Depending on the year of your diesel, the little hose that goes from the radiator to the coolant tank can be an issue.
The later diesels had a pipe that followed the wing and went straight to the coolant tank. Earlier diesels had a pipe that dropped down below the battery and raised back upto the coolant tank.
I had the earlier pipe and refitted it with a quality pipe like the later models. No problems with bleeding and as datatek says, front end of the car raised helps a lot
Check=
The water pump,
Thermostat and fan have to be in good order.
Grab the fan and check for any movement at all apart from rotation.
It should roar on cold start up and release after a few minutes.
If it spins freely and no resistance when the engine cold it's dead!
If it doesn't stop roaring after a quick drive and engine warm not hot it runs the risk of breaking up at engine speed.
Check the radiator for any signs of cracking on the plastic top and bottom,
check for any leaks or crystallized coolant, blue, green or pink around the joints to the plastic top and bottom.
Check the body of the radiator for debris which stops airflow.
Finally, if all checks out get a sniff kit from the internet that simply checks for exhaust gasses in the coolant. If it changes colour as per instructions then you'll definitely know there is a an issue somewhere.
Craked head,
Cracked liner or busted gasket.

p38DH said:

I know the bleed pipe is clear I checked so thanks for the info .
Hopefully it will be sorted I've order a thermostat, water pump new radiator and new header tank
If it is the head ill have to learn on the job

Click to expand...

Don't order anything until you've checked it over. It could be money for nothing

Something like this, it's the least you can spend to verify the coolant and gasses that may be present.

He just happens to be working on a land-rover

Mark Piercy said:

Depending on the year of your diesel, the little hose that goes from the radiator to the coolant tank can be an issue.
The later diesels had a pipe that followed the wing and went straight to the coolant tank. Earlier diesels had a pipe that dropped down below the battery and raised back upto the coolant tank.
I had the earlier pipe and refitted it with a quality pipe like the later models. No problems with bleeding and as datatek says, front end of the car raised helps a lot
Check=
The water pump,
Thermostat and fan have to be in good order.
Grab the fan and check for any movement at all apart from rotation.
It should roar on cold start up and release after a few minutes.
If it spins freely and no resistance when the engine cold it's dead!
If it doesn't stop roaring after a quick drive and engine warm not hot it runs the risk of breaking up at engine speed.
Check the radiator for any signs of cracking on the plastic top and bottom,
check for any leaks or crystallized coolant, blue, green or pink around the joints to the plastic top and bottom.
Check the body of the radiator for debris which stops airflow.
Finally, if all checks out get a sniff kit from the internet that simply checks for exhaust gasses in the coolant. If it changes colour as per instructions then you'll definitely know there is a an issue somewhere.
Craked head,
Cracked liner or busted gasket.

Click to expand...

Sorry, you missed one, if you can stop the fan with a tightly rolled newspaper when the engine is hot, that also means it's fecked and is the most common problem.

Datatek said:

Check the viscous fan is OK, it's a major cause of overheating.
Check any new thermostat in a pan full of boiling water before fitting it, there are a lot of dodgy ones on the market, also it should have a bleed hole which should be located at the top.

Click to expand...

Thanks

Datatek said:

Sorry, you missed one, if you can stop the fan with a tightly rolled newspaper when the engine is hot, that also means it's fecked and is the most common problem.

Click to expand...

Quite rightly added sir

My advice is just hang around here with us for a bit.
Maybe cross reference with a copy of RAVE and ask if you feel you don’t fully understand something.
Once you get your head around it there’s not much you won’t be able to diy with mostly basic tools. Won’t be long a head rebuild won’t be a worry how much a willing garage is gonna fleece you and cock it up, just a case of which weekends will not be raining enough for you to finally get round to doing it.
Sadly many of the P38 artisans are no longer with us, but much of their expertise still exists in the historical threads/searchbar and we are lucky enough a few of them are still with us today aswell as people like me that had the opportunity to pick their brains and learn directly from scratch.