Update.
Head is off, It looks like the factory installed a damaged head gasket from new.
I owned this from new and it has never had the heads off it.
Look at cylinder 2 the water has been travelling into the head for a long time. I have had a loss of coolant (just a little) for all the time I owned it, but could not find the source.
Well the head gasket finally gave up.

 

If It locked up (hydrauliced) on the starter is their any chance I damaged anything else?
like a rod?

 

I am no expert, but if it hydrolocked at idle I would think the power would not have been enough to bend a rod. You could turn each piston to dtc one a time and measure the distance from the crown to the deck- if they all match, no bent rod.

 

It did not even reach idle it was only on the starter and did not fire.
going to be doing measuring in the morning
, Dave what do you think of the condition based on the photo's

 

Looks good- pretty clean- no call outs.

I see what you mean about the gasket, there was your issue.

 

Is there an upgrade to the gaskets for newer engines, and can I use them.
I'm shopping parts now, any suggestions?

Also based on Sean B's posts I'm looking at some porting on the inlet port area.
I was going to put an AJ27 of '03 vintage in, but now I'm not sure. I'll have at least $1000 in parts on this work that was going towards a rebuilt '03 4.2

 

Well they are "the 203,000 mile head gaskets".

And apparently, routine retorquing is not possible due to the fasteners being positioned under the cams.

On the Supra Turbo, it is possible to just sneak a 6 inch long 10mm hex bit in after taking off the cam covers. Every forum member learned to do it routinely after blowing the first head gasket. Change the plugs ... torque the head bolts. No more blown head gaskets.

 

I recall reading that the 4.2 gaskets are better and can be used.
Can someone confirm that?

 

I had a veteran Chevy Mechanic with me as I unbolted the head bolts.
Using a HD 6 point 13mm 1/2" drive socket with a 24" breaker bar they took a lot of effort to unlock the bolts, The bar was flexing and when the bolts gave up there was a load crack.
even my friend said he had never seen bolts that tight.

 

That's corrosion on the threads. It would not necessarily be clamping force. Can you confirm that the bolts are directly under the cams?

I am in the engine repair manual at the moment and noticed a note that the sealing ring on the NA is steel and on the SC it is stainless steel. Of course, it is an old manual.

There are a couple of people here who prefer the 4.2 gasket as being a better gasket.

 

I can confirm, there is no way you can get a socket on the bolts without removing the cams.

Also note this engine has plastic tensioners, they were installed at 102,000 miles so have 101,000 miles on them the right bank was OK the left bank was starting to wear through, no cracks in either. The tracks for the chains are in good condition, but I'm planning on putting all new chains on.
These were 2nd generation tensioners. I will be using 3rd gen metal ones this time.
Water pump is a white impeller, should I change it?
If anyone wants photos of this stripdown PM me while it's in pieces.

 

You have an 03 AJ engine?

I doubt you've done anything to the engine off the starter.

The loud crack is correct, every AJ head I've removed does this - stretch bolts.....
I see no reason to retorque the head bolts, following Jaguar's guide to installing and torquing up, will negate this process. You'll need an 'angle' torque wrench to do this correctly.

The performance gaskets are manufactured by Cometic, not req unless a twin screw is being fitted... Cometic Gasket, Inc.

Even a less than 100% standard composite gasket from Jaguar did 200k, why not fit standard? I think the 4.2 gasket lowers compression, marginally, don't know 4sure??

The waterpump is the right one, if it feels nice and tight on the bearing and spins freely without issue or odd noises, refit? it's up to you, if money is no issue get new everything
How far do you want to go? New valves/springs/guides/seats/valve stem oil seals/chains/tensioners/gaskets/bolts + bottom end bearings, bolts, gaskets.....then you're heading towards new engine, but reflects in the time and money spent...

One picture I'd like to see is the bores, what shape are they in, can you see the original cross hatching on the walls? spray light oil in there, wipe away and get the light on them - particularly the leaky one.....

 

Worth running an M16 x 2 plug tap (if you can scrounge one) into the crankshaft to remove Loctite, particularly since the bolt that came out looked rough.

 

Morning Guys,
Sean B, it's a 98 AJ26 engine.
I am going to buy the M16x2P Tap it $31
McMaster-Carr
So when I get all the parts ordered I will post a list with costs and sources

I really wanted to put a 4.2L twin screw into this car,then I blew the head gasket, and I have to have it running (wifes car) so this work was not expected, so after talking to the wife we have decided that we will keep the XJR stock and I can fulfill my need for speed with my other toy.
It's dyno'ed at 325rwhp N/A and with a blower should see 650hp (it is a full custom motor with a bottom end good for 1000hp and 7500rpm.

 

SeanB
this is the #2 cylinder on RH

 

Cams in place covering bolts

Cams removed exposing bolts

 

Hey Roger,.....did you ever run Lucas or something of that nature through there? Looks like your valves and pistons have some deposits.

 

Get an HSS one, not carbon - without being rude are you OK using taps?
It's a big chap so hard to wring its neck but you won't thank me for that little 'click' leaving the end of a tap in the crank......
__________________

 

With the mileage on this engine I think it's got some blow by, (oil in inlet tract) so the build up is from that I think.
I'm going to wire brush the valves and try to clean it up as best as I can, but I'm not going to pull the engine and rebuild the bottom end.

 

Steve,
I appreciate the concern, I'm an English trained tool and die maker.(A long time ago)
and would be considered a master machinist, I build CNC mill turn lathes and used to be a CNC skills trainer. So no worries LOL,
I just checked the link I posted, this is the $31 tap

http://www.mcmaster.com/#8305A43

The only worry I have is how hard is the front end of the crank.