AtoZ

Vehicle: 95 accord, vtec, at, 160k

literally. while I was back flushing my cooling system thru the upper rad hose trying to clean out the heater core thru an open inlet hose. i wondered why the water was flowing thru the valve when it was in the off position. i took the heater valve off and there was no valve inside of the part. the white colored valve inside curled up somewhat as if melted, and it also looked as if it corroded or maybe had broken off in another spot. the damage looked old, but im still not sure when or what happened. since the actual valve inside is larger than the hose tubes going into the valve, it couldnt fit thru its inlet or outlet tubes on the body of the valve. i didnt see any sharp broken off jagged edges to indicate breakage, but perhaps it dint break but melted. however, those valves are designed to handle hot coolant so it is hard to figure what happened.

right before i discovered the missing valve i had been cleaning the cooling system for grease, oil, and rust with two cleaning solutions. but neither of them would destroy the valve. ive left these same cleaners in plastic buckets for months without any problems. in fact, plastic or rubber containers are what you have to use. all they would have done is cleaned the plastic and rubber parts if anything.

P_Adams

I'm at a loss myself.
If it had been overheated that badly, you'd see more stuff melted than just the guts of the Hot Water Control valve.
In addition, I can't think of a chemical which would attack it and not ruin other stuff as well.
Hopefully none of it circulated into the heater core or you'll be dealing with a whole different set of issues.

P

AtoZ

a local mechanic told me that steam could do that. oddly the car does not overheat and seems to run fine. doesn't seen to have any head gasket issues i know of, either. so, its likely that any failed parts from overheating or anything related were replaced before i got the car.

i talked to an independent tech that works on Hondas and he said that the rust and crap running thru the system could have pulverized the valve over time. so, add this into the mix of overheating and maybe it all adss up.

since this post i discovered some small, white, oval, shaped plastic pieces lying under the car after backflushing. i'm fairly certain that the plastic is the valve broken up and melted into these shapes. just wish i knew what caused this phenomena.