Shifty1962
Well-Known Member
Well both pipes are bearably hot (not red hot though) to the touch but I've not looked at the flow rates through the heater matrix.
When I fitted my new engine I flushed the heater matrix in both directions until I got clean water then I soaked the matrix in kettle descaler overnight so I'm pretty sure its not blocked. But I've got nothing to loose by checking it again.
I'm beginning to suspect the thermostat is playing up as after 15 minutes idling the top of the rad was warm to the touch with the top hose also luke warm which suggests to me that the stat is either stuck open or partially open as it should be much hotter before any coolant flows through the rad.
Got a new stat coming as soon as the postie can make it so fingers crossed.
When I fitted my new engine I flushed the heater matrix in both directions until I got clean water then I soaked the matrix in kettle descaler overnight so I'm pretty sure its not blocked. But I've got nothing to loose by checking it again.
I'm beginning to suspect the thermostat is playing up as after 15 minutes idling the top of the rad was warm to the touch with the top hose also luke warm which suggests to me that the stat is either stuck open or partially open as it should be much hotter before any coolant flows through the rad.
Got a new stat coming as soon as the postie can make it so fingers crossed.
before you go down that road, have you checked your heater water pipes. on my 300tdi with the engine at normal temp (on the gauge anyway) if i then disconnect one of the pipes from the matrix i just get a lack luster flow of tepid water so the heater is doing the best with what is has but doesn't stand much hope.
i have no idea why the water isn't red hot and pressurised
