Heat Problem

When I turn on the heat I get good heat for about 5 seconds than it goes cold. If I turn the control off for a few minutes then turn the heat back on, same thing.

I battled this problem last winter also without ever finding the fix. The core was flushed and the themostat was changed. Could it be the pump or blend door?

What does the temp guage do during this time? Similar concerns have been addressed on this forum numerous times. I suggest you search the forum for key words.

Typically, I suggest that you may have an air pocket in the cooling system, especially since you've had the system flushed and the thermostat replaced. Other's have posted suggestions as well, so perform the search.

-Rod

You can try this. Park it front high on a very steep hill, let it cool down and remove the reservoir cap & leave it off. Crank it and rev it up to 2000 rpm and hold it there for 15 seconds or so then let it idle a minute then rev it up again. Do that a few times and if you have a bubble hopefully it will go to the highest point and come out the reservoir cap. While you're doing this make sure the control is on heater wide open.

"Could it be the pump or blend door?"
Not the water pump because it would run hot all the time. Blend door - I doubt it. If you have a bubble that big I don't understand why the engine doesn't run hot. If you hook the inlet/ pressure hose up to the core top pipe-outlet the core never fills up so you don't get the core full. In other words, the pressure hose should be on the bottom heater core pipe so it fills up from the bottom and pushes the air out the top. People use to come into Dads radiatior shop with the hoses reversed wondering why they weren't getting any heat and he would switch the hoses around and bingo, immediate heat.

BE VERY CAREFUL AND USE DUE CAUTION IF YOU DO THIS: One way you can test it would be feel the heater hoses with it running and see if they're hot, the inlet hose should be very hot and the outlet not as hot.

"When I turn on the heat I get good heat for about 5 seconds than it goes cold. If I turn the control off for a few minutes then turn the heat back on, same thing." Sounds like a little coolant is trickling into the core then when you turn the heat on it's gone quick.

OH! I just remembered something. A guy said he had that problem and they had stuck a piece of paper down in the heater core pipe, packing ticket, shipping reciept or something like that, and it got shoved down in it and blocked the water flow and they almost never found it. But, you said they flushed the core so I guess they were content with the amount of coolant passing thru it.

I'm 90% convinced you have a bubble in the core so go ask the guys at the Ford place how they correct that problem.

Mystery solved. I took the car to my local mechanic and after trying a few things he changed the water pump. The pump blades were shot. Good heat now. Total cost - about $150.

It's gonna be a comfortable winter afterall.

Thank you for the follow-up. It's getting to be the time of year where this info may be of tremendous value to some!

-Rod

Mystery solved. I took the car to my local mechanic and after trying a few things he changed the water pump. The pump blades were shot. Good heat now. Total cost - about $150. It's gonna be a comfortable winter afterall.

What do you mean by "shot"? Were the blades eaten up by electrolosis or just worn down so not pumping much water? They make "water pump lubricant" additive and might be a good idea to dump in a can of that. Many years ago my Step Dad had it tested and it was water soluble oil and food coloring. Yup, oil that readily mixes with water, never knew there was such a thing.

Warn down.

"Worn down." Must be a heck of a lot of miles on it or they used battery acid for anti-freeze. <Grin> Seriously, I never saw a water pump with blades, "worn down." I've seen leaking water pumps and squealing pumps, but none with worn down blades so much so it didn't pump sufficent water flow to cool the engine and heat the car in winter.

By the way. Was at Advance Auto browsing and they had a product on the shelf in a quart container that essentially said, drain everything out of your cooling system and use just this, it is anti-freeze, water pump lube and a water wetter to make coolant more efficent. Hmmm . . . . A quart of it will do all that? Seriously doubt Detroit will ever use it because they have a big contract with Prestone and whatever that pink stuff is GM uses.

Water pump impellers on Taurii wearing down seems to be a rather common issue. There have been quite a few postings on this forum related to similar findings.

As for what you found at Advance, I suspect the instructions said to drain the system (to get all the old contaminated coolant out), add the quart of "miracle stuff," then fill the system with fresh coolant of the proper mixture. Or possibly drain a quart of coolant out to make room for this additive. Since the label said it is to make coolant more efficient, that would translate to this item being an additive to coolant, not a stand-alone.

There is no way you could use just one quart in a 13 or so quart system and expect the PCM to function properly (since the temp sensor would be reading air), the heat to work (since the heater core would have no fluid in it) and the engine not to seize (since there's no liquid cooling the water jackets).

-Rod

"There is no way you could use just one quart in a 13 or so quart system and expect the PCM to function properly" <Grin> Now you should know this old geezer knows better n' that. You drain and flush it then put the stuff in and fill it with water same like anti freeze. Maybe I mis-read the label and I'll swing by this week end and read the container again and get the name, but I thought it said that one quart is all the system required with no anti freeze.

This summer I got some of that Water Wetter on sale and put in in the Taurus and Marquis and I got the impression that stuff was the same thing PLUS anti-freeze. I can tell my dyslexia is getting worse with age, so maybe I misinterpreted the label. I'm on your page and seems wierd how a quart could take the place of a gallon of anti-freeze.

I think I have the same problem. I get heat on warm days and when I'm going 40mph or more. I've replaced the thermostat and flushed and refilled the coolant. I'm replacing my water pump in the morning hoping it will solve the issue.