I've searched the site, & the net, for instructions on cleaning the PCV system to no avail. I've disconnected the elbow hose atop the valve cover and cleaned it, as well as the 'mushroom' cap which attaches to the hose leading to the air intake at the throttle body, That portion of the spaghetti of hoses can be blown through easily and are unobstructed. But the 2 small diameter hoses going towards the ground cannot be blown through. My primary questions are:

1. Do those 2 smaller diameter hoses lead to a manifold of some sort?

2. Should those hoses allow air to pass freely?

I'm experiencing symptoms normally associated with a clogged PCV, ie, a little rough idle 'occasionally', a bit of sluggishness on acceleration, higher oil consumption than normal, bluish smoke from exhaust.

 

To my knowledge there is no PCV valve.

The breather hose connects directly to the elbow. It can get gunked up with oil and should be cleaned but it appears you have already done that

 

I can't quite visualize what you're referring to but I suspect they're part of the fuel evaporative system, not crankcase ventilation. If I'm correct then I'm not sure of you should be able to blow thru them or not. There are some check valves/control valves in that system....not really sure how it all works as I've never had to dig in and investigate.


As for crankcase ventilation don't forget that you have a metal gauze breather filter inside the cam cover....which means removing the cam cover for inspection and cleaning

Cheers
DD

 

Thanx,

The elbow which exits the cam cover splits in 2 directions;

a) one downward terminating at a 'mushroom' tip which simply sits atop a hose which leads to a connection to the intake accordian attached to the throttle body. (That one is unobstructed)

b) the second split leads to a small 2 inch 'manifold' adjacent the EGR valve. (That portion of hose cannot be blown through) I'm trying to figure out if that's the purpose of that 2 inch 'manifold. Wondering if it's meant to restrict air passage until a certain pressure threshold is achieved?

I was hoping to avoid dismantling the system, but sometime this week I'll take it all apart to determine how it all works and post results of that investigation. Thanx for the headsup on the gauze inside the cam cover. I've had a minor leak at the rear of the cover which I've been meaning to seal, so looks like now's the opportunity.

 

Ah! gotcha now I believe you are talking about the part load breather. It is a restrictor that helps maintain crankcase depression during part load operation.

There are a couple of water hoses that spur off from it. One goes to the thermostat housing and the other to the throttle body housing.

I think you are in good shape if you have cleaned the large (full load) breather and the mesh screen as Doug alluded to.

I know that after X300 production ended Jaguar came out with a mod that added a vapor separator to the breather setup that funneled excess oil back to the engine via a connection at the dipstick tube.

 

Thanx so much! You just saved me from a lot of unnecessary dismantling! I'll clean the mesh gauze on the cam cover and decarbon the EGR and see if that returns all to healthy breathing.

 

Hi Suede,

Would you post some pics for these items and locations? I cannot visualize nor am I familiar with these parts.

Thanks,

 

Not ringing any bells with me either.

I suspect our XJRs don't have the part load breather arrangement. It merits some research, though.

Cheers
DD

 

Right on the money Doug.

The XJR does not appear to have the breather adaptor arrangement. The part I believe Suede is referring to is #10 in the diagram.

Engine Breathing-3.2/4.0 Litre - Parts For XJ Series from (V)720125 to (V)812255 (X300) | Jaguar Classic Parts UK

 

Yes Allan,
You are correct. The manifold I referenced is indeed #10 in the diagram you linked. Furthur, the 'mushroom' I spoke of now appears to be a part of the retrofit you mentioned as I've just broken due to tugging too hard not knowing it was also connected to a hose from beneath (which when traced leads to exactly where you said it would - the lower dipstick). So thanx again for volunteering that tidbit as I certainly would not have figured out why my system is different from the diagrams!

And Doug, you were on the right track. Prior to removing the cam cover, I attached a piece of hose to the breather nipple on the cover and tried to blow. It was what I'd guess was 90% restricted. Pressure immediately built up in the hose and I got the nasty blast of breath in the face as soon as I removed my lips from the hose, confirming a bad blockage. Removed the cam cover and cleaned the passage. Completely cured the issues I was having. The motor has never breathed this freely since I've owned it. No more smoke out the exhaust, less intake noise, absence of pressure has completely eliminated the couple minor cam cover leaks I'd had, the periodic sluggishness disappeared, and gas mileage is up a full 3mpg on the computer. Sometimes it really is the simplest of things.

Total cost? $12 for the plastic mushroom I mangled, otherwise would have been zero. THANX so much guys!

 

Suede, where did you get this part? I could use a couple of them! I'm also going to try the blow-thru into the crankcase(s). What a great idea. The six is pushing out a lot of oil along the valve cover gasket lately.

Thank you!

 

I got mine from a local British Cars Dismantler over in West Seattle, but I got lucky that he remembered he had one sitting on the shelf that was ordered for a customer years ago and never picked up.

Jagbits stocks em, but for a kings ransom of $29 Jaguar OIL SEPARATOR BREATHER - NNB2102AA

Or if you want it from the UK it's available here: Egr Oil Seperator - NNB2102AA | Jaguar X300 - XJR | Jaguar | British Parts UK


Since it was a dealer installed upgrade via kit, it's slim pickens getting a hold of it now. For future searchers, the part is called:

Oil Seperator Breather with original part #: NNB2102AA




FYI: You can substitute one from a Land Rover Defender in a pinch. It's shaped differently, but works just the same.

 

I have a breather kit to fit to my x300, this one
Egr Oil Seperator - NNB2102AA | Jaguar X300 - XJR | Jaguar | British Parts UK
does it replace
Engine Breathing-3.2/4.0 Litre - Parts For XJ Series from (V)720125 to (V)812255 (X300) | Jaguar Heritage Parts UK
or is it instead of that kit. any explanation will help.

 

The part linked above is just the separator. At pointed out above, they were apparently somewhat fragile and prone to pulling apart, so the separator itself can be purchased.

The entire oil separator kit is JLM 20709

That kit included:

Breather-Oil Separator NNB 2102AA
Restricer - Part Load Breather NNB 3956AA
Tube - Dipstick NNB 3908AA
Hose - Oil Drain NNB 5961AA
Clamp, Hose, Worm Drive JHC 200101
Clamp, Hose, Worm Drive JHC 200401


Here is the technical bulletin that speaks to the oil separator retrofit.

 

I'm getting a lot of gunk in my driveway below the car. It is the color of a coffee with milk in it. There is no leakage around the VCG. I assume that following the steps above would resolve this?

 

https://www.jaguarforums.com/forum/x...ctions-110628/
Great thread here, very helpful!

But I have two questions.

My 96 USA VDP has apparently had the engine breathing kit installed, including the oil separator that’s about the size and shape of a walnut, as per this Technical Bulletin:
• 17-11 Throttle Difficult to Open on Cold Engine

As per the bulletin (and this thread), the entire oil separator kit is JLM 20709, and includes:
• Breather - Oil Separator NNB 2102AA
• Restrictor - Part Load Breather NNB 3956AA
• Tube - Dipstick NNB 3908AA
• Hose - Oil Drain NNB 5961AA
• Clamp. Hose, Worm Drive JHC 200101
• Clamp, Hose, Worm Drive JHC 200401

Here are my questions:

Is the ‘Breather - Oil Separator’ supposed to be empty inside?
Or should there be some kind of filter material in there?

Is the ‘Restrictor – Part Load Breather’ (that’s pushed inside the Y-shaped hose) supposed to have any check valve action, allowing air to pass only one way?
Mine passes air both ways easily.