Operating temp stays low

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Ultimatefit23

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My 5.7 vortec wont reach normal operating temp. Top radiator hose as well as the bottom only get warm to the touch no matter how long truck runs. I have minimal heat inside vehicle. Need a little help here, what could be the problem.
 

Doubeleive

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most likely the thermostat is stuck open, have you done any work to the cooling system previous to this problem?
 
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Ultimatefit23

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Suspected engine to have had blown head gasket ( I was wrong) used bars gasket seal. Flushed entire system and heater core. Also replaced radiator. Replaced coolant, made sure to get all air pockets out of system.
 

Cliffjrs

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Suspected engine to have had blown head gasket ( I was wrong) used bars gasket seal. Flushed entire system and heater core. Also replaced radiator. Replaced coolant, made sure to get all air pockets out of system.
Had the same problem and changed the sending unit. All is good.
 

willxfs

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There are two sending units on my 1998 two door rig. One sends temperature info to the computer the other sends temperature info to the dashboard gauge. One is located near the thermostat housing the other on the block below the head on the drivers side. I cant recall which one sends info where. If you have a scan tool you can read the temp that your computer is seeing. If that sensor is bad then your truck may run bad. If the other sensor that feeds info to the gauge is bad, then all you see is an inaccurate temp on the gauge. Neither of these two potential problem sensors explains why you dont have any heat from your ac/heating system. The likely suspects are a thermostat that is stuck open, a clogged up heater core or a bad heater valve. Below is a pic of the heater valve. Its on the passenger side a bit in front of the fire wall. Good luck and keep us posted.
15-5533_Primary__ra_p.jpg
 

iCajun

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Likely the thermostat is not closing. I've had a few do that over the years.
 
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Ultimatefit23

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Will be working on it again this weekend. Plan on changing it next, hooe that's it. Will let you know.
 

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