4runner 2000 4 cylinder. radiator cap interior components came apart while driving the car, antifreeze leaked out through the plastic reservoir, the engine overheated until check engine light came on and I stopped the car. I refilled with water after cooling down the engine and went home about 4 miles away, now the engine is overheating, I replaced the radiator cap, replaced the thermostat, flushed the radiator, removed radiator hoses and tried to flush the engine water jacket with garden hose trying to remove any loosen radiator cap components, put everything back together and still is overheating. No leaks detected. Is it possible that there are radiator cap components and there is a blockage somewhere in the engine.
I filled up radiator with water all the way to the top trying to see bubbles or air coming out of the radiator while warming up the engine and nothing. I noticed that the car overheats while driving but cools down slowly when idle, does the same with or with out thermostat.
Water pump seems to be working OK, belts are tight, fan clutch seems to be OK.
What’s the problem, how to fix it?