Hello guys,

I've been getting some oil in my intake tube, air filter and on down to the throttle body. Not a lot...about a tablespoon distributed throughout the intake at any given time...but it's enough to **** me off a bit and it dirties the throttle body opening.

The engine shows great power, and the Nikasil / blow-by issue has been checked with no bad news. But I want to stop getting oil in my intake system.

So here's my issue: When reviewing JTIS (and several other technical write-ups from Jaguar on the AJ26 engine), they mention and show several times that OIL SEPARATORS are installed in both valve covers, below the orifices for the Full-load and Part-load Breather tubes. Quoting JTIS, "each camshaft cover oil separator consists of wire gauze packed into an open ended enclosure in the top of the cover, below the breather outlet."

The intent of these separators is evidently to allow the passing of normal air flow through the crankcase (along with normal blow-by), without oil getting up into the Full-load and Part-load Breather tubes.

I've attached an image from JTIS that shows one of these oil separators in place. When one pulls off the Full-load Breather tube on the right-hand valve cover (the tube that also connects to the the air intake system...one should see a metal plate or wire gauze...that's the oil separator, and it's preventing oil from splashing up into your tube.

I DON'T HAVE OIL SEPARATORS in my valve covers. When I look down into my Full-load Breather orifice, I see camshafts. So evidently, perhaps with higher revs and normal blow-by, a bit of oil is splashing into my Full-load Breather tube and then dripping down into my intake system.

One respected tech on this forum has told me he doesn't normally see oil separators in AJ26 / 27 engines. My local tech, however, says he sees them often. In fact, while we were on the phone yesterday, he went out to check a 1997 XK8 in his garage and when he peered into the Full-load Breather orifice, he saw a metal plate...not camshafts. That engine had a separator in place.

I would greatly appreciate it if some of you guys could take a peek into your Full-load Breather orifices and let me know if you have oil separators in place. Just be careful with the connection, and don't force it. If you pull the tube off and see a metal plate or wire gauze, you've got oil separators. If you see camshafts, you don't.

If oil separators are common, and I just don't have them, I'll be looking to replace both valve covers soon with separators in place.

Thanks for listening, and for any wisdom you can provide. I love this group...I wish we could all meet up and talk Jags for a few hours.

- Scott

 

The oil separators were in place at the time the valve covers were off to do the tensioner replacement. - 2001 XJR.

It's like a stainless steel pot scrubber sandwiched between a plate and the valve cover under the breather openings. The plate is say ... 5 inches square or so.

 

My 02 XKR Coupe has them also... I saw them when I had the covers off for the tensioner change.

 

Thanks, plums and pomosv. I appreciate the quick replies.

I'd love to hear from more of our guys...what about those of you with earlier XK8s? Do your valve covers have oil separators in place?

 

The AJ27 for sure, and have also seen them on the AJ26 SC cars from 99.

 

My 98 has them. Same story...I noticed them when doing the secondary tensioners.

 

Update:

I got a look at an old valve cover from an AJ26, and it's got the oil separator in place below the full-load breather opening.

Don't know what happened to mine...either it didn't come with one (my XK8 is VERY early), or some tech removed it at some point. In any case, I'll definitely be taking care of that problem soon.

I don't imagine it would be a good idea to try and fit an oil separator to my existing valve cover...probably should get another one that already has the oil separator in place.

Any other owners of early XK8s willing to tell me if they've got oil separators in place? Or any of our techs willing to share some wisdom?

 

I need to look at mine but based on my oil consumption and the amount of oil I usually see in the manifold under the throttle body, I'm going to say I'm missing any oil separators in the valve covers. I was going to build an external one similar to what we used to have on light aircraft with the old wet vacuum pumps (with a catch bottle under it) just to see what the volume of oil is that is transferred by the breather lines.

 

I had my valve covers off during my timing gear change, and the L/H side breather plastic outlet was damaged. I removed the cover on the breather, removed the breather metal mesh, cleaned the area, machined a new outlet from brass to match the original fitting, drilled out the old fitting, and epoxied the new one in place. I just clipped the breather hose on it and it fits fine.
The breather cover can be removed from inside the valve cover by VERY CAREFULLY bending the tangs on the metal plate, and then removing it. The pads will then just fall out. Straighten the tangs on the cover plate, again VERY GENTLY, and they are ready to reinstall. When they put the pads in originally, they just layed the pads in the cavities, layed the cover plate in position, and then pushed the cover plate down. Just doing this, bends the tangs and locks the cover in position. So it is not a big deal to take them on and off.
You might want to look on the inside of your valve covers and see if the plastic molded area is present. If it is, then they must have forgotten to put in your pads and covers. See if you can order the parts. If the covers are off, it is only a 1 minute job to install them.
Again, you want to be REALLY CAREFUL when you work on the covers. My local parts guy quotes themat $270.00 each, So asked how often they get ordered, he said
"All the time! They have a real problem with warping"
When I put my covers back on after the timing chain replacement, I was very careful to torque them in stages, and used the proper torquing sequence.

 

My 2000 XK8 has them.

 

An UPDATE:

I popped off my original right-side cam cover to see if it has the pegs in place for fitting an oil separator...it does not. Strange.

So, I've ordered a new cam cover from Gaudin, $ 183, and they have confirmed that the new cover has an oil separator in place under the full-load breather orifice. Once I've got it installed and I (hopefully) notice that much less oil is making it into my intake, I'll post some kind of informative thread, with pics.

But first...while the cam cover is off...the tensioners. I was told this car had the second-gen tensioners installed...they sure look first-gen to me. In any case, the latest-gen tensioners are on the way.

Thanks for everyone's help.

 

Ancient thread! I have these separators.
1997 XK8 convertible