defender 300 tdi overheating problem

defender 300 tdi. heading down the motaway at 60 mph unloaded , after 25 miles heater goes colder and temp heads in to the red. stopped and manage to remove rad and stat plugs with out scalding my self, filled with water. remove exp tank cap and half fill. start eng ,no gasses coming from exp tank. continue my jouney for the next 25 miles and repeat the process.
new water pump and stat. head gasket change last year with the head pressure tested. cooling fan was running

any help would be great
tony

hgf

i had that mate , it was the soilinoid on mine , it wasnt opening there for not letting the water circulate it only cost £15 could try that first as its cheap , hopefully that helped mate

hi, do you mean thermostat,
thanks

Think he does

yeah mate

Losing that amount of water through head gasket failure could be detectable in the exhaust, do you have white fumes/steam in the exhaust?
Water could be going into the sump so check your oil level and ensure the oil is not emulsifying.
Is the system overpressurising and blowing it out through the cap/overflow, this could be HGF or as has been suggested thermostat problems, remove it and see if that cures your problem, don't just fit a new one straight off. without a thermostat everything should run cool. heater, temp' gauge etc.

Good luck.

I had exactly that problem over the past few weeks. It turned out that it was the 'y' shaped coolant ejector pipes coming from the rad and stat housing was blocked (the one that goes to expansion bottle). That in turn caused the system to pressurize causing overheating and the head gasket to go. According to land rover in Cheltenham this is a common fault with the pipe, hence they keep a load in stock !

Good luck

I had this and it was the heater matrix that had ruptured and the water was dissappearing from inside there. Frig'd a join in the input/output pipes to get me home and ordered a new one from Paddock. Easy fix

I had this problem last year. Unfortunately it wasn't a quick fix.

After reading a LOT of forum posts, I changed waterpump, thermostat, rad, flushed the system and eventually the head gasket (inc hot pressure test). It cleared up for a couple of weeks then returned with same issue. This time I fitted a recon skimmed head (and hot tested) with new headbolts. - Been fine ever since.

If you're lucky it may just be a simple fix but you might have to go for broke and do the head again. Good luck!...