Luke Warm Heat Only

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lorencherylp
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Luke Warm Heat Only

Post by lorencherylp » Wed Dec 04, 2013 11:40 am

I was getting luke warm heat. The heat valve under the hood looked corroded. Found a nice looking one on ebay from Calif. Drained/Flushed/Refill coolant. Still getting same luke warm heat. Any ideas
what is going on? And the temp gauge reads in the normal range. Thank you.

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Grayson
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Re: Luke Warm Heat Only

Post by Grayson » Wed Dec 04, 2013 12:49 pm

I don't know if you did this during your flush or not, but make sure you remove the hoses from your heater core and flush it out independently both directions. I like to soak the core in CLR for at least a half hour before flushing each way, personally.

Beyond that, make sure you're getting good vacuum to your heater control valve.

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John Brennan
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Re: Luke Warm Heat Only

Post by John Brennan » Wed Dec 04, 2013 4:12 pm

Is your air door solenoid (in front of the battery, has a piece of foam in the round, protruding end, connected to a pushrod on top of the heater fan box) working? You should hear the outside air doors close when you turn on the ignition, and otherwise operate the controls of the system. Give it 12V and see if it clicks. If it isn't the doors will fail open, allowing cold (or hot, in Summer), outside air into the system and giving you weak heat or A/C.
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buzz13
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Re: Luke Warm Heat Only

Post by buzz13 » Fri Dec 13, 2013 10:51 am

make sure that you do a flush of all components including the oil cooler as this is where mine was blocked. the service manual has a diagram of all hoses and direction of flows

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anglin
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Re: Luke Warm Heat Only

Post by anglin » Sat Dec 14, 2013 6:14 pm

Consider replacing your thermostat with a Ford/Motorcraft unit. This post will document why it make work for you:

viewtopic.php?t=15972

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