Just done the head gaskets on my 99 XKR. When I started taking the engine apart i took the throttle body off and in the elbow the supercharger i found a big puddle of oil, is this normal or is this caused by the failure of the heads or something else.

Cheers
Stu

 

Here's the inlet elbow to the supercharger.


Here it is out of the car.




And the inside of the supercharger.


Is this normal?

 

Some oil isn't a problem, especially when you use the power of your engine now and then you get some oil thru from the engine breather.

If however you would have an oil flow from the engine breather point inside the intake tube downwards to the airlifter it would be too much.

 

Whats the airlifter? is it safe for me pull off the breather pipes going to the elbow and throttle, and plug them and then run the engine on idle to see if it stops the buring oil and stop the smoke coming out of the exhaust? I have done a compression test on the engine and they all round the 120psi mark.

Forgot to mention in the first thread that the engine is back togther and it runs fine but the exhuasts are smoking a bit, it gets worse the higher the revs.

 

Airfilter I meant of course.

Iirc the compression should be arround the 140 psi mark, not sure what it means if all are about 120 psi though.

You could disconnect the engine breather (and close it on the intake, but leave open on teh engine), and then rev the engine to check what comes out of the engine. If it is already very cloudy (oily) then that is not a good sign, and if you also see the oil flowing to the airfilter as described, then these could be signs of nikasil issues (so worn cylinder linings).

 

Cheers i'll try running the engine with breather disconnected and see what happens. I really hope its not linings.

 

I think he means airFILTer.
I've always got oil in the intake tract when I take the TB off. I think with my rig it's just the age (145k miles) associated blow-by pushing an oil mist into the breathers. It condenses when it hits the cold intake elbow. He's right, when you punch it most of the oil will clear out but of course that creates more blow-by. My engine breather test still creates the proper suction so I just keep it full of oil and don't worry about it.

My car used about 2-1/2 qt in the 5500 miles of the last oil change and I figure most of it is going this way. I'm told these cars normally use a quart in about 2500. I've thought about making a swirl pot for the breathers to trap the oil before it gets to the intake. Small planes with the old oil bath vacuum pumps had those to get the oil back to the crank case. For this application it seems more of a curiosity so that'll be something I get around to. Some would say that oil is just good intake valve lube. P-)

Mike

 

Higher rpm smoking is usually related to the condition of the cylinders and pistons. The oil coming from the elbows is blow by. The compression on the 4.0 XKR should be 180 psi (+/- 10%). If you are not ready to refurbish the engine, I'd switch to a straight weight motor oil of a higher viscosity, like a SAE40. You will find this in the diesel oil grades like a bulk store or a truck stop might have. It will not hurt your engine since diesel oils have more friction inhibitors. The higher viscosity will burn a lot slower. The EPA might not be too happy with you, but bottom line is you will pollute less. The XKR takes 2 gallons of motor oil.

You will smoke more and use a lot more oil if a mulitgrade is used in comparison. There are products out there like Ring Seal and Motor Honey as a temporary solution to add to the crankcase oil.

If you decide to re-ring the engine, do not HONE the cylinders EXCEPT to repair scoring. You cannot hone NICASIL or CHROME bores anyway. I have done much research in this regard. It will destroy the rings, and you will continue to burn oil. New rings today need a perfectly round polished surface to ride on. They use a honing process to finish the rings. You CAN polish the cyl bores with oily emery cloth and a 20,000 rpm rotary tool. This has been known to increase HP by reducing friction on engines with "cast iron bores" only. You will soon know which kind of bore you have.

If you detect a ridge at the top of any cylinder greater than .005", a rebore or a re-sleve will be necessary.

Good Luck

 

Just to complemnt, a 99 XKR should have a compression of about 140 psi, at least according to jaguar documentation.

 

Yeah im going to go with 140psi. I am using 10 40w part synthetic oil from my local auto shop. The thing is before the head gasket went there was very little to no oil coming out of the exhaust. Maybe the oil that was in the engine before was much thicker or had an additive.

 

Avos,
Interestingly, I haven't run across that particular doc where it cites 140 psi. I have a 2001 XKR. It actually has 180+ psi compression after 78,200 miles. The Jag docs I read on the 4.0 say the same + or - 10%, and it doesn't distinguish between the years or between the SC and the NA engines which are 9:1 vs 11:1 compression ratios. This would indicate to me anyway the blower is actually working at starter cranking speeds. I would expect the lower psi you speak of to be with the blower belt off maybe? Next time I pull the plugs, I'll try to verify this.

 

I got the info from TSB303_55, here is a quote from it:
1. Switch the ignition 'ON' and wait 10 seconds.
2. Depress the throttle pedal to the floor. (This will enable fuel cut off ).
3. Crank the engine over until the maximum reading is achieved on the gauge (approx. 8 seconds).

AJ26
97 MY 4.0l 160lb/in2.
98 MY 3.2l 170lb/in2.
98 MY 4.0l 165lb/in2.
98/99 MY 4.0l SC 140lb/in2
Note: Cylinder to cylinder variation
should be no more than 10%
These figures are not pass or fail
but typical values to expect.

 

thats not bad, you should be the normally asp intakes. they hold a good quart in the bottom and another reason why jaguar uses crossover intake ports that do not sit down low inside the intake manifold. it would eventually suck up oil.