Running hot at 15 psi

[Vern]

Took the other halfs Disco away last week for the first time, and whilst towing the camper it was getting very hot on slight inclines. This was happening when it was at 14-15psi (300tdi), just cruising under light load, particulalry bad on the Doom Hwy (hume), back off to around 10-12psi and it would cool down quickly, or knock it back a gear and it would cool of aswell, it was just seaming to happen when at around 14-15psi.

History of the motor is its only done around 40,000k, viscous fan was done around 60,000k ago. Motor runs fine around town and everywhere else, just under load with the trailer on it gets hot at that particular boost.

Radiator has never been looked at though.

Any ideas? :(

[PhilipA]

Radiator has never been looked at though
Time to look. generally overheating at highway speed is blocked rad as first suspect.
A standard cooling system should be able to low range at 50c.
I went up Mt Ousley at Wollongong yesterday ( for those who do not know it is very steep and long) in about 28-30 c, towing my 600Kg camper at 80KMH, and the gauge did not move one mm. That is a 3.9 V8 but LR design their cars whether V8 or diesel to do that.
Regards Philip A

[Vern]

This is only doing it when towing, doesn't even look like getting hot when not towing, and it is also when around 100k/h when boost is at 15psi. Low range its fine aswell, unladen its fine, just towing its not

[PAT303]

My defender did the same thing six months ago,rad was 50% blocked.Took the tanks off,rodded it,all good now. Pat

[Vern]

Yeah thats what i think is wrong, oh well better price up a newy:)

[Tank]

Yeah thats what i think is wrong, oh well better price up a newy:)
Just wondering if the boost compensator might be acting up, Regards Frank.

[DirtyDawg]

Check your thermostat..mine was seized open doing the same as yours...the gauge was moving a bit on hot days only...everything else cooling was new..did the thermo test and realized it was seized open:( changed the thermostat..back to normal again.