Expedition heater woes, warm then cool air

[joedmti]

I'm a wimp

Bought a new pump today, Napa, $62.

You guys are telling me that the metal fins of these pumps wear off? If so I'll know for sure when I pull my original one out.

How involved is it to change the pump?

Thanks again guys for all the help.

Mangus

No idea about swapping out the pump, got a local mechanic to do it for me.

 

[joedmti]

I thought the same thing

Thanks for the reply. If the water pump is not fucntioning efficiently would'nt the engine overheat? Engine temperature never gets over 180 degrees.

I figured since the engine is not overheating, the pump had to be working, and couldn't be the cause of my "no-heat" issue.

i was wrong.........

 

[mangus64]

Update:

Replaced the water pump today, old one looked good one the way out, fins looked like the new pump. No change in heat. That's ok, water pump needed changed anyhow.
Like I've said earlier the radiator/heater hoses never get hot, just warm. I got aggressive and cut a piece of thin masonite to completely block off airflow to the radiator. I'll force it to get hot.... and it did! I set the idle at 2K RPM via a screwdriver jammed in the throttle cable attachment, let it run for 10 minutes, and all of a sudden I've got pressurized radiator hoses, so hot you cant hold them for longer than 5 seconds. Same with the heater core lines, both hot. Turn the heat on in the cab and lots of heat Funny thing is temp gauge remained right in the middle just like before.

So the dilema is what the heck is causing this? One would assume a stuck open thermostat but I changed it first thing. I put the old one in a pot of water on the stove tonight, it started opening about 180 and was all open by the time the water was boiling.

Is there some sort of bypass in these cooling systems that coolant would be going around a closed thermostat? Maybe coolant is getting around the thermostat?

Also truck started running terrible the other day, missing badly at times. But I'll fix the heat problem first.

Thanks for any help guys.
Mangus

 

[joedmti]

That Suxxx

Sorry to hear the pump wasn't the fix......, I'm lost!

Do you think this could be a radiator issue?????

 

[Racenut]

What has your average outside temperature been at?

Could it be that with the cold weather the mechanical fan is "over cooling" since it is always turning?

Might try covering the lower half of the radiator and see if that helps or go to " Electric Fans " that way you can set a temp for them to come on at.

 

[mangus64]

I'm a bit lost as well.

Does anyone have a coolant flow diagram for these Expys? It is cold up here 20s right now but this rig used to run you out of the truck even at 10 below zero temps outside.

It's basically like the thermostat is open all times. Next step, I will remove the top radiator hose from the radiator side when cold, should not be any coolant flowing until the tstat opens, correct?

Thanks again guys.
Mangus

 

[ELVATO]

Heh, in the service manual, the only thing that it shows for an engine not reaching operating temp is replacing the T-stat.

I would have said the cap, but it usually overheats when one of those fails.

If you try to turn the fan by hand, how easy is it turn turn? It could be locked in place, spinning full speed all the time. Granted, when this happens the engine is really loud.

 

[mangus64]

Could a "clogged" radiator possibly cause this problem I have? An odd thing happened the other day while driving with the radiator air-flow blocked off with masonite. The truck over heated, pegged the gauge finally and still no heat! Just luke-warm air.

 

[mangus64]

Solved!

Took the truck into a good radiator shop. Flushed the system, he said every blast of pressure was excrementing clay like deposits out of the cores. Seems the garden hose flush didnt have enough pressure to move the sediment. All is good now, cept I have to get it running better now, see other thread. Thanks all for the help through this ordeal.

 

[joedmti]

Good to hear

Been meaning to check back on you, was wondering if u got this issue squared away.
Glad to hear you got some heat!