Overheating engine

TERRI LYNN THACKER-STOOKSBURY

MEMBER
1998 FORD F-150
4.2L
V6
2WD
MANUAL
231,000 MILES

My truck has been overheating, but this last time it actually had steam rolling from under hood! Changed the thermostat, went to refill coolant fluids and it ran all over the ground. We thought we blew a freeze plug but those seem to be okay. We believe or have been told the heater core is possibly out and may have a bad sensor within the system. What is your opinion? If we bypass the heater core, how can we check sensors within the cooling/heating system to determine if we have a faulty sensor? Thank you for your help.

1 Reply

JACOBANDNICKOLAS

MECHANIC
108,489 POSTS

Hi and thanks for using 2carpros.com

If the heater core was leaking, the coolant would leak into the cab of the truck. If that isn't happening, then chances are it is not the problem.

Make sure all hoses are good and not broken. Make sure the radiator isn't split and leaking. Also, check the water pump on the front of the engine. There is a weep hole where coolant can leak from when the seal / bearing goes bad in the pump.

If you look through this link, the second picture shows what I am referring to.

https://www.2carpros.com/articles/symptoms-of-a-bad-water-pump

If possible, let me know aprox where the coolant leaks from. That way, I can help pinpoint where it may be coming from.

As far as a sensor, coolant temperature sensors are located on the engine, so again, the heater core has nothing to do with it.

Let me know,
Joe