1997 F150 Running cold
01-19-2010, 03:15 PM
#1
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1997 F150 Running cold
Hello F150 forum, I have a 97 F150 4x4 with 5.4L. It runs cold and blows cold air when heater is turned on. I just replaced the radiator, thermostate, cylinder head temp sensor, and water temp sensor. I can't figure out why it wont warm up and blow hot air when I use the heater. Any advise on what to check next or if you had the same problem how did you fix. Thanks
01-19-2010, 05:08 PM
#2
Senior Member
You say it's running cold. Even the temp gauge showing
cold? Are both heater hoses also cold? How about the
top and bottom radiator hoses?
Need those questions answered to try and help...
Good luck
cold? Are both heater hoses also cold? How about the
top and bottom radiator hoses?
Need those questions answered to try and help...
Good luck
01-19-2010, 05:20 PM
#3
What was the initial problem? (you changed many things)
Did you put the t-stat in the right direction?
could be bad gauge, broken wire, faulty t-stat, plugged heater core, non working duct work or temp controls, AC staying on? the temp sending unit must have water contacting it. Need more information.
Did you put the t-stat in the right direction?
could be bad gauge, broken wire, faulty t-stat, plugged heater core, non working duct work or temp controls, AC staying on? the temp sending unit must have water contacting it. Need more information.
Last edited by Thunderslide; 01-19-2010 at 05:28 PM.
01-19-2010, 05:24 PM
#4
Censored by the Man
Is you coolant topped off? Maybe an air bubble came out. When the coolant level drops the heat is the first thing that goes. I just experienced this with two seperate cars.
01-20-2010, 09:50 AM
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1997 F150 running cold (details)
Thank you all for responding, the initial problem was the stat froze closed and the radiator blew, I replaced the 2 row radiator with a new one and a oem (192) temp fail safe stat, flushed the system, and burped the lines after fill. Noticed it running cold on the gauge (when it is warmed up guage reads 1/4 past lower normal operating temp line, while driving it drops to the lower line or below depenging on outside temp.) I replaced the stat again with a oem stat and temp came up alittle. Then I started replacing sensors (its a 97) thaught it couldn't hurt. No luck. All hoses are hot to the touch after truck has been run for a while. When I use the heater, no matter what zone it is on it blows cool air. The AC does not work, the pump doesn't kick on when turned on. Thanks again.
01-20-2010, 10:13 AM
#6
Do you have access to a mechanical gauge? I would try that first. If the temp drops when you get moving I suspect the t-stat is staying open. with the engine running (cold) take the pressure cap off the radiator. in a closed system when the t-stat opens you should be able to see flow. if it is moving right away you have a bad t-stat. Not being there is hard to know what is going on.
