Thanks to all!
Checked the easy things. Now know it's not the fan or waterpump. Could be the fuel pump. I have a new one and will exchange.
Rattle is definately under load. Nothing heard when coasting.
Sounds to me like a rod or wristpin. I have an endoscope and will
pull the plugs and have a look at the cylinder walls.
Heat riser was one of my first checks. It's now fixed - OPEN.
Rattle is very hard like a rod or wrist pin. Sounds too loud to be something simple BUT you never know. I'll try everything and anything as I want to keep the truck original.
Seems to me like we've covered everything but if there are more ideas out there please let me have them.
Many Thanks
