Ok....

Before I dive into pulling the cylinder head off........

Gonna ask you fine mechanics thus.

Got the kitty running.

Misfiring.

Blue smoke.

Couple of the plugs are wet.

Head gasket blown???

 

Blue smoke means there is oil burning. Which is what I am guessing is on the plug(s). Which plugs are wet? If you clean the plugs up and start the car how does it run?

The first thing I would do is go down to the auto store and loan a compression tester. If you find a cylinder with low compression you can put a bit of atf fluid in there and see if it brings the compression up. If you find a cyl. with low compression and adding atf to it does not help then most likely your rings are fine and the problem is elsewhere. If fluid does help compression then worn piston rings may be the problem. Now because you already seem to have beaucoup oil leaking in, maybe enough to act the same way as the atf would you might get a bit of a misleading result. I would ensure I did a proper leakdown test before I concluded it was piston rings though. If all compression numbers are good and similar you might still have a gasket leak but I would turn to valve train, it is moot though because either way that head is comming off.

Assume your piston rings are good and your head gasket is good then you might have a severly worn valve guide that is leaking oil down into the cyclinder. So much so that it is coating the plug and not allowing it to fire.

With that said the only oil passages that pass through the head gasket in the motor are in the front and back of the head.
One of the most notorious passages to leakage due to a bad head gasket is the front right by the upper chain tensioner. Jaguar released a revised head gasket with an o-ring to fix this bugger. I have not heard of it making it's way into the engine and rather leaks out the side of the engine; probably because it is farther away from cylinders and like most things will choose the path of least resistance.

So my guess is your leak is arising from a problem in the valve train. It could be the head gasket and it could be bad rings. I would guess the odds of two piston ring sets failing at the same time to be less than two valves wearing. The exhaust valves are constantly submerged in oil, even with the motor off and early cars did not have valve guide seals on the exhaust side creating a nice environment for oil leakage through worn guides.

Headgasket failure leading to leaked oil seems rare to me as well since most of the passages are a fair distance from the cyclinders and oil would probably find it's way into the coolant too if it was to make it's way into the cyclinder.

I use the words probably and may a lot because I am by no means a Jaguar expert or even an expert mechanic. I speak from the fairly little knowledge I have. I have done a head gasket and valve job on this engine before though.

 

Ok....

Well....the wetness seemed to be clear to greyish...

it didnt look like oil..

the plugs were black though.

I work at autozone....so I'll get a comp tester at work.

 

Hmm might be water then. You say the smoke is blue though which is characteristic of oil. However if I have learned anything it is that everything can have an anomoly. Does the smoke smell sweeter and dissipate fairly quickly? Oil smoke will smell like burning oil and is very unpleasant.

Sounds like water if the plugs are coated in clear liquid, oil is pretty easy to tell on them imo. Which is probably a good thing. Water probably means just a new head gasket and maybe minor head work. Lot less hassle than valves or rings.

Id still do a compression test as well as look for bubbling and gurgling in the coolant reservoir.

 

None the less...

After I do a compression test....i'll still probably pull the head.

I dont need to take the cams out correct??

Just take the cam gears off.

 

No you don't need to remove the cams. Just the sprockets and don't forget lots of rags.

Also if your car is or will be a daily: before you remove the head you might do yourself the favor and measure valve clearances. Removing the cam shafts is easy once the head is off and then you can note the valve spacer sizes you have. If you measure valves and find one is slightly loose or they all are slightly loose sometimes the spacers get mushroomed by the valve and all you must do is flip the spacer over.

Having the spacer sizes for each valve will allow you to order the correct size spacer without having to take the cams off first, thus avoiding bringing your car out of commission for days.

 

I have a machine shop here close that can do all of that.

Resurface.
Tri-angle valve job....

whole works for $260.