Help with my van

[Michael Bullington 5]

Maybe some of you mechanics can give me some ideals about an issue my ford van is having...(OK i know its a ford but it was cheap and it gets us where we are going) now on the problem.

The heater is blowing cold air (except when the engine is over 2500 rpm) it blow hot are as long as the engine is over this RPM ...if you have to slow down for a light it starts blowing cold again.

We have already had the raditor flushed with new coolant , which did nothing,,,but it needed it anyway.

The shop says the Thermostat is working...(I think this is the problem myself, but they said it was okay.. What do yall think?

[pond195520032003 27]

the thermostat could be working just opening too soon i bet if you go ahead and buy a new one it will fix the problem also maybe the heater box door is not opening all the way you could also try moving the heater controlls to see if one might be partially stuck good luck and keep us posted :whistle:

[Nick 13]

Im not a mechanic (brothers took all those genes) but did they check the heater core and as Greg said the heater box mixing door ?

Maybe Once on the coldest day of the year had a 97 F150 heater start blowing cold air. The Ford dealer said it wasnt covered under the extended warranty, that they had sold on the truck, because something had went down the heater vent and blocked the heater box door. The repair estimate was $1,500 to pull the dash. Took it to my brother and he found that the heater control had no power to it. So he installed a free jumper wire with a fuse and it worked fine. :whistle:

[linen beige 15]

It sounds at first as if the thermostat is not closing, but it would take a few minutes of low rpm running to cool off the heater core enough so that you noticed a difference. Just to be sure you can take off the radiator cap and start the engine. Watch the coolant in the top of the radiator. It should NOT be circulating coolant until the engine reaches operating temperature. When the engine warms up and the thermostat opens you will notice coolant flowing into the top of the radiator. The coolant my even suddenly start to flow out through the filler neck, so stay alert for this! A stuck thermostat can also cause the engine to run at a lower or higher temp than normal and that would show up at the guage if it has one. Some engines with stuck thermostats run much cooler than normal, some much hotter.

But it sounds more like you have an issue with the plenums in your air flow control box(es). If the plenums move out of position at low idle then no air is flowing through the heater core, hence no heat entering the airstream. Most of these are controlled by vacuum motors, so I would check for a leak in the lines or a bad diaphragm in one of the motors. Make sure to check all the vacuum lines that may be connected to the system. Some of the pollution controls may change vacuum routing at low engine speed, and could be robbing vacuum from the heater system. Also check the heater controls themselves. A lot of Ford products use vacuum inside the controls. It could even be as simple as a control arm on the plenum being loose, broken, or unhooked. Try out the air controls in ALL of their combinations of settings. If something doesn't seem right, start digging under the dash.

A couple other things to check are the fan speed (does it slow down noticably at idle?) and the fresh air intake filter if the van has one. If it has a clogged filter the heater fan won't be able to pull air through it, but air may be forced through at road speed.

Good luck Mike.

[Michael Bullington 5]

jim i think you right that rules out the theromostat because the air changes immediately when you drop below 2500rpm

for instance when i stop it get cold if you go to neutral and rev it to 2500 its hot again...let off to ide and it get cold immediately

[linen beige 15]

I know it may be hard to hear with the van running but when you slow it down do you hear anything moving under the dash? Plenums don't normally make a lot of noise when they open and close, but the sound of the air movement may change as the plenum moves. If you do hear movement then whatever's moving is your problem.

[ol550 830]

A little more detail of the year and model would be helpfull. Engine size and mileage may also help in finding common known failures.

Mike

[Michael Bullington 5]

hey mike

2002 Ford Winstar Van (3.8 i think) 6cyl engine auto

107K

Michael

[ol550 830]

Did a little research and the Windstar as many of that brand have trouble with the blend door motors stripping the gears. But, I don't think that is your problem. What I would do next is check the inlet and outlet heater hose temperature. They should be hot and very close to the same temperature when idling with the heater fan on mid speed. If not you have a flow problem. Possibly a clogged heater core. You said it needed flushed... was it full of rust? If so the water pump impeller may be rusted or erroded away. The heater hoses are not that easy to get off but you could try flushing it with a garden hose. Just be carefull if it is below freezing where you do it as it takes a long time to thaw out. One other possible thing is a leaking head gasket or worse a cracked head causing a air lock.

I think you can get to the blend door motor thru the glove box opening. The first thing would be to check the hose temperature and flushing the core.

Let me know if this helps or wants you to trade to a import . Mike

[KyBlue 655]

Hmmm...

You know this probably isnt it...However...I'll make the suggestion anyhow, A couple years back, one of moms friends, said that her 00 blazer wasnt blowing any heat...period. The Prior owner had used some stop leak to fix a small radiator leak...which I had replaced for her not long after she bought the thing. Flushed the Coolant. The Good thing about Stop Leak, is it'll plug up small holes, the bad thing...it cant tell the difference between a small hole...and a small passage in say Oh...A Heater core. I felt the two heater hoses..One was hot...One was Not. I back flushed the heater core. You wouldnt beleive the JUNK that came out.

Something you might wanna check?? Make sure BOTH Heater Hoses are warm/hot to the touch..

You might want to make sure the Shut off valve is all the way OPEN. My older trucks, have a vacuum operated shut off in the heater hose. Turns the Flow of Coolant off, to get colder A/C. That might be partially stuck, and only PART of the hot antifreeze is getting past when your at higher RPMS (Water Pump turning faster, creating more pressure)

[Teddy da Bear 11]

Stone...

Had this same problem in one of my Ford vehicles.

You likely have a thermostat that is rated at too high a temperature.

Go and get a thermostat that is rated at the lowest temperature that

is feasable for your engine. (Ford or an auto store can help you with

that temp. rating).

Your van typically operates at a lower temp than the thermostat you

currently have. And unless the temp of the van runs hotter (like when

in higher rpm's, your thermostat does not open to provide you with

comfortable heat).

Replacing that thermostat with one of a lower temperature is one of

the cheapest and easiest fixes you can do. I would think a thermostat

of a 180 degree rating will serve you best.

Keep us posted!

[Rod(NASNUT) 1]

The first thing I would check would be a vacuum line off or broken at the heater control. As you lower the RPMS it would lose vacuum and let the mixer door open.

[refracman 167]

Have to agree with Rod on this one. Get under the dash and have someone rev it up and listen for a faint whistle. Could be the line is cracked, although is sorta new for a vacume line failure.

[ol550 830]

I hate to dissagree but, the temperature is controlled electrically by a blend door motor. The modes are vaccum operated. If the air flow changes from dash to floor when this happens it is caused by the vaccum actuators but the heat would be the same. Most newer vehicles and I'm fairly sure the Windstar does not have a water valve and only uses the blend door to control inside temperatures. A cooler thermostat will not fix a low heater output temperature as it is what controls engine temperature. Lowering engine temperatures will mess with computer fuel strategies and cause them to run richer.

Not to offend anyone helping . Mike

[Michael Bullington 5]

oh and yes to someone question above...it was full of crap during the flush ,,,had to do it four times!! and it still aint perfect

guys thanks for all the input!! Im going to check out these suggestions, but it doesnt look good for me to fix.. :imstupid: .(can only work on wheel horses,,the small ones..LOL) If I survive one more month...it might be trading time next fall...(I wonder if this will effect my cooling system for summer)...hmmmmm?

[refracman 167]

I googled your problem

heres the link good luck!\

http://www.answerbag.com/q_view/84749

[Rod(NASNUT) 1]

Pull the heater control out and look to see if it has vacuum lines all the doors in the heater box are vacuum controled

[Nick 13]

I think most if not all later model Fords use an electric motor for the heater/AC blend door I do think the heat location control is still vacuum controlled.

This site has pictures an upgrade to the Windstar heater system that they say is a reapir to a common problem.

http://www.heatertreater.net/Windstar%20Listing.html

Edit: After reading how bad the radiator was I still wouldnt 100% rule out a heater core problem. :whistle:

[HorseFixer 2,013]

You guys are pretty good! The Muffler belt on my jeep broke do you have a fix for that! Anyways glad ya got her perkin! :whistle:

[linen beige 15]

Not trying to blast anyone by any means and mean no offense to anyone here, but it looks like Nasnut and I are the only two that actually read the symptoms. A bad thermostat might give similar symptoms but nowhere near instantly. A blocked heater core can keep you from having heat at low speed, but once warm will take a few minutes to cool down when the coolant flow is shut off. It then would take a few minutes to warm back up. Your symptoms are instant. All that points toward a blend door that is not broken, just not working properly. It is most likely directing air flow through the heater core at high rpms, but not allowing air through the core at low rpms. The reasons for it to not work right are most likely that one of the vacuum circuits somewhere in the system are leaking or, if it has an electric actuator, that the actuator is receiving an incorrect signal.

Does the van's heater blower normally come on when you first start the engine? Or does it wait for a signal from the engine that it is up to operating temp? Some vehicles won't run the blower until the engine is up to temp. If your Windstar is equipped with such a feature then the radiator flush you did may have damaged the sensor for that (or some of the dislodged crud blocked it up.)

Having said all this, there is one other possibility that OL550 mentioned could very well be dead on, but I certainly hope not. I cringed when I read what engine you have. The Ford 3.8 litre V-6 was NOTORIOUS for blowing head gaskets or cracking heads, but I was under the impression they had fixed it by the time your van was built. I had one in a '94 Taurus wagon that went through four sets of heads in about 75,000 miles. Whenever one of them would start leaking it would make the heating system do tricks that would fascinate David Copperfield. The dealership mechanic said that was because the widely out of range temperatures caused by the leaking head made the sensors go berserk. On the THIRD warranty try I convinced the Ford dealer to have a machinist to O ring the heads and had no more problems.

[Michael Bullington 5]

guys thanks again for all the input

I really leaning toward the blend door not working or the heater core is all blocked up....

Here are the keys:

when temps are below 30 its really noticeable..and what i mean is your driving down the highway turning 3000 rpm ..heat is blowing nice and hot! As soon as you hit 2000 rpm slowing down the Air Immediately blows ice cold..then kick it 2nd gear to rev the engine back to 300 plus Immediately hot again.

Based on these responces

I think the door to acting up or its just broken and acting stupid...or the heater coil is clogged, but it seems the delay might be longer if it was the heater coil (I think not sure)

P.S I flushed the system trying to fix this problem...it started just all by itself,

Again thank all of you for all this information!! WOW amazing results

I will post what gets this fixed.. :thumbs:

[Nick 13]

Michael, Hope you have an easy and inexpensive fix.

Hey Jim, I think Greg and I mentioned the possibility of a blend door problem first.

Now after armchair mechanicing in a warm house I just need to get myself out in the cold and fix my own problems. Hopefully just need to change another coil on the f250 and then fix the bad rear brake. Right now it vibrates when accelerating or under a load but then shakes ya worse when trying to stop. :whistle:

[linen beige 15]

Hey Jim, I think Greg and I mentioned the possibility of a blend door problem first.

Indeed you did get that posted first Nick. I didn't mean to short you. But in my defense I started typing all the blabber in my first post before y'all got your posts in! (I type real slow.) After I posted and saw y'all's posts I started to edit mine to acknowledge you but got sidetracked.

And mike, I sure do hope this turns out to be a quick, easy, low cost fix as well.