Heating problem I recently purchased a 6 cylinder toyota petrol motor after running for about 15-20 minutes the machine starts to run very hot ! I left the radiator cap of and dirty rusty looking water came out of the top (obviously very dirt water and need good flush out I took the themostat housing apart (no thermostat inside ?) do you think I should put one back in? also do you think that once I clean system ( flush radiator and engine block out ) my heating problem should be sloved ? No obviouse leaks , no sign of water in engine ( milky oil in sump ) fan and belt looks fine, radiator average to poor condition engine starts pretty much straight away everytime and this sounds fine. Any suggestions welcomed- thanks

SOURCE: 1966 Ford Mustang overheating

try to run the water pump without hoses, and add water in the 'in' side, if is powers out the other side, then it's fine. how is your water/coolant mix?

SOURCE: running hot

Radiator Fan Control Relay Switch. I bet your electric fan doesn't run?

SOURCE: engine overheating-----1994 Olds Cutlass Supreme 3.4 liter v/6

There seems to be an air pocket or no antifreeze in engine block. Try this method disconnect upper radiator hose and pour water directly into hose down into engine block until it full. when its filled reconnect hose and fill up radiator. as the vehicle warms up open bleeder valve on the thermostat housing and release air from system. open slowly and BE VERY CAREFUL WATER WILL BE HOT, bleed until you get a steady stream opening and cosing valve. However if all of this don't work. You may have a bad pump. Good Luck

SOURCE: 1996 Jeep cherokee, leaking coolant when cold/ hot ok.

waterpump houseing/shaft seal is on the way out hence the water/coolant, running along the block. when hot the seal does so, when cold and depressurising seal doesnt.

SOURCE: Engine overheating at high rpms

check the casting on your replacement water pump..4.0l engines require a reverse rotating water pump..may be causing your problem.