Resiviour tank boiling andnover filling from top . Thermostat changed
If water pump operating properly I would check for blown head gasket.
No water in oil
Will not always have water in oil with a blown head gasket.
Verify that the reservoir pressure relief cap is holding 14 pounds of pressure or try a new cap. Was there a leak in the system? And did you put stop leak in the radiator? If so,maybe the radiator is partially clogged. Is the radiator fan working properly?
A blown head gasket could be leaking exhaust gases into the water jacket causing extra pressure to build up. Evidence would be bubbles in the water and exhaust gases.
There's is no leak in the system the antifreeze is only leaving from the resiviour cap which has been changed so has the thermostat.. could it be the thermostat sensor
Ok. IMO it sure sounds like a head gasket issue. Head gaskets not always leak or loose coolant or let coolant get into your oil. Sometimes it's pressure from the cylinder leaking into the cooling system causing the system to boil over. So if water pump is pumping properly, thermostat installed correctly and proper temp range, hoses not collapsing, coolant level correct, rad/res cap proper psi, radiator flowing freely then we are right back to the possibility of a blown head gasket. Do a compression check to find out.
Check the pressure at the cap. And check for exhaust gases. Is the gauge in the normal range? Or is it reading overheating? What is the antifreeze/coolant ratio? When was the antifreeze/coolant last checked?
The gauge is reading normal.. no exhaust gasses
If the temperture gauge is reading correctly, the pressure cap capacity and/or ratio of distilled water to antifreeze/coolant might be the problem. Pressure should be up to but not exceeding the 14 pounds of pressure rating of the cap. Coolant/antifreeze to distilled water ratio should be in 50:50 ratio range..
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