Zd30 common rail overheating

[mudski]

An airlock can cause overheating.

Have you burped the air out of the system. Park the vehicle with the nose slightly up hill. When the engine is cool, take off the radiator cap and tape a half 1.25 l plastic soft drink bottle to the radiator neck. Take the overflow hose off at the overflow bottle and tape it up to the bottle, or block it so water doesn't flow out.

Turn the car on and run it until all the air comes out the neck. Squeeze the hoses to help move any air. On my petrol engine there is an air bleeding screw near the thermostat. I don't know if the ZD has one or not.

You don't need to burp the cooling system on those Craig. They are a self burping system in a nut shell.