How does this cartridge oil filter make a good seal?

[Klutch9]

This is the filter that our Carnival takes. The attached pic is of a Wix, but all of them look the same/similar (some are fully felt on the bottom instead of plastic with a felt washer). I’ve also attached a pic of the housing it goes into, which shows the little locator hole the plastic nipple goes into.

In my last car, the cartridge filter had o rings on the ID to seal against the inner housing, but this style has none of that. The housing doesn’t seem to have any sealing mechanism either. Is this filter always just in slight bypass mode? It’s hard to see in the picture, but the housing has a centering ‘cage’ that the filter locks into so that it goes in straight. That’s all I can see though.

 

[loneryder]

The cap holds it on tight. Mercedes has been using this for years.

 

[Egg_Head]

Similar design as the oil filter for the Hyundai 3.6 motor. Just be sure to use the Mahle branded filter.

 

[KrisZ]

There is also a cap, which likely has a locking mechanism that is on a spring, or perhaps that’s the mechanism at the bottom of the housing. If the oil pressure exceeds the spring pressure, the filter cartridge is lifted up, opening the passage below and thus putting it in bypass mode.

 

[Klutch9]

But what I’m wondering is how does it seal since the one end of the filter has no o-ring or gasket? I don’t think the housing has anything either, from looking inside.

 

[KrisZ]

But what I’m wondering is how does it seal since the one end of the filter has no o-ring or gasket? I don’t think the housing has anything either, from looking inside.

While I can’t tell for sure, I found better pics and my conclusion is that the bottom does not seal except for that little “nub” which looks to be a bypass passage and has an oring.

The base likely has hole under the plate, which we cannot see. The oil flows from the passage on the left, goes through the filter media on the outside and inside the filter and then flows out the bottom. If the filter poses a restriction, it gets lifted up, opening up the port that the little nub lines up with.

It’s hard to draw in 2d, but here is my shot.

 

[Klutch9]

While I can’t tell for sure, I found better pics and my conclusion is that the bottom does not seal except for that little “nub” which looks to be a bypass passage and has an oring.

The base likely has hole under the plate, which we cannot see. The oil flows from the passage on the left, goes through the filter media on the outside and inside the filter and then flows out the bottom. If the filter poses a restriction, it gets lifted up, opening up the port that the little nub lines up with.

It’s hard to draw in 2d, but here is my shot.

View attachment 334028


View attachment 334029

It’s certainly possible. I appreciate your observations. That little nub with an o-ring is usually in there pretty tight when I go to remove the filter.

 

[PandaBear]

The Toyota I have use a cap with a spring loaded plate to push the cartridge into the engine side mounting, and the contact surfaces have gasket to help sealing between ID and OD. It doesn't have to be a perfect seal as there is a bypass pressure anyways, and most particles will eventually be filtered over time.

 

[Klutch9]

The Toyota I have use a cap with a spring loaded plate to push the cartridge into the engine side mounting, and the contact surfaces have gasket to help sealing between ID and OD. It doesn't have to be a perfect seal as there is a bypass pressure anyways, and most particles will eventually be filtered over time.

From what I’ve seen, the filter cap doesn’t have a spring to push the filter in. Or maybe there’s something I’m not seeing. I think the cap does have some sort of bypass though. At any rate, it doesn’t matter, as I know the filter functions properly. I just think about these things all day long haha.

 

[PandaBear]

From what I’ve seen, the filter cap doesn’t have a spring to push the filter in. Or maybe there’s something I’m not seeing. I think the cap does have some sort of bypass though. At any rate, it doesn’t matter, as I know the filter functions properly. I just think about these things all day long haha.

It is hard to see on the Toyota, but if you put a filter on the cap and push down it will spring inward.