indicated over temp

got a defender 90 with a 200tdi conversion. went up to the dales from reading and on the way back swapped drivers halfway. up until that point no problems and then the transmission tunnel got very hot. kept an eye on engine temp and found nothing unusual. 30 miles later and the needle is past red and the fuse that runs the radio has gone.

checked the oil and coolant levels which are fine and the engine doesnt seem hot. transmission tunnel still feels hot. changed the fuse and the needle seemed to stay in red for a while.

i left it to cool and the engine started again no problem. the fan runs when the engine is running and when i limped it off the hard shoulder the temp stayed fairly normal.

i have a feeling its the thermostat but i cant help wondereing why the transmission tunnel got so hot

any help would be great

the transmission will get hot..theres a fookin great gearbox under there..

sounds more like an earthing problem somewhere thats blown ya fuse and giving a false reading on the guage.

get the enjin temp to where you think theres a problem and connect a seperate earth to the guage and see if the guage alters

also check the temp sender wire on the side of the water pump

ok thanks for your response. im not a total retard i realise theres a gear box under there but in all the motorway journeys ive ever done its never got that hot. the reason for that was low gear box oil ive since found out.
thermostat was stuck and im waiting on a compression test to find out if my heads warped.
as for the earthing ill check it anyway just to make sure even tho ive found the thermostat problem

I very much doubt it's an earthing problem as suggested because the gauge earths via the sensor into the block - it would just go off the scale if you put that wire to deck – if it was the voltage regulator that feeds the gauges the others would be showing strange readings too. It did what it was meant to do, show the engine to be hot when your stat stuck.

The transmission tunnel will get hot for several reasons, there are two gearboxes down there, both get hot, and the exhaust runs down one side of it, heat will rise into the tunnel area. The engine heat that gets blown over the engine to the bulkhead will get blown along there. If you suspect the gearbox is getting too hot get under the Landy and touch it, it will be hot but you should be able to put your hand on it comfortably.