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Engine temp wont go up

10-28-2009, 06:49 PM
My 96, 3.0 Windstar seems to run cold. Temp gauge does not go above the "c" mark. The fans are running at start of a cold engine. In replaced the ECT sensor after breaking it trying to check it. I get just a little over 4v on the sensor. I also noticed while revving up the cold engine the radiator hose going to thermostat would collapse while revving engine. I did not think thermostat would run the fans, since it is mechanical. Any suggestions from here? I'm thinking of going ahead and replace thermostat and flushing radiator as there is a lot of brown residue on radiator cap. But the fans should not run on start up of a cold engine.

10-28-2009, 08:02 PM
The radiator fans will run if the climate control is set in any postion that will activate the A/C.
This will include any setting that includes Defrost.
My '96 has to be set at VENT or off to not activate the A/C.

The top radiator hose should NOT it factory original?....maybe it has gotten too soft.

It is possible that the thermostat is stuck......or that the sending unit for the temperature gauge is defective....or the electrical connection to the temperature sending unit is defective.

You have 2 temperature sensors...... 1 for the PCM (computer) and 1 for the gauge.
I do not know how they are located on the 3.0L motor.
I understand that I have them labeled backwards on my picture of them on my 3.8L motor.
On the 3.8L motor, they are both located very close to the thermostat.....right next to each other.
The sensor for the temperature gauge ONLY has the gauge connected to it.

The one for the PCM is used to determine when to turn the radiator fans ON at low speed or high speed (higher temperature).
The PCM sends signals to the CCRM (Constant Control Relay Module) to activate the low speed fan relay or the 2 high speed fan relays.

Brown residue.....good idea to flush the radiator and install new coolant.
I know that with the 3.8L motor that it can be tough getting all the air 'burped' out of the system.
So.....if the temperature climbs to high...just shut the motor off....and let it cool......
You may have to add some more coolant once the motor cools off.

Use distilled water.
If you use a concentrated coolant (not the 50/50 "ready to use")....what I do is take the capacity of the complete cooling system.......divide by 2.......and once I drain as much out as I can.....I add the amount of pure coolant to equal just over 1/2 of the total capacity.....then (if you have room) top off with distilled water.
The will not be able to drain all the water out......and if you add a 50/50 mix to will have too weak of a coolant mixture.

If you use tap water to flush the a final flush with distilled water so that the water that remains in the system will be the distilled water.

For coolant, your '96 calls for "traditional" green, which you can get in the Motorcraft brand or Zerex Original Green (and a few other brands).
You have to hunt for Traditional Green now.......harder to find than it used to be.
The yellow jug of Prestone is a long life, silicate/phosphate free product.....not on the list for the Windstar...although it may be OK......
If the jug says that it is "Silicate Free", it is definately NOT Traditional Green (or G-05).
I have Zerex G-05 in my '96 3.8L......which the factory calls for traditional green for......the G-05 is close, but not the same....(newer vehicles call for the G-05)......I am thinking that it is an is a LONG LIFE coolant that HAS silicate.
G-05 is another coolant that you have to hunt for.....if the label does not say that it is G-05, it is NOT.....regardless of what the auto part store clerk says.
G-05 coolant is also available under the Motorcraft Gold label.

Some coolant information on the Zerex site.

10-28-2009, 10:25 PM
I don't think it's your ECT sensor that is deffective.
Do your heater work after 2 miles of driving?
You may have air trapped in your coolant system. To get rid of it, when engine is cold, remove the pressure cap. Coolant should be at top. Turn on your engine, you may see air bubles on the surface. Let engine runs until it stops bubling, then install the pressure cap back.

Because the hose collapses, maybe you need to check the thermostat if it's stuck open.

When temp is at cold mark (100F) touch this hose. If it's warm as a person, it's definitively the thermos.

10-30-2009, 11:18 AM
Wow!! Thats a lot of good info. Thanks Guys. I wasn't aware of the green stuff requirment and have allways used tap water to flush system. I guess i'll be getting distilled for final flush and use some 50/50.

10-30-2009, 04:41 PM
I suggest you to repair your cooling system problem BEFORE replacing the coolant.
So you'll not have to do it twice.
About the antifreeze type, if it should be also compatible with aluminium and be low on silicate. But not free, like Wiswind said. Autolab is a a good antifreeze brand.
You need to weigh the antifreeze's final solution to be sure that you have the correct weight.

11-01-2009, 09:21 PM
I just thought about something when I check a Dodge Stratus. If the hose collapses, maybe this hose is not enough thick and don't resist to the depression vacuum. Press on it to check its thickness. Or you've air in it, like we said. But normally this should cause the engine to overheat, not overcool. If it's too soft, you should replace it anyway.

01-11-2010, 06:56 PM
A family asked me to replace the Thermostat in a 99 windstar could show me where to find it? I have no manual to show me.

01-11-2010, 07:14 PM
A family asked me to replace the Thermostat in a 99 windstar could show me where to find it? I have no manual to show me.

The thermostat is on the driver side of the engine, where the upper radiator hose is attached to the engine. You should remove the 2 bolts on the housing.

01-11-2010, 07:16 PM
got any photos? sounds like an easy fix.

01-11-2010, 07:27 PM
Here's it.

01-11-2010, 08:33 PM
You are pretty much cannot see it....
You need to remove the big flex hose that goes from the throttle body to the air filter box/bullet.
Then you will be able to see it.
Just follow the upper radiator where it connects to the motor.....that is the thermostat housing.
Here is a link to a picture of the thermostat and the housing for my '96 3.8L.....yours should be similar.
Note the tab on the thermostat and the notch in the housing....and the orientaion of the weep hole in the thermostat.

01-12-2010, 10:02 AM
TIP: I changed those bolts to studs and nuts. Works a lot better for me when trying to seat the thermostat and cover properly.
... also, use only petroleum jelly for lubricating the gasket. Makes later removal much easier.

northern piper
01-12-2010, 11:40 AM
when you changed to studs and nuts 12ounce did you just locktite the studs in or is there something more funky that you did?


01-12-2010, 01:48 PM
I did use Permatex LocTite on the stud threads ... mainly to keep moisture out and corrosion at bay. Washers under the nuts.

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