Cooling system bleeder valve

Where is the cooling system bleeder valve on a 1999 Mercury Villager? The bleeder on the engine, not at the radiator.

Are you looking for the drain valve? You won’t have one on the engine. Many cars don’t have one on the radiator either. I always drain the system by disconnecting the lower radiator hose.

No, I’m looking for the air bleed valve. I have air trapped in the system , which is causing low heat output from the heater. Fluid level is fine and the thermostat appears to be working fine also, the gauge stays right in the middle after warm up.

Many vehicles do not have them including my '99 4.6L Merc. I don’t know about the Villager specifically. If it has a degas bottle and you have the original-style thermostat with a jiggle valve you should not have air in the system. You could try opening the uppermost hose connection a little.

You are hoping it is air trapped in the system that is causing low heat as there is no test for this, just a system bleed any way you can and then check the results.

If you have one it will be in the highest point in the system.

Many cars don’t have them.

It’s called the engine air relief hole. I have an illustration but it isn’t very clear where it is located. I would look on the driver side of the engine for a bolt that doesn’t appear to hold anything down.

The procedure for removing air is quite extensive, I can post the procedure but I can’t post the illustrations. This is from ALLDATA…

NOTE: When filler neck is full, gently move upper radiator hose up and down while filling until coolant no longer lowers in the filler neck. Slowly fill the radiator with the correct 50/50 mixture of Premium Cooling System Fluid E2FZ-19549-AA or equivalent meeting Ford specification ESE-M97B44-A until coolant fills the radiator filler neck.
Insert a wire under the negative pressure valve of the radiator cap.
Install the radiator cap.
Disconnect the coolant expansion tank tube from the radiator.
Hang a one gallon modified bottle above the engine air relief hole and connect a suitable tube from it to the coolant expansion tank tube port on the radiator.
Clamp the tube to prevent coolant flow though the tube and fill the modified bottle with the correct 50/50 mixture of Premium Cooling System Fluid E2FZ-19549-AA or equivalent meeting Ford specification ESE-M97B44-A and water.
Unclamp the tube used with the modified bottle and allow coolant to flow until coolant comes out of the engine air relief hole, then reclamp tube.
Install the engine air relief plug.
Raise and support the vehicle using a suitable supporting device.(Just the front end,approx. 22 inches)
Set the heater controls to full warm and blower to high.
Unclamp the tube used with the modified bottle.
Start the engine and maintain 1500 RPM until the cooling fan turns on.
Turn the engine off and let the engine cool off completely.
Clamp the tube used with the modified bottle.
Remove the modified one gallon bottle and tube.
Connect the coolant expansion tank tube to the radiator.
WARNING: Never remove the radiator cap under any conditions while the engine is operating. Failure to follow these instructions could result in damage to the cooling system or engine and/or personal injury. To avoid having scalding hot coolant or steam blow out of the radiator use extreme care when removing the radiator cap from a hot radiator. Wait until the engine has cooled, then wrap a thick cloth around the radiator cap and turn it slowly to the first stop. Step back while the pressure is released from the cooling system. When it is certain all the pressure has been released, press down on the cap (still with a cloth), turn and remove. Allow the engine to cool and remove the radiator cap.
Remove the wire from the radiator cap.
Completely fill the radiator with the correct 50/50 mixture of Premium Cooling System Fluid E2FZ-19549-AA or equivalent meeting Ford specification ESE-M97B41A and water.
Fill the coolant expansion tank to the MAX mark.
Install the radiator cap.

Thanks. I have done this on my 97’ villager before but of course they moved the plug on the 99’ and for the life of me I could not find it.

Whitey, very complete instructions, you are going to spoil our readers.

Sorry but it’s Willey

As much as I would like to, I can’t take the credit.

In what way is this “modified bottle” supposed to be modified? Obviously the modification has to involve being able to put a hose on it. How does one do this “modification”? Thanks!