When I leave my 2000 4.6 for a couple of days there is a slight lowering of the bags in general, usually an inch or two.

Now and then I hear pft-pft which happens with engine running and not running, only when running it pumps itself up again and the 'pft-pft' starts again.

To take proof of the pudding I took out the timer relay and went on holiday for two weeks, today we came back and it stood on all corners exactly the way I left it.

This tells me that the bags and connections are not leaking but does that include the valveblock? Is the leveling only caused by not level parking or can O rings be leaking?

Is the heightsetting, no doubt they are not standard anymore, the cause?

Feel free to comment on this.

I would change the 5 pin relay for a four pin, that way self levelling won't start till you start the car. Mine did exactly the same as yours when I got out, obviously weight in the car has changed. When I took the engine out for a rebuild, connected battery to open the boot, again it all self adjusted. That's when I swapped to 4 pin. I know mine has no leaks in bags or valve block, sounds like the p38 poltergeist

If it doesn't drop with the timer relay removed, then you don't have any leaks in the springs or the valve block. The settling you hear when you get out of it is normal as it levels itself then goes to sleep. The timer relay wakes it up every 5-6 hours and if any corner is lower than the stored height because you are parked somewhere that isn't level, it will drop the others to the same height to keep it levelled. What happens then is that it will settle slightly so the next time it wakes up, it detects that they still don't match so will level them again. Left long enough it will be on the bumpstops.

So that is not to worry. About the 4-pin relay I've heard of and keep that in mind.

About the non-original rideheights I think some PO has put it higher on it's springs which to me is cosmetic BS when you have standard size tyres.
I already lowered it a bit via the unlocksuite, I'm still searching for Original settings and fabricating a sort of verniercaliper to measure exact beween axlecentre and wheelarch.
Thanks guys.

Best way to calibrate is to use calibration blocks. Far more accurate than any measuring you can do! These can be knocked up at home from sturdy dowel, or nylon if you want to be flash!
Have a look at the following page, about 1/4 way down for the procedure and dimensions for the blocks.
http://www.mez.co.uk/p38-eas.html

Thanks OB, I'm going to make them from wood. Need a level floor though...

Aren't you from Holland? Nothing but flatness there!

I'm in Cambridgeshire and we don't do hills here either but at 22m above sea level I think my house is higher than all of Holland!

There's also this http://www.rangerovers.net/forum/7-range-rover-mark-ii-p38/73321-eas-calibration-blocks.html and I've got the nylon rod out in the garage ready to make up a set, never have got round to cutting it up though......

Ha Ha could you please tel those expectations to our pavement stone guys to make a street level.
My street is below sealevel, the neighbourhood was made in 1978, before that is was a sort of swamp/meadow.

Two years ago they calculated that the streetlevel had sunk 20 cm and topped it up again so we are constantly moving. For that reason they don't make tarmac in neigbourhoods over here but lay brickstones. Tarmac that holds lorries needs a meter of gravel/stones as basis so don't be surprised when the street isn't level.