I've replaced the water pump, reservoir cap, thermostat, thermostat housing, radiator, and bypassed the heater core since Ford decided to run heater lines to the rear roof for climate control. Not loosing coolant so I dont think its head gasket, also not seeing oil/coolant mix. Where else would I have to diagnose?
What makes this problem better or worse?
Bleeding the pressure off
How long has your 2002 Ford Explorer had this problem?
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It doesn't always overheat while idling or in traffic. Haven't taken it out on the road yet till I know it can cool itself 100% of the time. It's not a consistent symptom to pinpoint.
Mysterious overheating is often the result of ‘combustion’ entering the cooling system - there is a specific test for that.
It is not unusual for NO coolant mixed with engine oil in the presence of a failed cylinder head gasket.
It is also possible there is air still trapped in the system..
This is assuming the engine is actually over-heating and not an erroneous temperature gauge reading.
Lastly - a circulation problem typically results in NO heater output - no HOT air - - again assuming you did not bypass the FRONT havc system.. (?)
Good luck?
One last question, if it is a failed head gasket, would the symptom be present on every startup? Or not until the load was too great for it to contain pressure intermittently? I just tired to diagnose again and built pressure in the reservoir but the top radiator line was cool to the touch. And reservoir was full of fluid. Does this mean I have a failed radiator? Or air locked somewhere?
Coolant flows from bottom of engine to the top of engine - the THERMOSTAT is what’s responsible for controlling the flow rate.. However any restrictive problem would have the same effect > a cool ‘upper’ radiator hose - - this includes of course an “air lock” or combustion leakage - even a defective thermostat..
IF possible - some background / history about the vehicle may shed some light on this issue.. Perhaps the previous owner would help out there.
It doesn't always overheat while idling or in traffic. Haven't taken it out on the road yet till I know it can cool itself 100% of the time. It's not a consistent symptom to pinpoint.
Mysterious overheating is often the result of ‘combustion’ entering the cooling system - there is a specific test for that. It is not unusual for NO coolant mixed with engine oil in the presence of a failed cylinder head gasket. It is also possible there is air still trapped in the system.. This is assuming the engine is actually over-heating and not an erroneous temperature gauge reading. Lastly - a circulation problem typically results in NO heater output - no HOT air - - again assuming you did not bypass the FRONT havc system.. (?) Good luck?
One last question, if it is a failed head gasket, would the symptom be present on every startup? Or not until the load was too great for it to contain pressure intermittently? I just tired to diagnose again and built pressure in the reservoir but the top radiator line was cool to the touch. And reservoir was full of fluid. Does this mean I have a failed radiator? Or air locked somewhere?
There is no common protocol for symptoms of a failed cylinder head gasket - there are many variations.. A combustion lest ‘test’ is invaluable.
Edit to previous reply...sorry
Coolant flows from bottom of engine to the top of engine - the THERMOSTAT is what’s responsible for controlling the flow rate.. However any restrictive problem would have the same effect > a cool ‘upper’ radiator hose - - this includes of course an “air lock” or combustion leakage - even a defective thermostat.. IF possible - some background / history about the vehicle may shed some light on this issue.. Perhaps the previous owner would help out there.
Thanks for the support. I'll keep plugging away at it and keep y'all updated.
✔️