Why does ford use coolant in throttle body on 1998 ranger 2.5l engine?

I looked at wiring diagram for your vehicle, 2,5L engine, coolant temp sensor. The diagram shows two wires for the sensor.

they ran coolant lines to the throttle bodies for emission purposes the coolant actually is used to heat the air entering the intake manifold to help preheat your air fuel mixture so less hydrocarbons are made during the combustion cycle however this preheating reduces actual horsepower produced at the flywheel by as much as 10% according to many dyno tests, there really is no proof of any mileage gain or other benefit to this design add , on the older cars and trucks if you bypassed this you had to readjust your timing so you motor would not ping or get a detonation knock under acceleration

I'm not sure my friend, but if you run it very long like that, it will ruin your rings. It's the glucose in the coolant that will finally seize the rings to the cylinder wall. All I can figure is that you've a bad intake manifold gasket that's allowing the coolant in under pressure.

IAC Valve or Solenoid

I would say it has to be on the throttle body
or a spacer under it

Never seen one anywhere else give what it does

is the check engine light on is so have code read 1st-second try cleaning the throttle body where air goes into the engine where the rubber hose attaches clean with a throttle cleaner wipe cleaner out i say this due to the idle air control motor may be dirty,and last you may have a faulty egr valve

check or replace pcv valve. check the hose also. remove and clean the idle air control with carb cleaner ( IAC ). they are usually located on or around the throttle body. check all hoses for a vacuum leak. good-day!

it is located at top of engine at the front hopefully this pic helps

i would change your idle air controle its 60$ and a great start

look around for your throttle body, the pvc valve is usually connected to a rubber tube and connects the engine and throttle body. check the throttle body for a small rubber tube and follow it..if it leads to the engine area and is connected by i believe a "L" shaped plastic piece, thats your pvc valve

FIRST OF ALL YOU HAVE TO DRAIN SOME COOLANT.JUST ENOUGH SO COOLANT WONT FLOW ALL OVER ENGINE.AND COOLANT TO EXPENSIVE ON THE GROUND.TO GET TO THERMOSTAT.YOU HAVE TO DISCONNECT CONNECTORS TO MAF EGR IDLE SPEED CONTROL AND IAT SENSOR.. REMOVE THROTTLE AND SHIFT CABLES FROM BRACKET.REMOVE AIR FILTER ASSEMBLY WITH MASS AIR FLOW SENSOR.REMOVE BOTTOM PORTION OF AIR FILTER HOUSING.REMOVE COOLANT HOSES FROM THROTTLE BODY.THEN REMOVE THROTTLE BODY ASSEMBLY.YOU HAVE TO DISCONNECT SMALL COOLANT HOSE TOP WATER PUMP.REMOVE SMALL BOLT THAT HOLDS METAL COOLANT LINE TO WATER PUMP.THIS LINE HAS TO BE MOVE JUST ENOUGH SO YOU CAN REMOVE THROTTLE BODY.ONCE THROTTLE BODY OUT THE WAY YOU CAN REMOVE THERMOSTAT.BESURE WHEN YOU PUT EVERYTHING BACK TOGETHER.REPLACE THROTTLE GASKET AND THE COOLANT HOSES COME OFF THROTTLE BODY BESURE TO USE OLD COOLANT HOSES MEASUREMENTS FOR NEW HOSES MEASUREMENTS MAKE SURE YOU BUY THE CURVE HOSE FOR THROTTLE BODY. DONT TRY TO USE STRAIGHT HOSE IT WILL KINK AND CAUSE NO COOLANT FLOW.WHEN YOU ARE DONE.FILL COOLANT BACK TO CORRECT LEVEL AND BLEED COOLANT SYSTEM.