My '99 XK8 vert is sucking oil into the intake tube as well as the air cleaner and I've checked for a missing valve cover baffle on the full load breather side--- still there... as well as making sure the driver's side orifice is clear...it is. I'm still getting excessive blow-by by my standards and the accumulation in the throttle body and plugs certainly can't be a plus for performance even though the car runs well when it's in the mood.

I can probably figure out a way to jury rig a catch can but would be interested in anyone who may have already done so on a similar model XK8 w/o SC since I'd want to catch the oil BEFORE it gets to the main air intake.

 

Sorry no, but I started work on my 1999 XK8 4L naturally aspirated engine and found a problem with PCV connection to the air breather pipe to the air intake tunnel. As you're in USA, you may have a different car spec to mine ie I take it you have the EGR as mine doesn't as USA emissions regulations are stringent.

I would be more concerned with the source of the oil - your excessive blow-by and the fact your breather hose must be wet with oil. Could be worth taking the cam covers off and checking oil isn't ponding due to blockage somewhere and checking the seals around the spark plugs. It wouldn't be the first time, someone left something where they shouldn't inside the cam cover.

Hopefully others on this forum may have other ideas specific to USA spec. cars.

 

Thanks for the quick reply. My U.S spec'd car doesn't have an EGR valve. I've had the cam covers off twice over the last 1+ year; first to replace all the tensioners and cam chains and then to seal an oil leak at the backside corners where the valve cover gaskets had not been properly installed. At both times I replaced the O-ring seals around the sparkplugs. I also checked the oil baffle on the passenger side part load breather as well as making sure the one on the full load breather was not blocked. Aside from the possibility of blow-by caused by a failure of the nikasil treatment of the cylinder bore it seems that this problem is fairly common on at least the early 4.0 engines.

Since the engine doesn't appear to otherwise be burning oil and the performance is still plenty adequate I'm in no hurry to remove the engine and send the block of to be re-done by one of the many companies offering a replating service. I don't love the car THAT MUCH

 

Oil accumulation in the throttle body will be caused by the engine breathing, but oil around the plugs is just a leak. Those gaskets for the spark plug holes just don't seem to seal very well. Like you, I've replaced them and still get oil accumulating down there. But if it was caused by excessive blow-by, you'd also see oil leaking from other areas of the cam cover, likely onto the exhaust.

I wouldn't worry about it.

 

A compression check will be useful.
Low compression due to poor piston ring sealing will result in blow by during engine operation, increasing pressure in the crankcase.

 

 

RD Minor,

This thread is a month old, so I've no idea if/how you installed the oil catch can. I was looking at this old thread (2016) on a catch can on a 2003 XKR, and thought it might help you. I know you have a 1999 XK8 convertible, so the internal set up would be somewhat simpler in our cars.

https://www.jaguarforums.com/forum/x...ch-can-160598/

The strange thing is that the cam cover does come with a simple oil separator under the full load breather, which is just wire wool under the steel plate.

Simple but effective.

I would check first if someone has damaged this integral unit and/or even taken this out.