In my last post i found the Air intake system broken, i taped it up temporariliy and went for a drive, ... still oil in the air filter.!!
The previous owner said this oil in the air filter started only 2 weeks ago before i purchased it. He seemed like an honest guy. The car is a 1999 model.. nakasil failiure would have been a steady problem many years ago i think,,, not all in 2 weeks.
The sticker on the front windsheild says the car oil filter has another 10,000 km to go before a change, so its been changed.
I cheked the part load breather tube, clean orifice.
Full load breather tube cleaned too.
I even checked that there is indeed a oil splash plate inside the cam covers where those breather tubes go and that they wernt missing.

Car dosnt blow smoke, it has great zippy speed for 4 liter V8 (x308)

The small part load breather tube , although i checked it to be clean with its orifice, i didnt check where the tube empties out.. where does it go?.. maybe its blocked down the line somewhere.?
Car is great ,just this oil in the Air filter even on a short 10 minute ride.
What can be the problem? It was overfilled with oil by previous owner, now i think its just undeer the MAX dip stick mark, but hard to tell with this car as its so sensiive to how level the ground is.Im sure it is below the MAX mark now.
Its best to check when engine is cold, correct?

Im even toying with the idea of installing an oil seperator , one of those air compressor types or something.. has anyone done this?? Im not sure of the preessure dynamics here either, if the crankcase draws air in via this full breather tube at times, then an the oil seperator may prevent "breathing"... so again has anyone done this modification.
I havnt done an oil change yet but will next week.

Advice appreciated
best regards
Peter

 

oh, i forgot to mention its an x308 Jag Sovereign 1999 4.0 liter V8
best
Peter

 

The closest obvious source of oil is the full load breather which is attached just upstream of the MAF at the airbox.

Check the intake tubing. If it is full of oil, clean it out and watch for a while. It may just be that a bunch of test pilots showed up to drive the car and every single one of them ran it a full throttle during the test drive.

 

Hi Peter
Here is a PDF file with a very fine detailed DIY on cleaning the Full Load Breather, Part Load Breather, Throttle Body, and a number of other maintenance items.

https://www.dropbox.com/s/tf92plcnjb...d.Breather.pdf

Jim Lombardi

 

yes i cleaned the part load and full load breathers... i must check to seee if the part load breather is not clogged way down in the throttle end.
Im hoping that the oil level in the sump is still in excess, but i cant confirm this untill i park it somewhere really flat and level as this car is sensitive about this.
Anyne know of others who have installed an air/oil seperator from an air compressor to the full load breather tube.. i think its my best short term fix.
best regards
Peter

 

I want to thank you guys for your help with this distressing problem!! I have a 1998 XJ8L with 116K on the it and a replacement 4.0L. This was replaced due to timing chain failure from those darn plastic tensioners by the previous owner. The "new" engine had the tensioners replaced with factory plastic tensioners. Actually slipped a tooth on exhaust on the driver side. The shop wanted out of the car. I replaced the tensioners with the help of this forum and onxy and Christopher's parts. The difference was amazing. That was several months ago. Then started with an odd severe hesitation at like 3/4 throttle. No codes. Then this past week restricted performance and the dreaded p125,p127, p1111 codes. Limp mode on and off. Reset and came back on and off. Bought MAF cleaner as that was first step. When I opened the air box the thing was full of oil and the filter was soaked. I am not sure how it was running at all. Heart sank thinking the worst of the replacement engine (rings). Turns out the right sided breather fitting was filled with debris. Cleaned that out with the 3/32drill and then the computer had no idea what was up after all cleaned and replaced. Now runs much better. Should probably do a reset but much better after running it. Thank you all again. This has been a rollercoaster day but ended on a high note because of you all!!!

 

Which fitting was that, exactly, that you unblocked?

 

The part load breather. This is located on the driver side cam cover near front of engine. The full load breather is on the other side. The one I unblocked is very small caliber. It goes under the plenum to the throttle body. The other end is hard to get to, so don't break the tube. The tube/hose becomes brittle with time and easily broken. Then your in trouble. The orifice that gets blocked is in the cam cover. 3/32nd drill is the ticket. Also check the vacuum of the hose by putting your finger over the end you took off with it running. The problem is that crankcase pressure build up if blocked and pushes oil out the large breath tube connected to the intake ductwork on the other side and then oil runs down/backward to the air filter and air box. Then plugs the MAF sensor and you get richness. Sorry for the rambling but helps understand why and where it is.

 

If anyone doubts the validity or wisdom of the part load breather drill bit fix, there is a Jaguar TSB covering it.

 

Great, thanks!

 

Not sure what else to do. Still having oil in air box and filter. I have checked the part load breather tube since and it is clear and suckling when running. I have changed the air filter 2 times due to oil soaking. I have cleaned the air ducts twice and still have this problem. 120,000 miles on a 4.0 1998 XJ8L. I note that as the filter plugs have less power and then rich codes. I really doubt ware as cause due to low miles and really strong performance till the filter fills up. I have another motor but that is a hassle.
This did start all of a sudden.

 

there are 2 breather tubes..to be clear..... 1 big one that connects on the main airflow duct a few inches after the airfilter box
and
a small one on the other side of the engine which is around 10mm perhaps in diameter. Both must me clear, but the last one I mention is more important as it clogs up. Pull the 10mm tube off and insert a small drill tip 45mm from memory .
Important: it must be 45mm... I once "thought " it was clear inside but until I "pressed" it in 45mm, only then did I hear a CRACKLE of soot inside break up and completely clear the tube.
this solved my problem completely.
Something else to check.. I asked myself why did this soot build up occur... it must not have been sucking the excess pressure out I concluded.
So then followed the 10mm part breather tube to the air intake UNDER THE AIR INTAKE MANIFOLD... it snakes under.
I then saw that some grease monkey mechanic has FRACTURED that 10mm plastic tube during some repairs and it was sucking in fresh air through that fracture and NOT excess engine pressure. THATS WHAT ALLOWED THE SOOT BUILD UP which blocked the orifice.
so in your situation I recommend checking that 10mm part breather tube from end to end.
Mine was fractured just under the throttle body area. I replaced it completely and no more problems
Peter

 

a 45mm (almost 2 inches) drill bit seems a little excessive for this job ;-)

 

There should be a coarse steel wool packing held by the baffle in the valve cover. If that is missing it's easy to draw oil mist through the full load breather.

 

Thank you. When I look in the cam cover there is a plate but I am not sure if the wool packing fell out or not. Now I have an even worse problem.I tried putting foam in the cam cover under the full load breather and apparently caused too much pressure built up and blew oil from the cam covers. Pulled the foam out as oil smoke everywhere!
Looks like I will be pulling the covers to refit the gaskets. When I do I will check for the wool.
Pulled air filter out as soaked with oil. Holy cats! Stepped on it and broke tires free in 2nd! Is this what it is supposed to feel like! Real kick in the pants performance. I really can't see the motor being worn out. This is gong to make me crazy. Any ideas would really be appreciated. Thank all.
Yeah, there is a mist of oil that comes out on the cam cover.

 

Although I usually discount the arguments offered by "catch can" proponents, your situation might be best fixed that way. Google is your friend!

 

45mm is the depth outlined in the jaguar service paper.....(don't have it infromt of me to confirm) but the figure is stated officially

 

I still say your part load breather tube is fractured somewhere along its length Or indeed the orifice is blocked ie 45mm clear depth not met

interesting to see what the cause is.