I recently purchased a 4.6 hse which was sold to me with a cooling fault, the previous owner had the water pump and thermostat replaced. So when i got it i looked around it to find the thermostat in the housing (in the bottom hose) had not been replaced.So i removed the housing where the top hose fits onto,to find that there had been a thermostat fitted.I checked the manual and it stated that the thermostat was complete with the housing situated in the bottom hose area.So today i replaced the housing complete with thermostat and removed the 1 that should not be in the top hose and hey presto no more running hot,no more brick hard hoses.= one well cheap p38.