Overheating... but not the radiator?

[badfelafel]

So hows it done without the bypass hose?

[bmcecosse]

A couple of small holes are drilled (1/8") in the rim of the thermostat to allow a little water to circulate - although even these are not necessary if the heater tap is always kept open. On the Metro they introduced a take off for the heater below the stat - and so water circulated that way. It make sthe heater much more effective - and eliminates the possibilty of bypass leak/burst!!