Disco 2 TD5 camshaft rotation torque

Hi all. Has anybody got any thoughts on this one? I've got a 2003 D2 TD5 (15P) which started losing water with no external leak and no oil/water mixing, no cooling system pressurising, holds pressure after shutdown, no water/steam out of the exhaust- nothing. I pulled the head and found nothing wrong- head gasket was good and the head is dead flat. I put it back together with new Elring gasket and head bolts and it's still losing water. My thought is that the head is cracked between the cooling jacket and an exhaust port. I flushed the cooling system and added a bottle of steel seal- it's still losing water!
I've got a spare head knocking around but it's got 12 thou warp across it's length. Because the head is warped, the camshaft rocks in the saddles. I haven't measured it but would guess it's in the region of 12 thou each way! If I get the head skimmed I will still be bending the camshaft when I bolt everything down. I've looked for a max camshaft break torque or rotational torque but can't find one (though I kind of know that if there is one, it would just confirm that this head is no good!)
Another used head will probably have the same problem but I won't know until I've forked out a few £hundred and a brand new head will cost more than the car's worth.
Has anybody got any experience in this area which might help me decide what to do next please? Is this why LR say don't skim heads?

Hi, I'm sure you've checked it but there is a blanking plug hidden behind the exhaust manifold which can leak and the water evapourate due to heat.
Griff

Use a coolant leak detection dye and inspect around the whole engine with UV lamp cos it can be some hairline crack in a hose or somewhere and the leak occurs only with hot engine and evaporates instantly... if it's through the exhaust that one should glow as well... e.g. something like this https://www.speeding.co.uk/uv-leak-dye--torch-kit-for-car-coolant--antifreeze-system-rld2-8960-p.asp i found a leak at the coolant rail with such product which otherwise was invisible

sierrafery said:

Use a coolant leak detection dye and inspect around the whole engine with UV lamp cos it can be some hairline crack in a hose or somewhere and the leak occurs only with hot engine and evaporates instantly... if it's through the exhaust that one should glow as well... e.g. something like this https://www.speeding.co.uk/uv-leak-dye--torch-kit-for-car-coolant--antifreeze-system-rld2-8960-p.asp i found a leak at the coolant rail with such product which otherwise was invisible

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Yep- I already used a UV dye. The only thing it came up with was a very feint glow around the rim of the tailpipe which kind of backed up my theory of a crack between the coolant jacket and exhaust port. Also, OAT tends to leave a pink stain even on small, evaporating leaks and I don't have any indications of that either. The leak rate seems to vary but it's been as much as 1 litre in 20 miles and the next 20 mile trip it loses nothing. I'm thinking that the head needs to get hot enough for a hairline crack to open up. It's difficult to believe that there are no other signs.

Landmark2 said:

Hi, I'm sure you've checked it but there is a blanking plug hidden behind the exhaust manifold which can leak and the water evapourate due to heat.
Griff

Click to expand...

Yes mate. I've had the joy of changing one of them before so that was early on my list of things to look at.

.......when I said in my original post that another used head will probably have the same problem, I didn't mean cracked. I meant it would probably be warped and therefore the camshaft placed under bending loads. LR say the head is scrap if it has more than 4 thou warp, though plenty seem to have got away with skimming it. How much can you get away with though?