Hello I hope someone might be able to help me. I have a 2007 Disco TD V6 that runs fine ordinarily but as soon as I hook up my caravan I get coolant loss from the expansion tank. I have done a pressure test and replaced the cap on the expansion tank. Coolant test for head gasket came up negative. No oil contamination and motor runs fine ordinarily. Symptoms only exist when the caravan is on. The car is approaching 240000KM. Does anyone have any ideas?

 

What country are you in, no TDV6 in North America so better off on a UK or Aus forum. Possible causes are egr cooler leaking,stuck thermostat, failing viscous fan clutch, blocked radiator, failing water pump just to name a few.

 

Coolant loss from expansion, as in boil over or do you mean the level in the tank goes down?