Hey at least it ain't politics !
Our '99 Toyota 4Runner has a heater problem that's driving me (more) nuts . The heater apparently isn't getting enough coolant flow , and isn't putting out enough heat . I've checked all the hoses from the motor thru the valve and heater core and back to the engine , hoses are OK and the core isn't plugged . I've also flushed the entire system , all hoses and the core and associated plumbing . After flushing it out it'll do OK for a short time then it's back to not enough heat . Pertinent info - the water control valve is cable operated from the dash along with the gating for airflow in the heater box . I don't think there's a t-stat type device in there for temp control , but if there is one and it's malfing that might explain it . The coolant level is up , and circulating when observed in the radiator . This has really got me stumped , and the wife is getting pretty hot herself about it - we're getting into the cold season here and she's the main driver .