Chrysler

First a caution: NEVER ever think of releasing a radiator - coolant cap when the engine is hot, or even warm!!!

Burping: In order to what is sometimes referred to as 'burping' the cooling system - getting a big air bubble out of the closed cooling system, and IF the car has a radiator cap,you will actually need to have the car running with the cap off.

1. During the initial fill, fill the coolant reservoir bottle to the top of the cold fill range.
2. Set the temperature blend selector to the full warm position and the fan motor control to high for the front and rear heaters
3. Start the vehicle with the reservoir cap off and allow to idle until the thermostat opens

   NOTE: the coolant level will drop quite a bit when the thermostat opens - that's most of the air bubble in the system being driven to the top of radiator and escaping. Without the air, there's more room for coolant.

4. Top off the coolant in the reservoir bottle to the top of the cold fill range,
5. Install and tighten the reservoir cap.
6. Increase the engine rpms to 3,000 for 15 seconds, and then return to idle for one minute.
7. Repeat the previous step four times or until heat is coming from the rear unit while the vehicle is idling.
8. Allow the vehicle to cool and top off the coolant in the reservoir to the cold fill range.

Note: if you find the heater going cool or cold when idling, that's a good indicator you might have to burp the system again. Equally likely just adding more coolant to the overflow reservoir will suffice too.

Did I mention to NEVER ever think of releasing a radiator cap when the engine is hot, or even warm? !!!

This is the best ever clue to burp the system and I still had problems with air bubbles. I finally got it to quit blowing cold air due to air in the cooling system.

1 - Do it like the person above advises

2- Open up the radiator cap while it is still cold start the motor and when you see the coolant flowing after the thermostat opens. stick a long funnel into the filler neck because the fluid is going to overflow in a hurry.

3- The long funnel is going to capture the fluid and when it goes up your funnel then it's going to drain back into the radiator you may loose some fluid due to overflowing the funnel because it's going to belch about a half of a gallon or more - so be prepared to immediately pour some more antifreeze back down the funnel to keep the radiator full and keep the air out when the water pump moves the fluid back into the motor. At all costs keep replenishing the fluid when it belches air and fluid out of the radiator into your funnel or air will get back into the motor and will defeat your attempt to keep the air out.

4- You have to do this 2 times to rid the system of air before it works so wait for the thermostat to open again and repeat pouring fluid back into the system. Don't piddle around while doing this because once the water pump sucks air in the radiator because your not pouring the fluid back in fast enough and your not going to belch it.

Have a friend to help you get ready to pour antifreeze back into the radiator when it cycles. I had a catch pan under the car to catch the spilled fluid and reused it to pour it back in after the first belch so your friend can put that into a container to get ready to fill the funnel into the radiator again on the second belch.

5- no matter what - DON'T let the radiator level get low at any given time!!! keep pouring in the fluid fast as you can to keep the radiator completely full so it will have no air in it when the thermostat opens and cycles fluid through the water pump.

6- Wear safety glasses because fluid will spill and hit the engine belts while it's running and it will fling fluid everywhere.

It took me several attempts experimenting how to purge the system and this way I found definitely works for me and never had a problem since. I worked for Ford as a line mechanic for several years and this windstar is the meanest system I've ever purged. So if you ever have to change your antifreeze and drain the radiator and engine block this is the way I found to purge the system of air successfully... Thanks to the fellow above on his advise it helped out a lot.

I'm going to give you some more hint's that lead to this problem.

Look at the bottom side of your radiator cap you'll see a rubber washer mounted under the spring cap. If the rubber gets larger than the cup it's mounted on it will seal against the neck and won't let excess pressure escape from the cooling system effectively nor will it let fluid return into the radiator from the reseroir - so you'll need to buy a new one but WATCH-OUT even the parts stores will sell you a new one with the rubber sticking past the cup it's mounted on (The ones made in Mexico are the bad ones to buy) Just make sure the rubber is a little smaller than the circumference of the cup it's mounted to and you'll be alright... This applies to all vehicles and equipment new and old.

I've found parking your windstar on a kind of a steep hill with the drivers side higher than the passenger side will force the air in the heater core and the engine to release air in the system through the thermostat a little quicker and is more effective in purging the system...