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i've posted on jan 18 about my cooling problem on a 97 expedition 4.6 L . i have changed thermostat 2x's in case i brought bad one ;changed degas bottle cap; checked radiator -off vehicle -water flow is good . taken off water pump inspected it - look good,not loose,no play,no noise,no leaks at weep hole - reinstall water pump !! The engine was running good with no missing , no steaming from tailpipe,no oil in water,no water in oil. coolant rises after running normal for a while - degas bottle over flows !!!! how do you check clutch fan and how can i rule out head gasket ? I appreciate any feedback on this - thanks
What does the engine do? I haven't read you're post having a problem>
You're fan, turning it by hand should seam somewhat tight to turn, with no play in it if you try to wiggle it side to side, or back and fourth.
thanks for responding - ubereal2 and 2000expy . i first posted this problem on jan. 18, the engine runs normal until it suddenly just start boiling over out of recovery tank. the temperature hand stays in normal position for awhile 5-10 minutes or riding for 1/2 or more miles, than it just suddenly runs hot with check engine light and oil light coming on. stopping engine for 3-4 minutes and restarting all back to normal ...i install new bottom hose ;check clutch fan movement-feels tight when turning;no play in up/down/side/side.. i am taking out thermostat to see what happens. will post back later .. thanks for inquiring.
I am getting close to solving the over heating/boil over problem. the last thing i did was to take out the thermostat . for trail purpose running with water and no thermostat - i run the vehicle for 5 miles or so , and the temperature hand stay on cool to cold . no boilovers;no check engine light;NO HEAT IN AUTO EITHER. tommorrow i will try the 3rd thermostat. (brought 2 - my old one checked out good in boiling water as new ones. if it was not so cold in vehicle i would run it without thermstat.QUESTION what makes it run hot with thermostat ????? hope it was just a coincident ....
Try a different brand of thermostat. Maybe just a bad design. Also make sure you are installing it in the right orientation. If it's upside down, that will cause problems.
No without the thermostat installed you won't get much for heat. When the engine is cold, the thermostat is closed. Keeping coolant in the engine block until it gets hot enough to open, then letting more coolant in. This opening and closinig gets all of you coolant warm, getting you heat. Without a thermostat, water/coolant just circulates, not staying in the engine block to heat up. So you won't get heat, but you will get a cooler running engine. This can also through off you're the vehicles PCM. Try a good brand of thermostat. Make sure it's installed with the spring towards the engine. Bob
thank you all for the replies; the latest - i reinstalled new thermostat and the problem came back again. so i guess there is some kind of problem with thermostat insalled. could there be some kind of control somewhere in coolant system that could be electrically controlled.i am taken thermo back out again and drive with out for awhile. any suggestions please post..thanks
possible ignition problem..causing the engine to work against itself. Try power-reset on the ECM by disconnecting the battery...should set everything back to factory defaults
the radiator was taken out of vehicle and garden water hose water through it ,flow was good, no rust or other contaminant.antifreeze was clean when drained. what led up to problem - about a week of adding coolant (1 gallon).noticing temperature hand rising to hot. it just happen suddenly not months in the making.
Since you have checked just about everthing else, this is looking more and more like a bad head. How hot is the heat form the vents when the temp(gauges) starts to climb? Is it hot enought to chase you out of the truck or does it start to drop off?
Last,and most expensive test would be a cylinder pressure test, but that is about the only thing left. Hopefully during this test he head is warped bad enough when cold too and not only when it is at operating temperature.