ok where do i start. I thought my engine was a little tired and was making a bad old steam engine noise when idle so thought new cam and do the seals and oil pump at the same time. So new cam in . lifters and valve train was inspected and was ok, with no play that would consider a new rack of rockers. Big ends wiggled with molegrips and no play.
Now the engine fired up fine and ran at 2000 revs for a couple of minutes and alls fine. As soon as it was hot i got the same steam engine noise from the car. Its not the cam or the lifters as its fine when cold and i've inspected the rockers. It does sound like a bad lifter and it disappears under load and over 2000 revs. It does not use any water and is not under pressure. Its a late 2000 4.0 thor engine.
Ive read several threads on this very subject and most have changed cam shaft and lifters to get the same noise when hot. Its also very common in late discos with the v8 in.
I read a good article from a workshop in the states (lost the ref to site) and it says that the noise is piston slap as the skirts are worn to more than 10 thou will produce this sound.
This would seam to be the answer. I had the same noise before and after cam fitting, but sounds like a lifter not working and is anoying for those of us who like a nice silent smooth engine.
If i took the heads off again i would see if a liner had slipped.
So what next. Do i just put up with it or change the pistons. I already have a new set of big end bearings and bolts.
Its me doing the work so no costly grease monkey bills.
Its a hard one as i dont think the car is going to last more than a couple more years tops. I think i will do a compression test and see what it throws up. It did use oil before the cam replacement, but put this down to the main seal at the front leaking. This has been replaced.
Love the car but it seams as though im constantly under the bonnet or underneath the thing. Wife wants a newer rangie but it sounds like these are just as bad.
I shall try and find the article again and post the link up
The reason why i'm writing this that no one has come up with loose piston theory before on this subject of tappets, cams , liners etc and is another spanner in the works for those who dont have a clue

Found it:
JE Robison Service — the blog: The last word on Land Rover liner failures - I hope!
Interesting reading and over the pond as well.
Please dont tell me to put in top hat liners and new pistons thats 2k in parts alone and a whole lot of time. Wonder how he expanded those skirts on pistons ?

Did you post asking for advice before tearing the engine down? Because the noise you describe is classic slipped liner - I would have thought you would have got several replies to this effect.

Thats the reason why i posted. Did you read the article from accross the pond. Later blocks had a step in it so would not slip down and the noise he describes for piston slap is what i have. Already had the heads off and no step in liners/top of block
Thats the whole reason for the article. Its not always a slipped liner. No one has ever looked into piston slap on this forum as i'm aware . Im not going to strip it down this side of christmas as its not a liner so can wait.

Thats a really interesting article I have my block out at the moment and have a cracked liner looks like a ring has broken and gouged alump out of the liner causing a crack at the top having read that article will be inspecting the block round the head bolt holes was having a new liner fitted looks like top hat only thanks for posting thar article

Willos said:

Thats the reason why i posted. Did you read the article from accross the pond. Later blocks had a step in it so would not slip down and the noise he describes for piston slap is what i have. Already had the heads off and no step in liners/top of block
Thats the whole reason for the article. Its not always a slipped liner. No one has ever looked into piston slap on this forum as i'm aware . Im not going to strip it down this side of christmas as its not a liner so can wait.

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I was under the impression that it can be quite difficult to spot a slipped liner visually? I suppose top hats would be the best solution long term.

Block was never strengthened for over bore. Liners are too thin and have no support. Cracking most certainly caused by hydraulicing. Bolts being fitted into block without making sure there was no oil/water in the bolt holes. Or by some idiot over lubing bolts before fitting. Lower cylinder is splash lubricated biggest cause of wear in piston skirts is lack of oil changes. The carbon particles in the old oil make it like lapping compound. It will wear anything it touches in time.