Engine runs cold

Tiny
FUBARGRN
  • MEMBER
  • 1998 FORD F-150
  • 4.2L
  • V6
  • 2WD
  • AUTOMATIC
  • 135,000 MILES
My radiator is slowly leaking from the passenger front corner (near petcock), and the upper hose never really got tight, so I replaced the thermostat and pressure cap. Now, I cannot get the truck to warm up, or blow hot air through the HVAC system. Temp gauge never gets higher than a few ticks above cold. Upper hose flows water when taken off, so water pump is pumping.
Tuesday, January 12th, 2016 AT 12:05 PM

12 Replies

Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
Pull hvac fuse inside truck it may be the blend door actuator needs to be reset or it's bad.
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Tuesday, January 12th, 2016 AT 12:31 PM
Tiny
FUBARGRN
  • MEMBER
  • 3 POSTS
Blend door actuator would cause the truck temp gauge to never really rise?
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Tuesday, January 12th, 2016 AT 12:40 PM
Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
No not that but it can be a problem for no heat. Check your coolant level as you may have air in system and not be full. What temp was tstat if it wasn't 195 then it was wrong temp and that may be the real problem. Make sure both hoses leading to heater are hot as well. The temp gauge may be wrong as well. Even if it worked right before.
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Tuesday, January 12th, 2016 AT 1:03 PM
Tiny
FUBARGRN
  • MEMBER
  • 3 POSTS
Blend door is working, coolant levels are normal, No hoses are getting hot. Standard 195 degree thermostat was replaced yesterday. I can squeeze upper hose with pressure cap off, and can see coolant flowing into the de-gas bottle. Water pump is pumping. I removed upper hose when engine was "cool" and water flowed like a flood when I started it up.
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Tuesday, January 12th, 2016 AT 1:08 PM
Tiny
HMAC300
  • MECHANIC
  • 48,601 POSTS
After truck is warm with engine off and fans not able to start, feel radiator in different spots it should be warm all over if not the radiator may be bad and with outside temp being cooler weather may be the cause. I can't think of anything that will cause this especially with a new rad cap. Unless it's the wrong cap
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Tuesday, January 12th, 2016 AT 1:23 PM
Tiny
BOBRLANE
  • MEMBER
  • 1 POST
  • 1997 FORD F-150
  • 4.7L
  • 297,000 MILES
Vehicle throws out no heat after driving it two to four miles the oil light comes on and temperature gauge goes up past H.
After pulling over and turning ignition off for three or four minutes the temperature gauge goes to normal range oil light goes off and it throws out good heat.
Had it into a mechanic and they replaced a sensor under the intake and this did not solve the problem.
Please help. Thank you.
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Thursday, July 30th, 2020 AT 10:23 AM (Merged)
Tiny
SCGRANTURISMO
  • MECHANIC
  • 4,897 POSTS
Hello,

I would recommend doing a compression test on your vehicle. Also I would check the engine oil to see if it looks like coffee with creamer in it. It sounds like you might have a blown head gasket. Here are a couple of links below explaining a couple of different test you can do to check to see if your vehicle does have a blown head gasket:

https://www.2carpros.com/articles/head-gasket-blown-test
https://www.2carpros.com/articles/how-to-test-engine-compression

Also here is another one:

https://www.2carpros.com/articles/coolantantifreeze-in-the-engine-oil

Please go through these guides and get back to us with what you find out.

Thanks,
Alex
2CarPros
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Thursday, July 30th, 2020 AT 10:23 AM (Merged)
Tiny
KOMETLUVER
  • MEMBER
  • 2 POSTS
  • 1996 FORD F-150
  • 210 MILES
Truck starts cold, runs smooth. It seems as soon as something tell it that it has come up to temp, RPM increases drasticly (2000-3000)RPM. I have replaced the MAF, IAC and the TPS. Only code I get is a low temp sensor reads low, then high after issue starts. Once issue begins if you place truck in drive it will die, will only start with throttle floored and will not stay running. Check engine light is on. No apparent vacuum leaks. Let sit for 24 hrs and starts and takes load fine untill warm-up. Seems like a mechanicaly induced vacuum leak at running temp? HELP
Thank You,
Randy
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Thursday, July 30th, 2020 AT 10:23 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 109,755 POSTS
Randy, replace the ambient temp sensor. It sounds like it is causing the vehicle to get too much fuel when it is hot.
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Thursday, July 30th, 2020 AT 10:23 AM (Merged)
Tiny
KOMETLUVER
  • MEMBER
  • 2 POSTS
Thank You, Will try ASAP!
Randy
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Thursday, July 30th, 2020 AT 10:23 AM (Merged)
Tiny
TOM EDWARDS
  • MEMBER
  • 1 POST
  • 1995 FORD F-150
Engine Performance problem
1995 Ford F150 V8 Two Wheel Drive Automatic

when I first start it and the motor is cold it runs ruff if you let it worm up a little it runs ok
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Thursday, July 30th, 2020 AT 10:23 AM (Merged)
Tiny
RASMATAZ
  • MECHANIC
  • 75,992 POSTS
Clean out the idle air control valve and see what happens
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Thursday, July 30th, 2020 AT 10:23 AM (Merged)

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