Cooling issues
Thread Starter
Junior Member
Joined: Mar 2016
Posts: 3
Likes: 1
Cooling issues
Hello all first timer here, feel free to haze as needed.
1995 f150 swb single cab 4.9L Mazda 5spd 4x4 220,000 miles
So i have a strange cooling problem: Today I turned my truck on started driving, and it got warm (gauge showed) then it kept going up, all the way up to H. So I pull over, pop the hood and get out and this is what I find- everything is cool to the touch, radiator cap, valve cover and even the cylinder head didn't burn me when I touched it. Upper radiator hose is warm, but not hot like it should be. Coolant level seems fine in degras tank and the radiator was under pressure so I didn't take cap off. So I get back in the truck turn it on and I'm getting full heat. So I keep driving and after a long while the gauge drops down to where it should be. So I pull over again to check it out and all the symptoms I described above are still there.
I can't figure this out. That heat from this 4.9 is going somewhere but where?
Forget about what the gauge is showing, even if the thermostat is faulty, which would seem to be the case i still have another problem- why can I touch the cylinder head without getting burned? The thermostat is a mechanical device that controls itself, even if it was stuck open then could it cool this big six that much? Doesnt seen possible. Given this being true is the temp sensor and or the switch at fault?
Lastly this truck has had a new radiator, fan, hoses, thermostat and housing ( both motorcraft) and temp sensor in the past 2 years or so.
Any advice would be appreciated. Thank you all
1995 f150 swb single cab 4.9L Mazda 5spd 4x4 220,000 miles
So i have a strange cooling problem: Today I turned my truck on started driving, and it got warm (gauge showed) then it kept going up, all the way up to H. So I pull over, pop the hood and get out and this is what I find- everything is cool to the touch, radiator cap, valve cover and even the cylinder head didn't burn me when I touched it. Upper radiator hose is warm, but not hot like it should be. Coolant level seems fine in degras tank and the radiator was under pressure so I didn't take cap off. So I get back in the truck turn it on and I'm getting full heat. So I keep driving and after a long while the gauge drops down to where it should be. So I pull over again to check it out and all the symptoms I described above are still there.
I can't figure this out. That heat from this 4.9 is going somewhere but where?
Forget about what the gauge is showing, even if the thermostat is faulty, which would seem to be the case i still have another problem- why can I touch the cylinder head without getting burned? The thermostat is a mechanical device that controls itself, even if it was stuck open then could it cool this big six that much? Doesnt seen possible. Given this being true is the temp sensor and or the switch at fault?
Lastly this truck has had a new radiator, fan, hoses, thermostat and housing ( both motorcraft) and temp sensor in the past 2 years or so.
Any advice would be appreciated. Thank you all
Senior Member
Joined: May 2013
Posts: 1,031
Likes: 263
From: Clinton, Tennessee
Our old straight 6 cylinders do run cool. My temperature gauge doesn't ever go 1/2 way up on a 100 degree day. If you have good heat (which you said you do), i wouldn't worry about it.
Someone else will chime in and say what they think about it
Someone else will chime in and say what they think about it
Temperature sender is located at the rear on the passenger side, just below the last intake runner. Like nrivera04 said, it could be a faulty sender (not to be confused with the sensor at the front).
Sounds like your gauge said the engine was very hot but it wasn't according to your observations.
Sounds like my son calling me when his car (with tire pressure monitors) kept telling him one of his tires was low. He was quite concerned because even after checking all the tires with a gauge the car kept saying one tire was low.
His car was lying to him - your truck may be too. It's just an electric gauge hooked to a resistance based sender.
All it's really good for is telling you if things are different than they were before, and it's 20 years old.
Sounds like your gauge said the engine was very hot but it wasn't according to your observations.
Sounds like my son calling me when his car (with tire pressure monitors) kept telling him one of his tires was low. He was quite concerned because even after checking all the tires with a gauge the car kept saying one tire was low.
His car was lying to him - your truck may be too. It's just an electric gauge hooked to a resistance based sender.
All it's really good for is telling you if things are different than they were before, and it's 20 years old.
Thread Starter
Junior Member
Joined: Mar 2016
Posts: 3
Likes: 1
Thanx for the swift replies everyone.
I'm putting a new temp switch in tomorrow atleast for peace of mind. I might replace the sensor too- still under warranty.
If it persists after that I think an aftermarket gauge will be the way to go. Maybe a nice 3gauge cluster on the a-pillar, I've seen autometer makes everything I'd need for that. Any reviews about autometer?
I'm putting a new temp switch in tomorrow atleast for peace of mind. I might replace the sensor too- still under warranty.
If it persists after that I think an aftermarket gauge will be the way to go. Maybe a nice 3gauge cluster on the a-pillar, I've seen autometer makes everything I'd need for that. Any reviews about autometer?