no heat:

ezernut9mm · Post by **ezernut9mm** » February 6, 2011, 10:03 pm

ok, i replaced my t-stat (the old one was working properly). both are 180* parts. i also replaced my radiator cap. all of this was to address a "whistle" on deceleration after highway driving.
i haven't road tested to see if i cured that problem, but i will this week.
anyways, i have a no to little heat issue.
at an idle from cold the engine will get up to 180 on the gauge and then cool off to around 160 or so. i assume this is the t-stat opening. during this time i have no heat coming out of the heater core. the inlet hose is hot, but the outlet is not. when i rev the engine the temp goes down on the gauge and i get heat out of the heater. not real hot, but heat.
i have made sure the heater core is not clogged by running water through both hoses and it is flowing freely.
this also tells me the heater valve is working.
so basically i have heat in the cab when the engine is running cold and no heat at an idle when the engine is up to temp.
any ideas???

61 Merc · Post by **61 Merc** » February 6, 2011, 10:13 pm

Maybe your flowing the fluid through the core backwards?

Dean

ezernut9mm · Post by **ezernut9mm** » February 6, 2011, 10:16 pm

ooh, kinda like if i play a country song played backwards? i get my dog, gun and truck back?

slick4x4 · Post by **slick4x4** » February 6, 2011, 10:16 pm

ezernut9mm wrote: any ideas???

move to Texas ? ... it never gets cold down there

ezernut9mm · Post by **ezernut9mm** » February 6, 2011, 10:21 pm

i am really thinking about that. looks like it has to be south of dallas though.

Rusted64 · Post by **Rusted64** » February 6, 2011, 10:57 pm

You are welcome to the Houston area.

R Pope · Post by **R Pope** » February 7, 2011, 7:56 am

Air lock? Bleed the system by loosening the top hose at the heater, warm the engine to make pressure and shut it down before bleeding.

ICEMAN6166 · Post by **ICEMAN6166** » February 7, 2011, 10:54 am

the problem is the heater core is plugged.

this is why only 1 hose is hot, nothing flowing thru the core, so just barely warms it up a bit.

you may be able to fix this easily by flushing the core.

go to the self serve car wash, take the heater core hoses off , stick the high pressure car wash hose in one and blast away. make sure to flush both ways.

or you could take out the heater and take the core in the house and make a mess in the kitchen sink.

btw the thermostat ratings are for "fully open" meaning @ 180 the therm has opened all the way. it actually starts opening around the 160 range.

R Pope · Post by **R Pope** » February 7, 2011, 1:59 pm

I'm confused. Why did you change the thermostat to stop a whistle????

Paul Merrell · Post by **Paul Merrell** » February 7, 2011, 6:05 pm

Could the water pump be the problem the impeller gets loose when hot and causes low pump flow.

realisticretiredone · February 7, 2011, 8:16 pm

Do you have the heater control knob on the dash pulled out, if not your only geting heat to the defroster vents

ezernut9mm · Post by **ezernut9mm** » February 7, 2011, 9:45 pm

R Pope wrote:I'm confused. Why did you change the thermostat to stop a whistle????

i changed the radiator cap to see if the "whistle" was escaping pressure, the thermostat was just something i did because i haven't done it and don't know when it was done before. plus it was running cold so i thought maybe it was stuck open.
i probably shouldn't have posted the question yesterday considering all the libations that were enjoyed during the afternoon. lol after reading my post, it really doesn't sound like i thought it would.

brian, i did flush the core. very good flow.
i am starting to thing the water pump impeller is toast as mentioned above. not sure how i would check that though. i guess i would take the pump off and see what i can see. are they "open" on the back side?

ICEMAN6166 · Post by **ICEMAN6166** » February 7, 2011, 10:10 pm

so i read the original post again.

you are heating up the core while the thermostat is closed (warmup) and this is correct as the hottest coolant is on the block side of the t-stat and exits before the t-stat into the heater hose.
its after it opens the heat goes away. low coolant level will also cause this.

i just dont think you ever get enough heat out of a 180* thats why i have always used a 195*.

Astrowing · Post by **Astrowing** » February 7, 2011, 10:32 pm

Hey it does get cold in Texas! Why just last week it was 23F here and the ice on the elevated freeways provided a situation that Houston drivers can't handle. PIttsburg and Green Bay both moved their practices indoors in Dallas because they couldn't handle the cold.

I agree with the 180 degree causing the engines to over-cool with those little engines and huge radiators really designed for larger trucks that are working hard. I'm thinking about putting a 195 in mine now. It's really better for engine wear if it doesn't cause heating issues.

R Pope · Post by **R Pope** » February 8, 2011, 7:18 am

If the engine is cooling it won't be the pump. Try covering the rad with a few pieces of cardboard. That'll get the temp up enough to tell if the heater works. Just keep an eye on the temp gauge. My 240 six needs a solid piece of cardboard blocking all air flow to get any heat in -20 weather. Even then the heat gradually decreases on the highway, comes back up in town.

ICEMAN6166 · Post by **ICEMAN6166** » February 8, 2011, 12:26 pm

R Pope wrote:If the engine is cooling it won't be the pump. Try covering the rad with a few pieces of cardboard. That'll get the temp up enough to tell if the heater works. Just keep an eye on the temp gauge. My 240 six needs a solid piece of cardboard blocking all air flow to get any heat in -20 weather. Even then the heat gradually decreases on the highway, comes back up in town.

195* puts out great heat in a 6 cyl @ -25F, no loss at highway speed.
never been cold in a ford truck yet.

i do see some cars/trucks with cardboard but i refuse. heater either works or gets fixed so it does.

ezernut9mm · Post by **ezernut9mm** » February 8, 2011, 5:09 pm

this is the first ford truck i have owned that didn't heat properly.
i will try flushing the core again, but it flowed strong the last time i did it. is it possible that there is stuff (rats nest) in the box? i might take the cover off and see what the core look like.

charliemccraney · Post by **charliemccraney** » February 8, 2011, 5:46 pm

Neither of the hoses is clogged or collapsed?
You could, just for fun, switch the hoses at the heater core. I think it can matter which one is the inlet and outlet. If the top is used as the inlet and there is an air pocket, the air pocket may remain because the coolant flow is going opposite the direction the air pocket wants to travel. If the inlet is on the bottom, the air pocket can more easily escape since it is going with the flow.
Here in Atlanta, my heater does a fine job with a 180 degree thermostat. It'll get it hot enough that I have to turn it off. Assuming no significant holes in the cab, I can guarantee, teens and above it will do fine.
How do you know the valve is working? I didn't understand that part.

R Pope · Post by **R Pope** » February 8, 2011, 6:02 pm

Wouldn't want to argue about cold weather with an Alaskan, but very few cars or trucks run warm enough in the Prairies without a cover on the rad. Blowing snow kind of overcools anything.

62galxe · Post by **62galxe** » February 8, 2011, 7:55 pm

ive seen a six in a falcon that didnt overheat with the fins on the water pump missing. heater didnt work very good.

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