Hi all! I've been looking at getting a 2004 XJR I found on the classifieds for cheap. Since it is so cheap after all, I've been giving it a thorough look-over before deciding on buying. When I returned yesterday I thought to take off the plastic engine cover, and behold.. oil everywhere!
Looked around everywhere and couldn't find the source of the leak, but I'm guessing it has been around for a while. It seems like it sprayed from the back forward, but there was no noticeable fresh oil around any of the nearby gaskets I saw. Only places which looked recently oily were a couple wire looms and what I'm guessing is the valley hose, that short section of 1 inch ish hose near the back of the s/c.
My first question is, of course, any idea what it could be? If it's a simple gasket replacement, even something involved as pulling the s/c, I'm not too worried about the labor. Which leads me to my next question, if anyone knows what this is, could it have caused damage to the motor, gunked up the intercooler, or anything like that? I'd love to get a great deal on it if the internals haven't been ruined by whatever's been happening. Thanks for any help! (pics in a moment)

 

And I realize posts can't be edited. First time on the forums and already doubleposting...
One last thing, the car has ~150k mi if that helps diagnose.

 

Hi Nil

For a 150k mile car that doesn't look like a whole lot of oil. My first thought was that it was seepage from an engine breather connection somewhere. However, I am not all that familiar with the V8 SC engine, so see what others say.

 

I am not familiar with the 4.2 l s/c engine either but the valley hose contains water.

Maybe the oil filler cap was left off at some point (it is located towards the back of the engine) or oil was spilt on the engine when

refilling.

Is the oil filler cap on tight?

I would clean the engine by hand and if there is still a leak it may reveal itself.

 

Looks like it is time to replace the duct seals on the S/C

Its a simple and easy job to do
You done need to remove any more than the engine cover
Just remove the 4 bolts for each duct seal and wiggle them out

The seals have an inner and outer section with a press fut. This allows movement between the s/c outlet and the coolers. This seals wears over time causing the loss of boost and is seen by the oil around the seal building up over time

i replaced mine about 12 months ago and it took about and hour to do

Cheers
34by151

 

How does it look from below?

First step in determining any oil leakage is to steam clean engine frim top to bottom including the tranny.

Drive for a while and observe the engine for oil leaks. If it is leaking it will show up somewhere.

 

thanks everyone! I couldn't get a look under since it was at a dealership.

the duct seal would make sense with the way all the oil is dispersed, I just didn't see an obvious leak point, probably below somewhere. if it is the seal, why would that spray oil? isn't it just the air coming from the supercharger, or is there oil coming from somewhere before the seal?

hopefully I'll pull the trigger on the sale later today, then give the engine a nice thorough cleaning and see from there

 

The oil builds slowly over over a long time and escapes from the duct seal
So it not really a leak in the normal sense

The oil is coming from the full load breather and is normally burnt by the engine and would be sen as some blue smoke when you mash the throttle

cheers
34by151

 

I am having a similar issue, but my oil leak is coming from the outlet elbow seal, I have removed it and verified that there is oil on both sides of this seal.

Why is there oil here? Shouldn't it be air only? If the accepted answer above is correct could somebody explain to me how the full load breather accumulates oil? (Is this engine or supercharger oil?) Is this indicative of a bigger problem?

 

I am unsure how to edit my response, here is what the workshop manual says about the full-load breather:

Crankcase Ventilation
The engine is ventilated through a part-load and a full-load breather; one on each valve cover. These
flexible plastic hoses incorporate O-ring seals and quick release connectors.
The part-load breather ventilates the left-hand valve cover (B-bank) and feeds onto the throttle body
adaptor and the purge valve. This breather is connected between the oil separator in the cover and
the induction elbow.

 

That oil is blow by is from the sump and it is fed back thru the inlet system eventually clogging a lot of components.

Leaks from that seal indicate a bad seal which will let air in. I would have thought it would throw a code.

Any codes?

 

No code.

What preventive measures can I take to minimize the amount of blow by from the sump?

 

You can place a good quality oil catch can in the pipe coming out of the high load breather pipe.

It can be done without damaging the pipe so that you can, if you want to, go back to OEM. Which is what I have done.

 

jackra_1;
Would you please insert a photo of your catch can installation? Do you have to empty the catch can on occasion?

Best Regards, William

 

Baffled catch can mounted

Brass fitting into OEM connecting pipe

Overall view

 

I do empty the can every so often maybe once a year and it does catch quite a bit of oil.

The Jag is not a daily driver for me so I do not put much mileage on it maybe 3,000 a year. Updating and modifying it has been hobby for me.

I drive between MD and MA a couple of times a year so several long trips.

A quality oil catch can is imperative. It must have baffles inside and the inlet pipe inside it needs to go way down below the baffles so the mixture of water vapor and oil
has to travel back up thru the baffles to be "scrubbed" before exiting the can. I am sure you understand the way it works.

 

Thank you John! I notice the hoses to and from the catch can appear to be different diameters. Is there a functional reason for this? I've never used a catch can before but do understand the concept. I'm wondering how often I'd need to empty the can on a daily driver ( ~12 kmi / yr ). I see you have a clear tube that allows you to see the oil level.

Best Regards, William

 

The outlet of the high load breather is of a larger diameter than that of the oil catch can so I had a bit of a dilemma finding the correct diameter rubber hose as it really needs to be larger one end than the other.

I actually used a valley hose, from under the super charger, which was exactly the right size either end.

At approx 12k km a year you should only need to empty once or twice and will not be anywhere near full.

The site tube may well be the cause of a slight leak that I have causing the revs to go up and down very slightly when dawdling along at 30 mph.

Something I need to tackle...one day.

 

The above is what the elbow under the throttle body looked like on my car at about 100,000 miles.

The charge coolers were just as bad and therefore just about useless.

So spent some time cleaning all the soft carbon out.

It just so happens that I decided to try and decarbonize my 2013 Range Rover Sport inlet valves. It is a DI engine and surely has build up of HARD carbon deposits
on the inlet valves.

Have been researching this quite a bit and have ordered CRC valve cleaner and will try it on the Rover soon.

It just occurred to me that this product might well be able to dissolve the soft carbon build up in the inlet tract, including the charge coolers, of these pre DI jaguars without disassembly.

Food for thought.

I would have to be certain however that this CRC stuff would not harm the SC rotors.

 

I bought another super charger a while back and had it modified and I still have my original super charger so will try testing this CRC stuff on an exposed rotor and report back.