you looked at it Timing out of adjustment can cause overheating.
the thermostat will be under the THERMOSTAT HOUSING, which is where the TOP radiator hose fits on ie(radiator to thermostat housing) this keeps the engine at an OPTIMUM temperature BUT can be A cause of OVERHEATING IF malfunctioning
It could be the radiator is clogged. The thermostat could be bad (prevents the coolant from circulating from radiator to engine block)
clogged radiator or bad water pump
A bad water pump or thermostat can cause an engine to overheat. A plugged (clogged) radiator or heater core may also cause an engine to overheat.
A faulty thermostat or possibly missing thermostat. The thermostat controls the amount of coolant flowing from the water pump through the engine and then to the radiator. If it sticks open it will not let the engine heat up to design temperatures.
You have a blown head gasket.
low coolant ,froze thermostat ,leaks in hoses ,radiator
timing is wrong, coolant leak, bad radiator or thermostat, head gasket....
Your radiator fan. It may have a thermostat on it that lets it turn on and off to cool the water in the radiator when needed. They can be quite noisy.
Ingeneral, the fan will run only if the temperature of the radiator is above the normal range. If the fan is running, then the radiator must be over temp unless the radiator fan thermostat or it's relay is defective. If the radiator truly is over temp then you have a larger over-heating problem You state the thermostat was replaced. if you replaced the fan thermostat then either the radiator really is over temp and it is doing what it should, or there is a problem with the thermostat-fan relay or switch. If you replaced the engine thermostat that controls the flow of coolent between the engine and the radiator, then that probably wasn't your problem and you should look elsewhere for an overheating cause. I would start by determining if the engine actually is overheating or not. If it is, I would look for coolent system problems like the engine thermostat (if you didn't replace it already), water pump, leaks, scale build up in the radiator, or blockages in the system. If the engine isn't overheating then I would consentrate on the fan, fan thermostat and relays.
radiator hose needs replacing. use and heat will cause hose to collapse when worn out
Running your engine without a thermostat will cause it to run hot. An engine will run cooler initially without a thermostat. After that IT WILL NOT! Why you ask? Again, physics. An engine running without the restriction of the thermostat in the system (remember, even when it's wide open there's still some restriction in the system caused by the thermostat's small opening) will not keep the coolant in the radiator long enough for the radiator to 'radiate' the heat. That is, the coolant must stay in the radiator for a certain amount of time to dissipate some of the heat it has absorbed from being in the engine block. The coolant is in the block. It's hot. It moves to the radiator and gets rid of some of the heat. If it moves through the radiator too FAST, without the restriction of the thermostat body, it won't get rid of as much heat. Basic Thermodynamics at play.