I have a 2000 jeep grand cherokee 8 cyclinder i recently replaced the radiator and water pump and thermostat and now every couple of weeks the temp gage goes up to 260 and the truck is still runing fine i had to let air out of system and it runs fine for a couple of more weeks and repeats. My heat doesnt work because of the air doors and since replacing the radiator you can hear water gurgling in the heater core any suggestions???

Would seem as though the thermostat is stuck closed

Cold radiator & no pressure !!!

the water pump may be faulty or the radiator could be blocked.....cheers.

Is the fan working properly? Is the radiator flowing correctly? Does the rad cap hold the proper pressure?

If this has not been done.It needs to be.
Get the cooling system pressure tested.All that is done is a pump gets fitted to the radiator cap position.It gets pumped up like a pushbike pump and it has a pressure gauge on it.It is pumped up.Let to sit and the gauge is monitored.If the pressure drops it indicates a leakage in the system.Hoses,radiator or even a head gasket.It is a very easy test to be done and it should be very cheap.The other thing is the engine block may have a blockage.After all you have replaced and fixed,there is not much left to do.Get the pressure test 1st.
Is the temp gauge reading hot or is the motor actually boiling?(temp sender unit?)
Hope this helps

If the fans don't come on to cool the radiator then maybe it's the thermal fan switch, which sends the turn on signal to the fan relay, that might be bad.

1. On 2000 Jeep Grand Cherokee 4.7L V8
2. Remove lower radiator hose clamp and lower radiator hose at thermostat housing.
3. Remove thermostat housing mounting bolts, thermostat housing and thermostat.

2000 Jeep Grand Cherokee 4.0l v6Note:on the In-line 6 4.0L model the thermostat housing is mounted at the top of the engine block next to the water pump.

Sounds like your thermostat is stuck closed. Shouldn't be more than a $20 part from autozone and is simple to replace. Follow your top radiator hose to the motor and it will connect to your thermostat housing. Disconnect the hose (antifreeze will run out) unbolt the housing, and replace the old thermostat. Refill radiator and bleed the system.

Sounds like the radiator is clogged, have the cooling system flushed, the water pump pumps water into the engine and it comes out the top hose to return to the radiator to circulate through it to cool, if the radiator is clogged the water pressure will build on the top hose, also look at the bottom radiator hose, if it collapses when you rev the engine the radiator is clogged, although sometimes the bottom hoses are reinforced with wire to prevent them from collapsing so just because they do not collapse it does not mean the radiator is not clogged.

Have you tested the fan sending unit on the engine? disconnect that and if the fan runs (Key on) that is most likely the problem.

When the engine is at operating temp check the electric cooling fan. If it is not moving then i would check the fan relay which is located under the right side headlamp. 9 times out of 10 this is the problem