Oil Filter Leak on Start Up Only

Hello and Happy New Year.
On my XK140, when cold starting I will get a fine stream of oil from the interface of the oil canister and the filter head. It is a very fine stream and stops as soon as the Otter Switch (Hisser) cuts out. It does not leak while driving as the oil level remains very constant even after long drives. Starting oil pressure is 60psi and drops to 40psi after engine reaches temp. I have tightened the snot out of the canister bolt but the situation remains. This does not occur on warm starts.
Appreciate any thoughts.

That 20psi difference is apparently enough to cause it to seep. It’s messy to deal with but make sure the canister top edge is perfectly smooth and flat and pulls all the way up into the recess in the housing without the o ring. I was dealing with a similar situation years ago where someone in the past had resurfaced the top edge of the canister, effectively making it shorter, and the big bolt was bottoming out in the threaded sleeve at the bottom of the canister not allowing the canister to compress the o ring sufficiently.

I cant help but think maybe the internal components are no longer serviceable or incorrect. Also perhaps some grit or other debris around the rim is stopping the cannister from seating on the head cleanly.

At the very least the rubber gasket washer in the rim would be worth replacing.

Also, I don’t know much about these but I read recently the flow through pressure can be changed by making an adjustment on the head of the filter assembly. From that I understood the return pressure setting of the oil can be raised or lowered presumably to deal with exactly your sort of problem.

While you are in there make sure that there is only one o-ring in the groove. The groove is quite deep and sometime in the past someone may have mistakenly left the old o-ring in there and put a new one on top of it. Also, if the square-section o-ring is too narrow it can be twisted within the groove and not seal correctly. By undoing four bolts and the oil pressure line you can remove the filter assembly from the car and inspect and work on it while standing up.

I think a couple of people have reported finding this DPO error.

Agree, much easier on the workbench. You can check the surface condition of the groove. Also check for scratches and gouges in the edge of the canister.


Thanks for all the responses but all the suggested issues have been addressed. I had the head off the car, only one new O ring (proper size) installed, canister edge free of defects, internals cleaned or replaced. I am curious about the possibility of the bolt bottoming out and will add a spacer between the bolt head and sealing washer-perhaps (hopefully) that might resolve it.

Should be a flat washer and a sealing washer on there


And the canister can get dimpled in due to overtightening.

Alan, if you install the canister without an o ring (leave out the filter to simplify things) and hand tighten, the canister should top out in the groove in the housing, that will ensure enough pressure will be applied to the o ring when installed.

Continuing with my oil canister leaking problem, I have followed all the suggestions from this post and ran leak free for quite some time. But now I’m finding that the bolt (my model has the bolt inserted from the bottom and screwed into the head) will gradually loosen causing the seal interface to leak. I have the sealing washer and a flat washer, as Rob suggested, and I tighten the bolt to what I consider very tight. Is using a locking washer under the bolt head a solution or is there another possible issue?

This tells us that your oil filter assembly is not the original for XK140.
We’ll need a photo or a model number off the unit to figure out what it is from.

I do not have Label or model number on the filter. Viart indicates that on xk140 engines number G-6233 and subs had Tecalemit FA 2708 which was an underneath securing bolt. My engine no. is G-69823, so I believe the filter assembly is correct for my model
Photos attached.

Try a thin rubber o-ring between the long bolt and the washer at the bottom of the canister.

My mistake, you have FA.2708, the one not listed in the 140 book, but shown for late Mark VII, Mark VIII and Mark IX.

Item 17 is a sealing washer, Jaguar part 6296 or Tecalemit part 137487.
Your local hardware store will have washers like this in drawers full of faucet repair parts.

If you have a lock washer only under the securing bolt you will have a leak. What you need there (#17 in Robs illustration) is a fiber, soft copper or aluminum sealing washer to handle the torque required to tighten the canister sufficiently to compress the O-ring at the top. A rubber washer will deform and split with the torque necessary to compress the upper O-ring enough to seal the assembly. A rubber O-ring would work but it would require a recess shaped to match the cross sectional shape of it whether it be square or round in either the canister base or the flange on the bolt.

I was able to tighten the bolt considerably more. I had installed a new O-ring and the initial tightening sealed it for awhile. Perhaps the O-ring needed a better set. At the next change I will install a wavy spring washer between the bolt head and flat washer.
Thx for your suggestions,