Hello all,

I am new to the forum and I am having troubles with my truck overheating. My truck is a 95 F150 XLT 2WD Ext Cab, 5.0, AT with 125,000 miles.

The truck overheated on me and shot coolant everywhere, I was only 5 miles from home, so I let it cool, filled it with water and drove it home.

Once home I tried to see if I could diagnose the problem.

I took off the radiator cap and saw no churning, I assumed it was the water pump. So I put a new water pump on the truck.

While it was apart, I saw that a freeze plug had cracked on the passenger side cylinder head, so I replaced it as well.

I also installed a new thermostat. Still overheats.

I then installed a new fan clutch, the fan definitely spins much harder and really pulls a lot of air.

I was still overheating. So I went to the local Jiffy-Lube and had them flush the entire system under pressure, and it still gets hot. On a plus side, there are no leaks coming from the engine or any hoses, etc...


I am running out of ideas. When I flip the heater on it does cool it down a little bit, just barely in the "normal" reading on the dash and still much hotter than before.

When I flip on the heater switch I now hear a hissing noise coming from the heater core, after about 2 minutes it goes away, but there are no leaks coming from the heater core.


I also checked the oil, there is no presence of coolant in the oil. There is also no white smoke out the exhaust. So I don't think it is a head gasket.


I am loosing my mind trying to fix my truck. I can drive it about 3 miles before it overheats.


PLEASE HELP!!!

Thanks,
-Eric

 

is it losing coolant and have you checked to see if the heater core is leaking? maybe there is a clog try back flushing it. if the coolant was really bad when you handed it over to jiffy lube they may have lodged something. personally i wouldnt trust a jiffy lube. i have fixed to many of their screw ups when i worked at ford. just my 2 cents

 

pull codes and see if there is anything wrong it might be a bad sensor you never know with these old beasts

 

Also there is a tester that you can use to see if you have exhaust gasses in the coolant that will tell if you have a problem with a head gasket

 

you can also tell if the oil is milky if the oil has antifreeze in it its most likely a blown head gasket

 

Are you SURE it's overheating?
What I mean by that is when it SHOWS that the engine is overheating and you shut off the engine do you HEAR it "gurgling" like it's so hot the radiator cap sounds like it wants to blow off? It may just be the temp sensor
Sorry about the run on sentence.

 

If it blown between a oil & coolant passage you will. If it's blown between a coolant passage & exhaust port or if there's a crack in the head you will get the white smoke out the tailpipe or the exhaust going into the coolant causing motor to run hot & overflow out the radiator.

 

i have similar problem but heater core is bypassed but ive got a leak coming behind the passenger motor mount im pretty sure its a freeze plug is there any way to get one in there? sure could use some idea thanks 5.0 94 ext pickup still runs and sounds decent nothing in the oil

 

X2. As usual I recommend using some gauges here. Check for codes first. It eliminates a lot of guessing and gives solid answers. As usual harbor freight has budget friendly tools or parts stores loan them. Get a cooling system pressure gauge set. It comes with a hand pump. Pressurize the radiator. It should hold. Check for coolant leaks. Be sure to wiggle the hoses. Use the same kit to check your radiator cap. Do a compression test. Check the oil coolant and exhaust. By now you will have eliminated blown or cracked engine parts, freeze plugs, leaks hoses heater core leaks and the cap without spending a dime in less than an hour. Now with a multimeter you can check the temp sender. And check for oil pressure and level. Check timing. Feel the hoses to temperature differential. Make sure the coolant is flowing past the thermostat. If all that checks out you may have to get more invasive and full stuff apart. But its likely you will have found the problem. BTW there is a test for the fan clutch you can do on the site or in a Hayes book. But you just replaced it so its likely good. Just make sure the fans on forward and blowing the right direction.