142,000 on the clock, belt was change at 90,000. no heating problem for know, just looking ahead before its to late, someone said the water pump and idler pulley should have been change at about 125,000 to be safe. there is no water leaking at pump. at 65-70 its at 190 DEG. no load, is it a good thing to change these items now. how many miles should I change these parts. radiator is clean.