Disco 200tdi high collant pressure

[freddie1972]

Have high pressure within the coolant system. Engine temp is showing as expected (1/2), no heat from heater. When i removed expansion cap to realese pressure loads of air came out as well as loads and loads of white foam.

Want to rule out easy things first before i go tackle an expensive head gasket route.

System is always bled by filling from radiator cap until full, toping up expansion tank whilst engine running with heater set to full.

in past twelve months have fitted new water pump, radiator, thermostate and hoses

[Tetsu0san]

When you say white foam, what do you mean? If oil and water mix, as in the case of a head gasket failure it can form a white milky sludge which can foam up too. If you take off the oil filler cap is there any white stuff on the underside? The sludge doesn't appear there on every headgasket but it's another place to check.

To be honest, what you have said already sounds like a headgasket to me. And as long as the head isn't cracked then it can be a farily straightforward job to do yourself (if you feel brave enough!).