06 jeep 3.7 overheating
Jeep Guru Team my sons 06 Jeep Liberty 3.7 is
overheating. I have changed everyhing imaginable
on the coolant system to include hoses. After the
3rd thermostat i gutted one and put in. Problem
went away but threw a check engine light. In Texas
inspectiins are required and a check engine light is
an automatic fail. I had a mechanic install a new
thermostat as thinking i had done something
wrong the previous times, well same result as 18
miles in overheating. Block is hot but aft of
thermostat return hose is cold. Any suggestions
as out of ideas.
Did you purge air out of the system? Your symptoms are showing lack of circulation. When you say you changed everything what does that mean?
You need the thermostat for the engine to reach the correct operating temperature hence the codes.
Try bleeding air from system like this remove cap from overflow tank fill with antifreeze to full mark leave cap off and start vehicle and let idle you will notice level in tank start to rise this is normal once thermostat starts to open level in tank will drop add more antifreeze to full mark then put cap back on.
I changed radiator, thermostat, hoses, pressure cap, fan, sensor, fan and gan motor, relay and flushed the system. Even checked plugs and oil which showed no signs off issues. Frustrated so gutted a thernostat and problem went away...no over heating. Drove for 6 months no issue. With check engine light and required inspection had new thermostat installed and now back to over heating. This is the 4th thermostat installed and can not see why open line works without issues but with one overheats.
Look up how to purge air from a cooling system on Youtube.
Look over the thermostat housing theres 2 output metal parts that connect to rubber hoses if your jeep had complete coolant circulation those hoses should be hot as the rest of the hoses theres got to be a place where is clogged.
You have a bad head gasket. To verify you fill antifreeze reservoir to very top with water . Then watch for constant flow of air bubbles. If head gasket is bad then bubbles won’t stop coming but must keep water level to top of neck where cap goes on to observe properly.