running too cool

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Jun 21, 2014 | 08:04 PM

breeze3215

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running too cool

My 73 f-100 with a 302 doesn't heat up to where it should.I have the stock gauge.I know these aren't accurate at all,but can tell by the heater blowing barely warm air and condensation on my oil filler cap,that it's running too cool.I just put in a new radiator,cap,water pump,thermostat,and coolant and it's still running the same.I did replace the intake gasket awhile back but can't remember if it was running cool before then or not.Any ideas?Would my timeing being off a little cause this?

Jun 21, 2014 | 08:43 PM

co425

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Did you get all the air out of your coolant system when you refilled it? Is your new thermostat stuck open? Also time for a new water temp gauge, the stock ones are mostly useless.

Jun 21, 2014 | 09:15 PM

breeze3215

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I think I got it burped good.This is the third thermostat I've tried,same results.

Jun 21, 2014 | 09:52 PM

dlburch

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From: Kansas

have you tried flushing water through the heater core?

Jun 22, 2014 | 06:51 AM

Blue and White

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With a working T stat it "should" warm up but isn't. I wonder what's going on.

Does the gauge move at all? For example will it move up to mid range at least during a long high(er) speed run at summer temps? Pushing these trucks at 70 or so takes a lot of power and should warm it up even without T stat. If the gauge does not move under these circumstances it is suspect.

How does the T stat sit in the housing and water neck? Is everything reasonably snug and in good condition? T stat right side up?

How about the stat itself? Is it factory rated in the 192-195 degree range? I've had best luck with better grade parts store replacement stats.

Jun 22, 2014 | 10:44 AM

lee

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Joined: Jul 1999

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From: Lacey, WA

You have recieved great replies!

My only comment would to be: With the engine bone cold, take off the radiator cap, crank the engine and with it cold look into the radiator to see if you can see coolant flow. If the stat is closed you should not see any flow. If you see flow your stat is open when it shouldn't be.

Jun 22, 2014 | 04:15 PM

Red Mercury

Tuned

Joined: Mar 2010

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Quote:

Originally Posted by dlburch

have you tried flushing water through the heater core?

Yes, check the heater core--it could be fooling you. It could be partially plugged too and not letting enough coolant flow through it to produce sufficient heat from the heater.

How hot does the top radiator hose get after the truck is well warmed up after a highway trip? It should be hot enough that you can hardly hold your hand on it. Once you have determined that then you can take a look at the temperature sender, gauge, etc. Sounds like you have pretty much eliminated the defective new thermostat possibility after 3 replacements.