We had my son's water pump replaced in his 97 F150. It is now occasionally jumping to completely hot. If you turn it off and back on it returns to normal. The power to the engine is cut when it shows to be overheating. The check engine light has now come on.

 

A cooling system is pretty simple. First it’s made up of the following components:<O</O
Radiator<O</O
Lower radiator hose<O</O
Upper radiator hose<O</O
(inlet) Heater hose <O</O
(outlet) Heater hose <O</O
Heater core<O</O
Thermostat<O</O
Water pump<O</O
And the temperature sensor<O</O
Some have a heater control value, some do not
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Water sits in the radiator until the engine temps gets hot enough to open the thermostat. This releases the hot water from the block and introduces the cool water from the radiator. This movement is produced by the water pump. one of the following things are happening:<O></O>
A faulty thermostat, water pump, blockage of some kind prohibiting the flow of cool water into the engine from the radiator. The temp sensor will pick up on the increase in temp and as a failsafe some computers will shut the engine down if the temp gets to hot. <O</O
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It sounds like you have a grip on the water pump.<O</O
I would look at the water in the radiator to insure that it is circulating. Rev the engine a few times. The flowing water should increase in volume at higher RPMS and decrease in volume when idling.If you can’t tell. then squeeze one of the hoses and feel for back pressure (the hose should quickly bulge’s back to normal once squeezed).If these two thing are not happening then it’s a good chance that the pump is fault. Yes is I know it’s new, but I have made many returns to exchange a new part for another new part. OR you can disconnect the inlet heater hose and attach a longer hose and then turn the engine one or two times. If water rushs out of that hose then the pump is pushing the water. if it passes one of these tests then its time to Look somewhere else. you just ruled out a bad pump and or blockage in the flow.<O</O
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As for the thermostat: well you have three choice’s<O</O
1. Let the truck run until you know it hot, about twenty min’s (this varies) once you know its at op tempeture feel the upper radiator hose. It should be hot to the touch. If it is then this tells you that the thermostat opened and allowed the engine water out and allowed the water pump to suck the cool water out of the radiator and into the engine.<O</O
2. Remove the thermostat and bring a pot of water to a boil and drop the lower half of the thermostat in the water and watch to see if it opens. I tie a really long string to mine. Steam burns <O</O
3. Pay about 5-10 bucks for a new thermostat. You replaced the water pump so I normally replace those as a standard practice <O</O
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If your water pump turns out to be good, along with the thermostat then what is left is the temp sensor. You need to know what the standard operating temp of your engine is. Once this is known let the engine run until overly hot (not to hot just above what you know is not normal. Shut it down and find some way to put a thermometer to the water and see if it’s hotter than the standard operating temp. if it’s not then it’s a bad temp sensor.<O</O
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I have been doing my own work for many years. These are some of the tricks I have learned along the way. Just be safe. Your are messing with some HOT, SCARE YOU FOR LIFE WATER.
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You can always take it to someone if you’re not comfortable. Hope this helps

Here’s how to pull the codes on a 2001 f150 WITH OUT A scan tool. It may or may not work for you: hold your trip reset button and turn the key. release the trip reset when the digital odometer freaks out a bit and then shows the word gauge. When the words gage displays (or something other than your trip mileage you’re in) all your gauges should swipe right. If this happens then you’re in the self-diagnostic program of the computer. Just push the trip rest button until you see DTC??????, Push it again to see the next DTC. Keep pushing it to see other info.<O</O

 

David,
thank you for replying so quick and for the information. I gave your suggestions to repair guy and he will take a look. He said it appears everything is working but it's using up water. Not sure what he meant.

He can't get into it until tomorrow.

thanks again,
robert

 

why was the pump replaced to start with ? If the truck has overheated in the past it can have a pin hole in the head gasket... causing the overheat, or the result of it.. If the truck is now "using water" that normally means antifreeze is leaking into the combustion chamber and being burn. YOu could have a cracked head gaseket, manifold gasket or head casting if that is the case. They need to narrow down the problem by testing. Make sure radiator is FULL for the test. See if it leaks down slowly (intake gaskets) or is combustion gases forming in the radiator (head).

 

You are probably right about the casket. Repair guy has not had time to look at it today. I'm wondering what that kind of repair will cost?

thank you for the info. I have sent him thoughts.

robert

 

In your opinion and experience, is a head casket sealer kit worth a try?

I see mixed reviews online and quite a few choices.

thanks again.

 

the head gasket is a major repair,
the order of things from easy to hard is as follows:

1.bad thermostat
2.bad hoses, UPPER AND LOWER RAD hoses, in and out heater hoses
3.temp sensor (this controls the temp gauge in your dash
4. leaking block plug
5.cracked radiater (could be a diy job depending on your exp.)
6. bad water pump (could be a diy job depending on your exp+1)
7.leaking intake gasket (major repair for the undeucated)
8.blown / cracked head gasket (major repair for the undeucated)
9. cracked block (throw the motor away)

one sign of a blown gasket in relation ship to the cooling system is mudding looking coolent. do you have muddy looking coolent?

in order to point you in the write direction we really need to know the results of any testing that yor guy did.

i have never use a head gasket sealer. i have alwayed removed the head, had it chk for warpping, then resurfaced and reinstalled.

 

Why not find the fault before diving into repairs.
If the motor overheats it's due to a loss of coolant or flow.
The cylinder head temperature sensor will cause the computer to go into limp mode over a certain temperature around 230 degrees..
"Allowing" the motor to overheat is a no no if it has no already not been damaged.
Test for exhaust in the coolant, pressure test the system and look at cylinder performance for signs of a head gasket failure before replacing parts from guessing.
Good luck

 

You don't say what engine you have but if it's a 5.4 (not sure about the 4.9)

Just a thought the suggested the intake gaskets get yucky and leak. Just saying this because if the repair guy jumps straight to a head gasket problem make sure he's aware that there is coolant passing through the intake. Make sure he proves to you that it is a head gasket (if that's where he goes) before paying to have that done - it won't be cheap - parts are $1,000 give or take.

There is also a pipe that runs under the intake that could be leaking and you'd never see it until you take the intake off.

 

Run the tests, make sure the water level is correct, see if the tank burps out antifreeze when it gets hot, etc... Look at the intake and under it in the VEE of the motor. Make sure the manifold is not leaking external. If all that is good, and your convinced the head has a crack or leaking gasket, then YES i would try the sealer. I have used the BARS COPPER that you add to antifreeze a few times. Cost is about $10. for a 12 oz (?) bottle. I add the entire bottle to the top radiator hose, then drive down the road at a constant 50 mph so the motor is 1500 RPM, lightly loaded and the thermostat opens. Drive for 15-20 minutes. When you stop, the radiator is pressurized and will push the sealer down any cracks toward the combustion chamber, etc. Next day drive to work normal. Monitor the sytem for a couple days and see if overheating stops. You need to top off the tank as necessary to keep to the correct level. THe spiking gauge is due to vapor lock / air pocket in the water jacket - low water level.