95 Windstar Temp Gage Fluctuating

[Dngrsone]

The cooling system on the WIndstar is a closed-loop, pressurized system. Your radiator cap should hold the pressure in the system to 16psi or so, if you run without a cap on, then you won't have enough coolant. So your first priority is to make sure you have no air bubbles... do your little procedure there, then fill the radiator all the way up, and fill the overflow bucket to the line.

Take the van out for a short drive, at least long enoughfor the thermostat to open up, then wait for the engine to cool and check the overflow reservoir, fioll as necessary.

The heater is an integral part of the cooling system, so there is always engine coolant running through there. The environmental controls determine how much air will pass through the heater coils on their way into the cabin for heating/cooling.

IF you still have problems after all the bubbles are gone, then perhaps you do have a pump issue.

[kusawakate]

Update on the windstar... Well, I'm not worrying about the temp gage at this point. The whole exhaust system from the rear of the motor to the muffler fell out while I was driving down the highway. I'm just soooo glad I had the mind to be a AAA member. Towed it back to the car lot where I bought it, and they will have to work on it now, just to make it driveable. LOLOL All I can say right now is that I'm glad I have a good sense of ha ha.

[2k3windstar]

Not in response to the cooling problems, but the EGR code. I had a '95 Windstar. The EGR code on mine was due to the flow sensor going bad, not the EGR valve. The sensor was $40'ish at AutoZone. There is a small orifice in the EGR line. The sensor measures the pressure drop across this orifice. More flow, more pressure. Hoses bring the pressure signal to the sensor, mounted on the driver's side of the manifold. The computer adjusts the EGR valve to get a certain amount of EGR flow. Label the hoses before removing them. If the hoses are on backwards, it will look like no EGR flow.

A quick test for EGR is to put a vaccum signal on the EGR valve with the engine at idle. If the engine stumbles, or nearly dies, with vacuum going to the EGR valve, then the valve is opening and allowing exhaust gas to flow.

Hope you work out the cooling issues.

[davwha]

I had a similar problem with a 3.0L ford ranger. It turned out to be a leaking head gasket between the intake and coolant ports of one of the cylinder heads. This let exaust gas into to the cooling system (air pockets) and some oil mixed with the exaust gas caused the coolant to turn brown and oily. My temperature gauge would run hot when idle just like yours and the heat would suddenly run cold at times (because of the air pockets in the cooling system). Also the exaust gases in the cooling system greatly increases pressure of the cooling system which is why your hoses burst and why when you leave the radiator cap off the system runs cool because the excess pressure is allowed to excape. Have your cooling system pressure checked to check for a head gasket leak now. If you wait too late, you might risk cracking the cylinder head.

[kusawakate]

Originally Posted by 2k3windstar

Not in response to the cooling problems, but the EGR code. I had a '95 Windstar. The EGR code on mine was due to the flow sensor going bad, not the EGR valve. The sensor was $40'ish at AutoZone. There is a small orifice in the EGR line. The sensor measures the pressure drop across this orifice. More flow, more pressure. Hoses bring the pressure signal to the sensor, mounted on the driver's side of the manifold. The computer adjusts the EGR valve to get a certain amount of EGR flow. Label the hoses before removing them. If the hoses are on backwards, it will look like no EGR flow.

A quick test for EGR is to put a vaccum signal on the EGR valve with the engine at idle. If the engine stumbles, or nearly dies, with vacuum going to the EGR valve, then the valve is opening and allowing exhaust gas to flow.

Hope you work out the cooling issues.

Bingo! This is great info, and now that the van is at the shop with the exhaust system dragging on the floor, I will give this info to the mechanic. Thank you, thank you, thank you.

[kusawakate]

Originally Posted by davwha

I had a similar problem with a 3.0L ford ranger. It turned out to be a leaking head gasket between the intake and coolant ports of one of the cylinder heads. This let exaust gas into to the cooling system (air pockets) and some oil mixed with the exaust gas caused the coolant to turn brown and oily. My temperature gauge would run hot when idle just like yours and the heat would suddenly run cold at times (because of the air pockets in the cooling system). Also the exaust gases in the cooling system greatly increases pressure of the cooling system which is why your hoses burst and why when you leave the radiator cap off the system runs cool because the excess pressure is allowed to excape. Have your cooling system pressure checked to check for a head gasket leak now. If you wait too late, you might risk cracking the cylinder head.

Bingo Again! This is also great info, and again, now that the van is at the shop with the exhaust system dragging on the floor, I will give this info to the mechanic too. Thank you, thank you, thank you.

Everyone is great here! Thanks so much all!