is as you mentioned, the longer filtration path for the oil.
Thanks for your input.

 

As I had a spare filter it seemed the only course to satisfy my query was to open up a filter. All was revealed.
Photo 1 shows the filter element & white rubber ADBV as lifted from the cannister.

Photo 2 shows that hey, it is only a normal design filter element (82 pleats for those interested) with the usual perforated metal centre tube like all filters.
What is different though is the attachment of the rubber ADBV to a black plastic tube that sits down within the metal perforated tube. It stands proud of the perforated centre tube & extends to about 8/10mm from the bottom where the oil escapes & up through the plastic tube. What benefits this brings I do not know. Majority of filters seem to just mount the ADBV on the top of the stamped top cap hence when looking down the centre the perforations are visible.
The filter unit appeared of sound contruction with a strong Baseplate & thick cannister walls. The usual BY Pass Valve was fitted at the bottom.

 

Thanks for taking one for the team

Maybe it's anti-turbulence, anti-foaming or to distribute the flow across more of the media rather than concentrating it at the point of least resistance.