With the weather changing, I figured this would be a good time to get this leak fixed, since I run 10w-30 in the winter and from experience, it leaks a lot faster than 20w-50, which is what I've been using as a summer oil. The oil cooler lines leak (I believe the first time I had the oil changed, that the mechanic I had do it smacked one of the lines while getting the filter off) and oil isn't getting any cheaper. So, I have the bypass elbow, the connectors and the 4 o-rings. Is there anything else I'll need to do this or this all I need?

 

Of the top of my head, the only other thing to have on hand is a fresh tube of Permatex Ultra Grey RTV silicone sealant, unless you have a new gasket for the oil filter housing. Check the other common left side leak points while you're there. The photos at the link below may be helpful:

Welcome to Jag-lovers - Members Photo Viewing Page

Cheers,

Don

 

The oil filter housing does not need to be removed. The lines and cooler can be left in place and the lines pushed out of the way and secured.

It is a neater job to remove everything but it is not necessary.

bob

 

While the due date for an oil change is around the corner, I'm thinking of disconnecting the lines while the filter is off (I take out the air intake plumbing for better access to the filter) and then, get underneath somehow and cut the lines as far up as I can get so that they're out of the way, and won't flop around and possibly break something else. Even if this isn't the only source of my oil drip, installing a bypass will definitely slow it down..and eliminate the hot oil smell I get whenever the warm oil starts to pass through the lines

 

Since the oil filter housing mounts with just four screws and is a common source of oil leaks, in my humble opinion it would be short-sighted not to remove it while you have easy access, clean the mating surfaces and seal it with a good bead of Ultra Grey. It will also be easier to install the connectors and bypass elbow with the housing removed.

I'd also recommend that you address the oil filler tube housing, and the dipstick tube seal (which you can probably just replace with a piece of rubber tubing from an auto parts store).

Having a leak-free XJ40 is a wonderful thing - now's your chance!

Cheers,

Don

 

Very true. I have limited tools, but that hasn't stopped me before! It's dark now here in Illinois, but tomorrow morning, I will see what I find. Is very reassuring knowing that there's people out there that have plenty of knowledge on these cars, everyone here in my town is afraid of it (and claims they can't find parts...), so I usually end up doing my own work, unless it requires the entire vehicle coming off the ground!

 

The bypass is in, but now I can't hold oil and I lose pressure constantly. Car is not drivable. I used the right size o-rings on the bypass too

 

So when you say you can't hold oil, do you mean it's leaking out? at the bypass? There are four o-rings in there, two on each bypass cylinder BTW

Larry

 

It holds oil as long as the engine is off. Once I try to drive, I lose all my oil pressure and it starts streaming out of the bypass. I have the proper o-rings where they need to be, but it seems like they are too small for the cylinders..

 

Upon closer inspection, I found that the cylinders for the bypass fit in the housing very loosely, and the oil cooler lines were nice and tight. A note: when I was loosening the nut for the lines, the feed line wasn't in all the way, therefore causing a leak. Can anyone say sabotage? When I first got the car, the lines didn't leak. But the leak started after I had a shop change my oil..luckily I hadn't been back since but that's still crazy. I damaged the nut trying to re tighten the bypass earlier, so I'm getting a new one, but I'm just gonna put the lines back in and see what happens.

 

Yeah, the oil cooler lines are back in, but there's a hemorrhage somewhere, cause I have no oil pressure and the car just pees out every drop of oil in the motor..

 

How do the O-rings you used compare to the ones shown below:




There's nothing special about the O-rings, but if you can't seem to match up the correct size, they may still be available from Jaguar, part number CAC5118.

Cheers,

Don

 

They tightly fit the cylinder connectors, but are only half the thickness. They're CAC5118 rings, but I can't figure out why mine look different, and why the cylinder connectors don't fit as tightly as the cooler lines

 

Weird.

 

Ok, in my experience the o-rings are a pretty tight fit and as far as I can tell there should be no way they could leak.

Here's my unit and the replacement procedure - I had the wrong size rings at first but even those didn't really leak - however, the "wrong" ones were only a temporary fix after breaking a couple so as soon as the right ones arrived, they got replaced.


Are you using used or new o-rings?? old ones could be compressed and unable to seal.

here's my replacement thread with a few pics...

https://www.jaguarforums.com/forum/x...2/#post1332052


Larry

 

My o-rings are new, and this is what they look like

 

Those are definitely too small in cross-section. They should be two to three times thicker.

 

...not only thicker, much "fatter" too! - when fitted they have a larger diameter than the cylinders.

Someone supplied you with the wrong parts, as Don said they are way too skinny! Correct ones fill the recess completely ...no wonder you've got a leak!!

You can buy the correct o-rings online for as little as $1.25 each, I think I got mine from car parts discount (no affil)



Larry

 

When I found the ones I got, they were about under $1 each or so, I don't recall the exact price. Will be getting the correct o-rings and a new nut (cause I damaged the original) and try again as soon as I can. I am also going to look in as far as I can to see if possibly the gasket on the oil cooler adapter or the gasket between the adapter and filter plate are damaged. Luckily I had this problem in town instead of on the interstate!

 

New o-rings are on the way and I managed to find some M8 Nylon lock nuts at my local hardware store (bought extras cause I know I'm gonna drop at least one..tight fit but not impossible!