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95 Windstar- radiator back pressure?

01-30-2007, 01:58 AM
Hi all. This is the same Windstar I had tranny problems with (fixed, will update that post later.) We just got it back from the trans shop today, and noticed the temp guage was sitting on the high side of "normal." It would fluctuate between the O/R, and the N, in NORMAL. Occasionaly, it would kick down suddenly to the R/M.

When we stopped, we noticed the tell tale signs... steam from under hood. Checked it out, could not find the leak at the time. Topped off radiator, went for a short 30 mile drive. The van sat for 2 hours, and we headed home- but the heater no longer worked! The blower fan works fine; all settings for air direction work fine. There is no "clicking" from under the ash tray.

I got it home, read through all of the related threads here that I could find. Checked coolant level; low. Topped it off with 1 GALLON of hot water (it is 20 degrees outside here.) Ran it for a while, seemed fine, but still no heat from heater. I replaced the cap (had been running it w/o cap), and shortly afterwards, it started filling the resevoir tank.

Just in case it was an air lock as someone suggested elsewhere, I turned it off, let it cool, then started over. This time, I noticed that it was again a gallon low. Topped it off, watched it... and suddenly it started literally vomiting mass quantities of fluid out of the spout! (still no heat inside.)

While it was running, I crawled under the front, and grabbed the main hose at the bottom- it was barely warm... and I could easily pinch the hose shut with two fingers.

After reading much, am I correct in understanding that it is either my thermostat, water pump, or blown head gasket? If so, will Liquid Copper fix it?

Does anyone have a picture of a water pump in place for this?

01-30-2007, 12:58 PM
The heater core is the first place water/coolant goes from the water pump. With no heat the first thought is typically low coolant. From there you either have a water pump issue, or a blocked heater core.
As to your lower hose: I believe it would be "loose" until the thermostat opened up and coolant began to flow through the radiator (assuming normal system ops). Perhaps that event had not yet occured or is not.
Do you have a separate rear heat system? If so, is there any heat there? If installed it is a separate heater core, and if it had heat it might point to a blocked front core.
As to water pump pictures, here is a link for autozone for water pump replacement. Might help
You could be losing coolant at the water pump. Mine ('96 3.8L) was leaking significantly around the water pump shaft (seal failed). Replacing it is your only reasonable course if that is the case. If it is leaking there, coolant can easily find itself on the exhaust manifold from that point and "steam".

Hope some of that is helpful. Others will add I'm sure.

01-30-2007, 03:31 PM
Thanks for the information. **EDIT***

I found the flow path information here:

So it seems that a non-opening thermostat WOULD cause back pressure through the system, which would blow out the only available hole/path- through the bottom radiator hose, then up and out through the cap... correct? This would explain why it does not start tossing water until after it has run for 5-10 minutes... Also, if the thermostat is blocking all hot water, then it never has a chance to enter the heater core (as heated water)- so the water pump IS only pumping cold water into the heater core....

Maybe? lol

01-30-2007, 04:56 PM
Well, sort of.:)
The water flow on a cold engine is "closed loop" basically through the heater core, block/heads etc. only. When the thermo opens up (about 200 degrees) the water can then leave the block/head go out to the radiator via the top hose, cool and then back into the system via the bottom hose and water pump. Depending on outside air temp and engine load, I suppose you could have a situation where the thermo never opens. Anyway, heat availability "should" be independent of thermo position.
With that said, a non opening thermostat should produce a hot engine and fluid back up/ overflow. The only thing is, I would expect heat availability in that situation. That said, you may have a combination of problems: a fair amount of air in the system and a stuck thermostat. I had to work at getting the air out of my system after recent work. A thermostat change is certainly no big deal. Be sure and get a new gasket with the thermostat.

01-30-2007, 05:27 PM
What is odd, is that every time the dash gauge temp drops to the 1/2 way point, the heat works... but for no more than a minute before it starts getting cool again. It is almost like an intermittent blockage... I belive, but have not verified, if the temp drops on the guage match the activation of the radiator cooling fans.

Oh, and outside temp is 20 degrees, with no load on engine (ie, idle.)

01-30-2007, 05:34 PM
What is odd, is that every time the dash gauge temp drops to the 1/2 way point, the heat works... but for no more than a minute before it starts getting cool again. It is almost like an intermittent blockage... I belive, but have not verified, if the temp drops on the guage match the activation of the radiator cooling fans.

Wow. Weird stuff. As it is cheap and easy, I would change out the thermostat as it may be opening /closing at odd temps/intervals and fill and remove the air from the system to see where you are at. If you have the 3.8L I believe the 195 degree is the correct choice.

01-30-2007, 06:00 PM
I have also found that things do not work well.....fluctuating temp. etc......if there is air in the system.

Having to add a gallon of water would indicate that a lot of coolant has been lost.......someplace.

It IS normal for the water level to rise as the engine warms up.....and when the cap is on, the coolant will go into the overflow bottle.
Then when the engine / radiator coolant cools down....the coolant is sucked back into the system.....from the overflow bottle.

Now, if you have a leak........coolant will go out through the leak.....on the warm cycle.....and then.....air can be drawn in on the cool cycle.....which will then cause all the problems of a air pocket in the system.

The water will be flowing through the "bypass" tube, through the heater hose that goes out on the driver's side.....through the heater core.....then back into the engine on the passenger side.

A blocked thermostat will not interrupt the flow of coolant through the engine, or heater.

When the thermostat opens, the coolant will flow OUT to the radiator through the TOP radiator hose.......into the top, driver's side of the radiator....
There is a plastic "tank" on each side of the radiator......and it is hollow from top to bottom.
The water will flow through the alluminum radiator the plastic tank on the passenger side.
Then the coolest water will flow down to the bottom radiator hose....and back into the engine.

Take note that if you have air conditioning, the fins that you see on the front of the radiator are the air conditioner condensor coils.....not the radiator fins.

So.....that said.....the bottom radiator hose will be the last thing to get warm.

I am guessing that you have a leak.....which is causing you to loose coolant.....and then air is being drawn into the system......which is going to cause things to not work well......especially if air is at the water it will not move air enough to push water.....

I would say to look for steam in the exhaust to see if it is a head gasket or lower intake manifold gasket.....but at 20 degrees outside.....there will be a good amount of steam and water dripping out of a good engine.....and the mind can play tricks (been there also) if you have green could see if you have green water dripping out the tail pipe.....
Again, 1 gallon is a you should be able to locate the leak.....

FIRST place I would look.....would be one of the heater hoses......or that pesky little elbow (if the '95 has it) is a "U" shapped elbow....only about 6" long......a metal tube comes out of the water pump.....pointing toward the firewall.....and then there is a small hose that connects to it.....that turns back toward the radiator.....and connects to the water bypass tube.
I have a picture of the water bypass tube posted in my pictures.....
But...again......they used a different intake manifold on the 95 than on any of the other years......but really give those heater / bypass hoses a good it is much cheaper and easier than some of the other options.

01-30-2007, 06:28 PM
Thanks, both of ya. The only place that I can find steam where it should not be, is on the passenger side of the radiator... Recently had similar with my Chevy PU, and there it was a pinhole, so looked for same. I could not find any actual leakage, so just let the motor run... It seems that it eventually blows out the radiator cap itself.

I realize the standard flow in/out of the overflow bottle, in that it is normal. What was odd, is that with the cap off, it was not an "even flow"; it litterally had a rythmic pulse to gushes of fluid coming out the top- identical to someone that has had WAY too much to drink and goes projectile... That is why I suspected a blockage of some sort.

With the heater OFF, no water should go through the heater core anyway correct? If so, having the heater OFF, if the same thing happens with the water push out the cap, then it should not be a blocked heater core...?

Incidentally, I had to move the van to get our Explorer out just now, and after sitting all night/day, I topped off just a 1/2 gallon, started right up, and heater produced heat after only about 3 minutes... gradually getting warmer in the cab even. Not enough time to test it thoroughly, but... odd nonetheless.

Does Liquid Copper hurt anything if the head gasket or head is NOT cracked, and you use it anyway?

I'm broke till the 1st anyway, so just spending the time till then troubleshooting...

01-30-2007, 07:04 PM
Water ALWAYS flows through the heater core when the engine is running.
The temp control causes a electric motor to move a blend door to determine how much air will go over the hot heater core.

The control that you select defrost, heat, A/C, etc causes vaccum driven control of where the air goes.....with defrost being the default in case the vaccum source is lost (there is a resevoir that holds vaccum for the diverter control when the engine is off).

I read the label on the bottle of Bar's product for head gasket sealing (don't remember for sure if it was called liquid copper or not...but sounds right), give it a good reading.....they tell you to flush all coolant out of the system.....only pure water......put in the drain completely....and wait a long time.

If you had steam from the radiator....and you are sure that it was not from running down from the radiator cap.....or the hose connection from the overflow bottle....then I'll bet that you found your problem.
I read that there can be an issue where the plastic tank to radiator connection can leak......does not take much of a leak to cause the problems you have.

You will notice it with the radiator cap ON......such that it builds up pressure.
And....if it is such that you can get a little air into the can take your overflow bottle right out of the you can be low on coolant....with a full overflow bottle......

So.....I would fill things up.....overflow bottle also.....and put the radiator cap on.....
Then start the engine....and let it idle......keep a really good, constant, watch on the temperature gauge....and shut it OFF if it gets up to that you do not damage the engine........
Then, watch what it has shot coolant out as you can expect steam to come up if the radiator becomes it will be just drying off.......
Once the temperature is up into the warm, normal area...........It will drop down some when the thermostat opens......
But....once things are warmed up....and there is pressure in the can shut the engine down.....and then look for any signs of leakage......steam rising that has a hiss to go with a sign of leakage.

01-31-2007, 09:47 AM
I have not found it to be leaking anywhere OTHER than the cap... With the exception of when I first found it was leaking.

When this all started, it looked like a simple case of the hose from the cap tube to the overflow bottle was leaking- at the nipple to the cap tube, due to lack of a hose clamp (the rubber hose slide easily on/off the nipple.) I put a hose clamp on that connection, and thats when it started pushing out through the actual cap, and higher than normal engine temp started... There is no sign of leak-hiss, or active leak; the only steam in the engine, is burn off steam, when it pushes out past the cap, lands on the fan belt, and then paints the engine compartment pale green...

So the possibility remains that this is just air trapped inside the system from the first leakage? Is there a better way to work the air out, other than standard fill while running?

01-31-2007, 10:01 PM
I would try changing the thermostat. Your main water flow back to the radiator is through the top radiator hose. When the system is pressurized and the thermostat opened the hose should be firm and hot. If the thermostat is closed the engine will generally overheat. When adding fluid keep monitoring the fluid level and make sure the thermostat is open. If it is closed the engine will not allow large amounts of fluid back to the radiator and cause air to remain in the system. I am 95% certain your thermostat is the cullprit. I have had this happen many a time on different vehicles but never he Windstar. If the thermostat is open you should be able to see the water circulating in the system through the open cap. Also remember if its not pressurized if the cap were bad you could get similar results but generally the fluid would leak through the cap. If you were loosing a gallon of water that fast you would surely notice it or it would steem like crazy.

01-31-2007, 10:25 PM
Knock on wood... but up to including a 2 mile test drive today, I think I have it fixed. IF that is true:

The problem was entirely the air trapped in the system. Caused by loose overflow hose (between cap neck and overflow tank.)

I put a hose clamp on said hose, but was shocked to see the amount of fluid that kicked out of the open cap when the thermostat opened up, and fluid started flowing freely throughout the system. (The point mentioned in advice above, about how/when the overflow tank comes into play.)

Pitting your advice against my lack of common sense, I closed the cap, and began monitoring fluid level/air bubbles through the overflow tank's open cap instead.

Once the bubbles stopped, full heat capability returned to the cab as well. I shut it off, adjusted the fluid level (too much had gotten into the system by this time.) Waited an hour, then drove it two miles... and everything still worked.

Temperature guage remains in the bottom 1/4 of the "normal" range.

I will be taking it to town tomorrow (payday) so it will get a good 60 mile round trip test drive.

Windstar: $4000
Rebuilt Tranny: $2000
Advice here: Priceless.

***2/1/07 EDIT***

Stick a fork in it, she's done!

02-02-2007, 06:01 PM more bit of you mentioned that coolant got onto your serpentine belt.....I would buy a new one.
The coolant onto the belt can cause it to soften up, slip, and eventually fail.
Is better to change it on your schedule than to have to deal with it when it fails.

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