Opened bleeder valve on charger 2.7. Only vapor comes out. Bad pump or thermostat?

You might have air lock in heater matrix when bleeding it put heat on full an nd let it get to temperature and bleed it then ..I had a Volvo f12 globetrotter that would overheat coming up Mont blanc at minus 20 outside temperature it was radiater changed perfect after

Head is probably warped they are very very bad about that especially if they have been over heated much one thing i do have to ask did you open bleeder valves when adding coolant becouse if not it gets air traped in them badly and they keep overheating

i would take a close look at the water pump
if the water isnt moving through the system it basically becomes a kettle
thats why steam comes out of the bleed nipple

Sounds like you still have air in the system. What engine do you have? There should be a bleeder valve on a housing on the engine where the upper hose attaches.

Fill the reservoir with coolant and open the bleeder valve. Start the engine and let idle. Close the bleeder when a steady stream of coolant comes out. Continue to let the engine idle while periodically opening the bleeder valve to check for air. Keep the coolant level full while the engine is running. Once the fans come on the air should be bled out and the radiator cap can be reinstalled. Snapping the throttle a couple of times will also help push air out of the cooling system.

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Okay, it may be due to overheating, that may be the noise you heard, lets hope. first allow engine to cool, open radiator cap or the resivoir cap, which ever is the fill, remove the bleeder at top hose and fill radiator slowly until coolant comes out bleeder.

note if water pump was replaced due to leaking and engine was overheated at that time then it may be a good idea to replace the thermostat .
after filling is done start engine and allow it to run. watch temperature if temp start to climb past half way shut engine down and let sit for 5min. then restart and check level, in res do not open cap . feel air from fan and see if it is getting hot, this may take up to a half hour but do not drive,

A few questions, does this jeep have an electric fan?
when you heard the knocking was engine temp hot?
If you start jeep cold does engine knock?
Did this jeep get a new thermostat with waterpump job?
did it overheat when pump went bad and why did water pump get replaced?

sorry for all the questions ,just trying to get all the info to help you .

Alot of time you have to bleed the cooling system after changing a thermostat it gets an air pocket in it look for a bleeder valve near or on the thermastat housing if so bleed it to get the air out.check the radiator and make sure its full because if you filled it up after changing the thermastat once the thermastat opened after the engine ran awhile well the cooling system needs refilled.

Probly not. Unless the pump is run by it's own belt which broke. Usually , a pump is good till it starts leaking all over the place.
Please explain overheating problem more. Is it while you are driving , or when you are stoped in trafic. Does it heat up and overheat very quickly after you start the car. Is it really overheating , or is your guage just showing overheat.

There a bleeder valve running alone the front on motor on a tube, with engine off open bleeder valve till no more air come's out, add coolant while it's open, then close, and recheck.

I have a 1985 Jetta diesel. What I did since the car has no way of bleeding the air out of the system via bleeder screw I parked the car on a slight incline leaving the tank for the fluid at a higher level. I ran the car until the thermostat opened (The thermostat is on the bottom of my engine) I kept topping off the antifreeze. I also kept a jug of anti freeze and water in my car for the next few day. Whenever I got done driving the car and the car cooled off I would check it to see if I needed to top it off. I finally got the air out of it. You could call the vw dealer to see if there is a bleeder on the engine, if so open the bleeder and fill until antifreeze/water comes out, then close the bleeder and top it off to the full level. Just to be safe check the level after you drive the car. Air can still get trapped.

look for bleeder screw on thermostat housing or front middle of intake manifold area.open bleeder while vehicle running bleed air out.