300tdi defender overheating problem

Hi all
Help needed if poss so a few weeks ago my engine overheated and blowing cold air out of the blowers. I changed the gasket again overheated in about an hr of running. Rather than mess about I bought a brand new head fitted that while I was on with it I replaced the water pump Thermostat header tank pipes and heater matrix. I have since driven over 500 miles and now the needle shoots up to red after about 3 miles heaters still blowing hot not losing any oil or coolant and neither mixing. Any suggestions I have even checked for an air lock but seems to be ok. I'm stumped I'm 220 miles from home and don't wana cook the new head if it is giving a correct reading. Thanks for any advice in advance.

Could be a short somewhere if it's not actually getting that hot, I nursed a V8 200 miles home once and it was a faulty gauge

does rad core get hot all over

jamesmartin said:

does rad core get hot all over

Click to expand...

Not sure but the RAD is also brand new well 6-8 months old

Could a leaking injector cause overheating ?
Or am I just clutching ?