ON A 1998 PLYMOUTH NEON 4 CYLINDER WHEN POURING ANTI FREEZE IN THE RADITOR PORT,WHY DOES THE ANTI FREEZE BUBBLE OUT THEN GUSHES OUT?

Several possible problems, hole in radiator, radiator hose, cracked block or head, missing or damaged freeze-plug...

The radiator would be aged or weak. Never drive the car without original anti freeze coolant. Check the radiator, radiator cap for both functions (compression and vacuum springs from under the radiator cap). Carefully examine the radiator and heater hoses and their clamps. Also carefully examine the cylinder block water lids on both sides for any corrosion. Finally pressure test the coolant system.

It is a normal right hand thread.

check coil pack for resistance with an ohmmeter. if one pack controls two cylinders, the values should b the same. if not replace coil pack

There should be a plug underneath the radiator undo that with a spanner and let it drain into a bucket etc. Replace the plug ( fit new washer if it's torn or damaged ). Pour antifreeze into top of radiator and over flow bottle.

white smoke is caused by-- water or anti-freeze entering cylinder . if in radiator or the overflow tank. it will look like a chocolate milk shake. check on oil dipstick for traces of water or anti-freeze. also, a bad head gasket will let water or anti-freeze in combustion area. head gasket symtoms if bad. Symptom #1: Chronic Engine Overheating
Symptom #2: Significant Drop in Coolant Level Symptom #3: Mixing of Coolant and Engine Oil
Symptom #4: White Smoke from Exhaust Pipe
popping of overflow cap Symptom #6: Air Bubbles in Radiator
Symptom #7: Engine Lacks Power GOOD-DAY!

CHECK FUEL INJECTOR WIRING TO NUMBER 4 INJECTOR,HOOK A TEST LIGHT TO MAKE SURE IT BLINKS WHILE ENGINE RUNNING.THAT WAY YOU WILL KNOW IF PCM FIRING THE FUEL INJECTOR OR FAULT AT THE INJECTOR WIRING OR YOU HAVE INTAKE LEAK LOW COMPRESSION TO THAT CYLINDER BECAUSE OF BAD BURNED OUT VALVE.COMPRESSION TEST TO THAT CYLINDER CAN ALSO HELP.LOOK FOR LOOSE OR WORN DAMAGE ROCKER ARMS IF YOU HAVE A SOHC SINGLE OVER HEAD CAM ENGINE.

check all of your connection son your hoses to make sure that they are not leaking, if that checks out ok, then i would , pull the spark plugs out, 1 at a time, and give the car a compression test to see if any of the cylinders have a low reading, if so , it could very possible be a blown head gasket, also the intake manifold gasket sometimes leak and allows tthe anti freeze to escape into the oil, or into the exhaust port , and will be burned out, therefore creating a white smoke coming from the tail pipe, also when you have the plugs out , look at them to see if they have any anti freeze on them , if so, then this is definitely telling you that a head gasket is leaking or blown.

possible blown head gasket, check the plug colors, and light or tan color is coolant in cylinder

have you changed the fuel filter? Have you changed the ari filter?