The thing that causes the hoot noise is your idle air controler valve. If you replace it you will get rid of the noise. Ford prices the part at $127.00, but you can get it from auto zone or advanced auto for around $50.00. It takes about 30 seconds to change and it is located directly on top of the engine. It is as easy as opening the hood and changing the part. Also on an explorer you might want to watch out for the hood hydrolic arms giving out. Those are only about $20.00 to replace from auto zone or advanced auto, but again ford charges $89.00.
idle air control valve
The Ford Explorer uses an idle speed control valve that allows air to flow thru the idle air passage inside the intake manifold. When this air passage gets clogged up with carbon or grime it restricts the passage & the result is a loud humming / moaning noise. The repair is to remove idle speed control valve & spray carburetor cleaner or intake cleaner thru air passages inside intake manifold & clean or replace idle speed control valve.
Out of time.
Isc motor is stuck or sticking causing a "blowing over bottle" effect in the intake tract.
back of the intake manifold, middleof the engine. lets gasses from exhaust back into the intake. will be a tube coming off it to the passenger side going to the exhaust manifold
Mine does the same thing.. and im pretty sure that it is the auxiliary fan
follow the top radiator hose to the front of the engine. Right under the intake manifold answer Thermostats are located in the engine intake of any ford explorer.
the intake manifold is what takes air coming from the intake and directs it to each intake valve in each cylinder
The EGR valve on a 93 explorer is on the PASSANGER side of the motor just to the right of the oil fill stem coming off the engine. Youll notice the metal hose coming off the top of the valve. Theres 2 bolts, one on the left and one on the right holding it onto the intake manifold.
whistling noise from engine will be caused by a leaky gasket,sucking air. this is usually the intake manifold gasket
it is in the air intake canister
Possibly the EGR system ... try squeezing the hose from the air intake (plastic thing that says SOHC on it) that goes to the rear of the engine (about 1" dia.). If it stops, the humming might be a sticky EGR valve.