Defender loss of power and over-heating

Hi All
Our '07 Defender suddenly lost power today and the temp gauge rocketed up into the red. Once it had cooled a bit I poured 1.5 litres of water into the cooling system and it ran fine for the rest of the journey (5 miles). It first lost power going up hill behind a lorry. It had been fine before that and we did 250 trouble free miles in it yesterday. We're on holiday in Cornwall at the moment. By the way the Landy has an auto box conversion. Any advice gratefully received, but I'm not technically minded so keep it simple!!
Cheers
Rich

First thing I'd check would be the radiator/oil cooler.

I dunno about the '07 engine cooling systems as such, but my Disco 300Tdi had exactly the same symptoms once when pulling a caravan .. turned out to be a complete loss of fins on the engine side of the radiator. The rad also includes the oil cooler on a 300Tdi engine, so when the cooling system loses out, the oil heats up and the engine suffers a double whammy, no cool water, no cool oil (cool being relative!) ....

During normal running it was OK, pretty soon after heavy loading, like towing or steady drags up hills, it'd heat up very quickly .... It had two head skims and gasket changes with no change of symptoms before we found the issue with the rad ... New rad, completely fixed!

If it's a puma - 2.4tdi transit engine, once they get warm there is a sensor on the back of the head that cuts the ecu so it will only idle. I am half way through a head gasket replacement dud to same issue

Mulcaster1 said:

If it's a puma - 2.4tdi transit engine, once they get warm there is a sensor on the back of the head that cuts the ecu so it will only idle. I am half way through a head gasket replacement dud to same issue

Click to expand...

Didn't know that ..

Could still be same issue then, just being dealt with by the sensor! But yeah, it is probably as likely to be head gasket, that's what they originally thought on mine.

I thought I had run out of diesel! But it's a safety issue - I have done a thread on here - Puma advice. There is a picture of the gasket also to be seen

Did 45 miles it today and it ran fine. Fingers crossed for the rest of the week. Will get it checked when I get home.