Hello...
I'll try to be concise. I have had a 99 Jaguar XJR since September of last year with 74000 miles. Since then I have had fuel pumps replaced, valve cover gaskets and spark plug seals and plugs replaced and I have recently replaced a radiator, waterpump and thermostat. The car runs very smooth with plenty of power. My problem is that I have also replaced 3 air filters since then because of oil backing up into the air box. The oil also travels up into the throttle body which cause smoke to come out the exhaust when I first fire her up. If I clean out all the oil from the breather box and throttle body, it takes a couple to three weeks for this cycle to start over again. Some times it smokes sometime it doesn't and the severity varies.I've read the the culprit could be the load breather tube being clogged or cracked therefor not creating a vacuum to keep the oil in the motor. So I ordered the load breather tube and now have no idea where this puppy goes to. It seems to go underneath the super charger to god only knows where. I need help in understanding where it goes, at what three points does it attach and instructions on its replacement. Do I have to remove the intercooler and supercharger to replace this simple part? Thank you in advance for any help and guidance.

 

Hey I have an xkr same year and was wondering the same question as to how what needs to come off or un done to install the new tube I got the diagram from the dealer but it didnt show the super charger and it defenitly seems like its in the way???????????

 

Well, reckon I'm a bit disappointed..no response..

 

I am not sure what you need to do to replace that hose but my guess it is not easy. As for the part load breather being clogged you need to check it and clean it regardless on it being related to the oil in the breather pipe.
Now for the oil in the breather pipe! This is caused by blowby in the cylinders, this can be controlled at times by the viscosity of the oil you are using and or using an additive or both. I must assume that your car is a v8 (XJR) it being a 1999 I must also assume it is a Nikasil block. This is not a bad thing it is just a matter of understanding it and knowing what you have and what to do to finesse it. Please read my information on Nikasil when you get time http://www.gusglikas.com/AutoRepairNikasilSulfur.htm I had a conversation with one of our respected members (Brutal) that once suggested using an additive in the oil and I must say I agree with him. It was the best thing I did for my Rav4 that has over 265,000mi on it (I hope to get to 300,000). Now do you need to do this? Maybe not! It all depends on the oil that you are using 5w-30w maybe a bit thin and you may need to move up to 10w-30w or 10w-40w I had a 93 XJs that I had to do the same thing. Consider it and let us know if we can help.
PS: Today is Sunday (football night at home)

 

It very well may be obscured by the supercharger. If you can locate both ends of the secondary breather tube, one going into the throttle body the other emerging from the camshaft cover, then detach one end of the old hose tie it to the new one and use it to feed it under all the supercharger/intake manifold stuff.

I hope it cures the problem. Going up to a thicker oil is also a good idea. Jaguar allows up to 15W-50 if synthetic, though some old hands use 20w-50 synthetic. Synthetic will help dissolve piston ring deposits which may be preventing a good seal. Synthetic 10w-40 (as opposed to 5w-30 semi synthetic blend ) has worked for me to greatly slow down some oil consumption.

 

Dan R is right, you can feed in under the supercharger . However, I very much doubt that is your problem. Read Gus'es writup about blowby.
And Dan- I am encouraged to read your theory about synthetic freeing up rings. I am about convinced that happenned on my beater XJR with 235,000 miles. It went from using a quart of oil every 1 to 2 thousand miles to one in 4 to 5 thousand or so, after the second change of Mobil 1.

 

The tube feeds under the supercharger to a t-fitting. The t-fitting connects to a short 2 inch hose fitted to a nipple on the lower throttle body (and virtually impossible to get to the little sucker without removing the top half of the throttle body. The other hose off the t-fitting goes under the throttle cable to a wired plug on the firewall.

 

Thanks to everyone who responded...I hope to try to get it switched out in the next couple of weeks. I notice the excessive oil in the airbox after switching to synthetic 5w-30 mobile 1. Should I try sticking to synthetic and go up on the viscosity to help with this issue or go back to conventional oil? I do know though that the breather hose needs to be replaced as its being held together by electricians tape. I unclogged the breather at the valve cover and it cracked when trying to reinstall it :-(. I'll report back on any success or failure..Thanks again.

 

Here's my tuppenceworth... I changed my part load breather pipe by taping the new one to the old then gently feeding it through, small hands help for refitting to the throttle body (I used my wifes' she is very good that way....)
Since then I've fitted a one way valve from a Ford Cosworth (turbo) to the part load breather, to stop the supercharger pressurising the crankcase. Then I put a catch tank on the full load breather side, so far the inlet has been staying oil free and strangely the breather tank doesn't seem to be filling up with oil.
I use fully synthetic 5/30w oil. Before I did all this there was what I thought to be a lot of oil in the intake and my car would smoke when first started if parked on a slope (?), I took it to my main Jaguar dealer for advice and after looking at it they told me it was normal (!!) but I'm fussy.
By the way my car used to be sluggish but since the oil in the intake was removed it became much more lively. My compression pressure on a hot engine with wide open throttle is 150 psi on all 8 cylinders, the bores also looked factory fresh when recently I had the head gaskets replaced so I can't see that the Nikasil has anything to do with it.
I'm not suggesting that this is the answer but it seems to have worked on my car.

 

Stew52,

I like your idea and w0uld like to implement it along with all the other tips. Could you post some pics and perhaps some part#'s so I can duplicate what you have done? I'd be excited to get this problem solved once and for all!