Hi All , Being new to Defenders I was easily swayed by the numerous posts on various forums along the lines of " I towed a church across Namibia without any fan whatsoever and it was absolutely fine " . So after I fitted my new 300tdi cylinder head ( to cure my " Coolant Gushing " problem ) I set off on a drive around my local area , including getting caught at a few sets of traffic lights . Not a good idea . It was clear that the engine was getting on the hot side , lets just say the heater was getting way too efficient . It was at this point I realized my temperature gauge was telling me porkies , registering 2/3rds on the white anywhere from lukewarm upwards . So I refitted the fan and what a difference . Town or country , fast or slow , even after 20 miles no overheating . I have come to the conclusion that the 300tdi is not water cooled or air cooled . It's wairter cooled ! An odd thing about it is that the newly re-cored rad only gets warm across the top , with or without the fan . I used an infra red laser thermometer on the fanned engine after a 20 mile run , I got temperatures of approx 60c from the side of the head , around 50 from the heater hoses , 47 from the top hose , 82 from the temperature sender , as for the rad it wasn't even worth pointing the thing at it . If anyone has any thoughts/opinions on this I would like to hear them .
neilly
Well-Known Member
Just for info.
Be aware that the infra red thermometers can give inaccurate reading if the surface they are trying to read is of a different gloss. iirc it is called emissivity or something like that. Plus the coverage area they measure from gets surprisingly large not far from the front of the unit.
I have tried to use them in the past and found wildly inaccurate readings going from a mirror finish steel to something like cardboard, when they actually measured the same temp.
Cheers
Be aware that the infra red thermometers can give inaccurate reading if the surface they are trying to read is of a different gloss. iirc it is called emissivity or something like that. Plus the coverage area they measure from gets surprisingly large not far from the front of the unit.
I have tried to use them in the past and found wildly inaccurate readings going from a mirror finish steel to something like cardboard, when they actually measured the same temp.
Cheers
Zed.
Well-Known Member
Recently removed the vicious fan from my '200 Discovery to access the front of the engine & change the inj pump, as we have such blisteringly hot weather here in the uk (fooknose what the Namibians get 
) I had to re-fit said fan as a precaution for towing
Obviously a previous owner or wannabeeeee mechanical genius had attempted removal at sometime in the past as there were obvious 'chisel' marks on the 'nut' but it seems they were desperately trying to tighten it (it's not a left hand thread is it? )
Rich.
) I had to re-fit said fan as a precaution for towing Obviously a previous owner or wannabeeeee mechanical genius had attempted removal at sometime in the past as there were obvious 'chisel' marks on the 'nut' but it seems they were desperately trying to tighten it
(it's not a left hand thread is it? )Rich.
