water topup

im not trying to take short cuts but it was local land rover dealer who advised me to try it first he said it could be porous block and this would cure it and its only over heated 1 time yesturday and when i got home topped it up and let it run to temp it didnt go passed half way on temp seemed fine (apart from this bubbling) i took of the little pipe of header tank connected hose and flushed it through i need to no how much water it takes to fill roughly

i also need to no where thermostat is so i can check that and how do i check the water pump is working im sorry to be a pain but id like to rule out everything before i break down and cry and give in to head gasket

Thermostat is located directly above the bottom hose outlet on the Rad.-it's in a sealed ball shape plastic housing that looks like a Fennel bulb.
If the water pump is on the way out or gone, water will leak along the shaft which the pulley is mounted. Internally, there is only an impellor mounted onto the end of the shaft which runs in a chamber. Usually the only thig that goes is the bearing/seal.

right been round all hoses and someone had taped the overflow pipe on header tank up undone it run engine for 20 min been out for a good drive no overheating water level fine no over pressuring not sure if it has cured problem because id like to no why it was taped up could it be masking another prob ???????????

sorry to say it sounds like cracked block commonly known as porous block. The blocks dont go porous as some people think but the block develops cracks around the liners. Its almost impossible to find them but if youve checked compression and its using water on v8's it is usually this. We've done 3 so far and believe me we tried everything from new cooling system to block sealer! (last resort in desperation). How is the temp gauge reading? You usually get some temp variation as a pointer but they can run fine as yours seems to be doing just using water with no overheating.

Sorry just read posts properly! I doubt the taping up would be the cause of water loss but see how you go with water loss, i really hope it is something daft. I found a place who supplied top hat lined blocks for £875 plus vat but obviously youl have to do a full rebuild yourself, ill find the website address just in case.

The reason for the tape i suspect is due to the pressure in your system forcing water out of the overflow pipe. The previous owner probably spotted this and tried to stop it with tape but the pressure has to go somewhere. It can find its way into the combustion chamber through the gasket or out through the rad cap. i suspect the excssive pressure is the root of the problem.