P38 Diesel

BAZZ said:

Hi all, hope everybody had a good holiday. Iam haveing problems with the oil filter cap leaking, only does it after a long run or towing when engine is working hard. Have replaced the filter housing and the cap, the later several times. Still leaks oil. Thinking of buying the BMW parts just to see if they work any better. Any help is appreciated thank you, Bazz.

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Datatek said:

The replacement O ring that comes with some of the filters is under sized. I had the same problem, bought a different oil filter kit and the problem was solved.

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Speedex750 said:

I've used a few different makes of filter but never (I know that's tempting fate) had a problem. I put the cap back on with a chain wrench and can feel the extra tightness as the O ring enters the housing. A little oil on the ring helps prevent tearing and lets it settle in the right place. I know there's an early and late filter, if your engine has been changed have you got an early engine in a late car or the other way round - and could be fitting the wrong filter - if the seal is different?

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Speedex750 said:

Yes, my cap has a hex but it’s really thin plastic and looked like it would shear easily with the torque needed to get the ring to enter the housing. A chain wrench just above the thread works fine, besides I haven’t a socket that size!

I guessed that the filters were different but are the O rings and is the wrong one getting fitted? I recall other threads about leaking caps. Perhaps we should resort to engineering and measure up the housing and groove and see if the supplied ring is sized right? My next change is a few weeks off and I’ll try to get some measurements.

Both my sons have BMW Z4’s and Forum’s for them list the O ring sizes for everything, perhaps we should have something similar for the P38? I know you can probably get O rings from LR – but maybe not all of them when they come as part of an assembly and that doesn’t help with these sorts of problems? Then you can always get one locally when you’re stuck.

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Speedex750 said:

Yes, my cap has a hex but it’s really thin plastic and looked like it would shear easily with the torque needed to get the ring to enter the housing. A chain wrench just above the thread works fine, besides I haven’t a socket that size!

.

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Speedex750 said:

Yes, my cap has a hex but it’s really thin plastic and looked like it would shear easily with the torque needed to get the ring to enter the housing. A chain wrench just above the thread works fine, besides I haven’t a socket that size!

I guessed that the filters were different but are the O rings and is the wrong one getting fitted? I recall other threads about leaking caps. Perhaps we should resort to engineering and measure up the housing and groove and see if the supplied ring is sized right? My next change is a few weeks off and I’ll try to get some measurements.

Both my sons have BMW Z4’s and Forum’s for them list the O ring sizes for everything, perhaps we should have something similar for the P38? I know you can probably get O rings from LR – but maybe not all of them when they come as part of an assembly and that doesn’t help with these sorts of problems? Then you can always get one locally when you’re stuck.

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Speedex750 said:

I'm trying to help the 'leaky' guy, mines fine. Yes I'm putting the O ring right in the groove. I probably could get the cap on by hand but with oily hands I find it's easier to turn with the chain wrench - I haven't got a scaffold pole on the end, it just helps the grip. The hex on the top looks paper thin, the main body is quite chunky, it all depends where you want to apply torque.

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BAZZ said:

Interesting, have done most of these suggestions and it still leaks after about 3k or doing some work like towing duties. Had a thought of buying the BMW bits just to see if they were any better! The engine was rebuilt at around 67k and as done 30k since it is a late p38 but has the early engine. All ancillaries where swapped over as required even the oil filter housing. It as got to the point were the housing was changed and another new cap as been fitted. The garage and myself are a little stumpped to say the least as to what could cause this but will be looking into blocked filters/breathers etc. Most bits have been from Britpart but i have also fitted Land Rover bits and it still leeks?? Bazz.

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Grit Valve said:

The early type were metal and the late type plastic
The early had the shorter of the two filters .
The hex isn't there to assume how strong it is it there to loosen and tighten the cap

If you over tighten it then you better start worrying
Don't forget the spike has two orings as well.

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