Hello everyone,

with the start of the new year, I fear the worst for my poor '96 XJ6, I'm pretty sure it will need a head gasket replaced.

I noticed a milky substance on the oil dipstick not too long ago, and got worried then, and two days ago I followed up with a block test and compression test, with my findings as follows.

the block test came back negative, no combustion gasses in the cooling system.

as for the compression test, starting with the cylinder closest to the front of the car, I got a reading of 170psi for the first four cylinders, a reading of 40 psi for cylinder #5, and a reading of 75psi for the last cylinder.

also, the cam cover gasket is leaking on the exhaust side at a progressively worsening rate, and with the radiator flush I did yesterday the coolant came out a green/brown mix with all kind of nasty gunk floating around.

so with a compression test reading like I got, water in the oil, oil in the water, leaks everywhere, there's almost no doubt in my mind I'll have to replace the head gasket, agreed?

This brings us to my main point, has anyone attempted or done a head gasket on an AJ16, what special tools will I need, sourcing parts, other recommended fixes while the head is off, etc, should I sell my soul rather than replace it myself? anything that would be helpful.

Another less important issue, but still on my mind, I cleaned the throttle body and now it gets stuck open while the car is on, but not while the car is off. Is this a normal thing?

any ideas are welcome and appreciated.

thanks
-pancho

 

progress thus far. the upper timing chain tensioner had me scratching my head for a moment, but I got by.

 

You should have tried steel seal first, but too late now good luck

 

I tried some liquid copper by Bar's Leaks, but it did nothing to dam up the flow of coolant into the crank case. I considered giving blue devil a shot, but I decided to just jump in.
thanks :]

 

first epic fail of 2010! the head gasket is busted up before its even in the car!

I ordered the set from Coventry West in atlanta, and the head gasket, when i opened up the packaging, had a break in it on the front timing chamber section.
failboat is now docking!

and my valve spring compressor is such garbage. good thing I am adept with an angle grinder and blow torch and hammer.

 

Well you can of course flatten it out and apply hylaseal to that area to make sure it seals.

 

I know it sucks, but remember, they didn't send you a ripped gasket on purpose. They have been around as long as we have. They are good people. Call them. They will take care of you.

 

"Another less important issue, but still on my mind, I cleaned the throttle body and now it gets stuck open while the car is on, but not while the car is off. Is this a normal thing?"

Jaguar offered a stiffer spring for this fault NBB3131AB

bob gauff

 

Oh I know the folks at coventry are fantastic, I've dealt with Pete Bond many times in the past. It's just that would be my luck.

Pete's got me another set on the way and I've got the damaged one on the way back.
They've always taken great care of me. I sourced the grand majority of parts from them while I was rebuilding my front end time and time again

and many thanks for the info about the spring. :]


paid a visit to the dealer today also to chat with a friendly tech and come to find out my local dealer doesn't do any internal engine repairs, they're more geared towards replacing parts rather than repairing them. It doesn't come as much of a suprise to me, but I just was unaware until today.

 

Well, was the old gasket breached?

 

The old gasket wasn't really breached, but it definitely was showing its age. The head was warped, and that was what was raising so much hell.

 

oh here we go. head is fresh. just waiting on the new gasket set. also got a valve spring tool that is mo betta.

 

done!

got everything put back together and assembled, runs like a dream.

a few questions though.
is there a specified break-in period for this repair?

and also, now that everything is put back together, it is exhibiting unsettling hard starting.
throttle must be applied to get her to start.
I was meticulous about the reassembly, so I'm hoping I didn't ruin anything that would cause the hard starting.
another fear was the check valve on the fuel pump, but even so, she used to start effortlessly in the mornings before I did this head job.
so I'm a little puzzled.

but overall, good results.
fresh coolant, fresh oil with lucas oil stabilizer
-new water pump
-new upper and lower radiator hoses
-new thermostat
-gaskets everywhere I could see one
-new spark plugs

:]

 

& for anyone following the story,
cured the sticky throttle issue just now,

I took the throttle body off again, removed the sensors in interest of their protection, and meticulously cleaned everything with an array of instruments ranging from shop rags to Q-tips.
Once everything was cleaned, bolted it back up, wound the spring on the throttle body counter-clockwise 360 degrees and bolted the top part back on and magic! fixed.


so. . . .
attribute this quandry to me being dumb again.

 

Sounds like you know your way around engines ! You said head was warped; normally there are limits after which head is scrap, because even if skimmed, the camshaft bores will be out of line.

 

I know, it was within factory tolerance of being machined down; if I remember right my man only shaved down half of the allowable limit.
so I could do it again if I had to!


& also the clearance for each valve only changed maybe .01mm after it was all said & done. so as far as I know, I'm good, everything else is still straight and in good order.

 

Saw this string, and looking for the procedure you used to flush the radiator. I've had my 96 XJR for many years, and I'm long overdue in flushing the radiator.

Can you provide a DIY. I've searched briefly for the drain plug on the radiator, but haven't found it yet. Pretty amazing.

Any special requirements on type of antifreeze?

I've seen a couple of comments that talk about having problems purgin all the air out afterwards.

 

the drain is in the center of the lower radiator mount bushing right side of car, lower mount (obviously) it has a slot for a screwdriver in it(at least it did before you curbed it a couple times ..) if really bad buy a new 1 before you take it off.

 

I used dex-cool gunk for my radiator. closest to the jag yellow coolant here in america

 

Actually, the same stuff as the yellow junk(Jag Coolant) is Zerex G-05 HOAT coolant, it's the same thing and it's also yellow.