air lock or worse

I posted a thread after rebuilding the top on my 300tdi. I bought the car with the head blown I have put a new head and gasket on. the car runs fine but I cant get the matrix to run hot, theres no sign of coolant leaking externally and the system doesnt appear to be over pressurising. a friend lent me a water pressure test kit so I fitted it to the exspansion tank and took it up to 15psi over an hour it lost 5psi the kits a bit old and i am unsure if its all sealed right. I have got an old 90 with a 300tdi engine fitted and noticed that when this reaches operating temperature the water in the exspansion tank gets hot but in the discovery its cold has anyone got any ideas thanks re Alistair

i assume it's the heater matrix not getting hot ?

how long are you allowing the engine to run ? - they will take an age this weather to get warm, especially at idle speeds

have you flushed the matrix to clear blockages ? - have you filled the matrix with fluid and measured how much it holds

are you sure you've got water flowing through it ? - change one of the feed hoses to clear so you can physically see what's happening

thanks for your help
on the 90 the expansion tank heats with the water on this discovery the expansion tank stays cold not sure if it should get warm or not.
The temp gauge in the cab reads between 1/4 to 1/2 after running for 30 minutes, the one hose going to the matrix warms but the other is cold it also felt like the hose going into the water pump is cold on the very bottom but hot on the sides and top the small hose which comes from the pump top to the top of the T stat housing warms well. when I drain the 90 its just a matter of filling it up with coolant and away you go are the discos known for being hard to bleed thanks

Sean said:

i assume it's the heater matrix not getting hot ?

how long are you allowing the engine to run ? - they will take an age this weather to get warm, especially at idle speeds

have you flushed the matrix to clear blockages ? - have you filled the matrix with fluid and measured how much it holds

are you sure you've got water flowing through it ? - change one of the feed hoses to clear so you can physically see what's happening

Click to expand...

Just been working on it. Started it run it for 3 minutes stop it, topped it up at the t stat plug ran it again for 3 minutes topped it up again, it only took less than a 1/4 pint in all then ran it for 1/2 an hour and its spot on heater runs perfectly and not lost a drop of water must have just had an airlock in the matrix good news for me! thanks for your help Sean

well done