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Cooling system issues.

Truck is a 93 F150 2wd with a 5.0L

Oy where to start on this one... After spending the better half of the morning removing the passenger side motor mount to verify that one (or both) of the freeze plugs on the block were leaking, they were in fact just fine; however coolant is accumulating on the battery positive cable which is right under that mount (also the lowest point in the cable routing). The slit in the cable shielding was facing up and when I opened it up, a good trickle of coolant came out of it, so we know it's getting into the cable from somewhere.

But wait there's more. I've also got coolant starting to drip down from the bellhousing. It's very light and I can't see the back of the motor very well to see if it's the lower intake gasket leaking but that's a possibility. Anywho moving to the front of the engine I can see where coolant has been running down from the thermostat housing and can see a pool where it's accumulated on the block. I believe what it's doing is it's running down to the oil pan gasket and then hitching a ride to the backside of the engine but regardless that needs to be fixed since it is leaking which brings me to problem #3.

The third problem I've noticed today after the truck sat and idled for about 20 minutes in 60*F temperature. It's building up a lot of pressure in all the hoses but both upper and lower radiator hoses were still cold (by cold I mean you can touch the hose and feel hardly any if no heat from the hose.) What is striking me as odd is both heater hoses that run off to the heater core are hot yet the upper and lower hoses are still cool. When I hook up the scanner to the truck the ECT reading never gets above 170*F and usually hovers around 160 or so. The thermostat is a 195*F and was replaced a little over a year ago.

I'm a little stumped on all this. I've got the truck back home and can diag/work on it tomorrow if someone on here can help me hash up a plan of attack on here. Thanks for reading.
 
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So it's building up lots of pressure in all the hoses except for the upper / lower radiator hoses and the heater core hoses? Exactly which hoses ARE building up pressure and getting hot?

If I were doing this I would hook up a pressure tester to the radiator and pressurize the coolant system. That way you can look for the leak with the motor off and cold.
 
Didn't have access to the pressure tester today at work or else I would have used that. All hoses are building up pressure. The upper and lower radiator hoses are not getting hot but the heater hoses running off to the heater core are.
 
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I missread the part about the heater hoses.

So the radiator hoses are not hot but have pressure? That does not add up.

I would use a pressure tester to find leaks.

To find why it's hot in some areas and not others I would look into the possibility that there is a lot of air in the system, bad t-stat, blockage in the radiator, bad water pump etc. To pin it down I would check the coolant level and use a laser thermometer and take reading all through out the coolant system; that should give you an idea what / where the problem is.
 
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Upper radiator hose - not hot, lots of pressure

Lower radiator hose - not hot, lots of pressure

Heater hoses to heater core - hot, lots of pressure

I did top off the coolant before doing this test and watched for bubbles while it was running and when the bubbles stopped I then put the cap back on and let it run for a good while. I agree that something is amiss in the system and I'm just trying to pin it down.
 

TexasNomad

FTFS Designated DRINKER!
I had a very similar issue and after changing my thermostat flushing the system and lots of cussing it turned out to be my water pump..
But I would do a pressure test and try ever tying else before dong a waterpump job.
If you never done one it can be a real pain in the rare.
 
Oh trust me, I've done a water pump on a 3.0L V6 ranger. After looking at the front of the 5.0L it's bringing back memories, especially since the P/S bracket assembly will probably have to be shoved to one side.

To be honest that looks to be the factory W/P on this truck and last time when I replaced the thermostat I was really cursing it since the waterpump was in the way so I'll probably just replace both and go from there. Probably overkill on the water pump but it'd give me a little better piece of mind.
 

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