How do you determine if the cause of your 1991 Honda CRX overheating is the water pump or thermostat?

Answer 1

first, with engine cold and off. second,take radiator cap off and disconnect top radiator hose from the radiator side and guide the top hose disconnected end toward ground. third, turn engine on and the heater. four, rev the engine to about 1500-2000 rpm. as the engine temperature gauge neeedle move up about minimum 1/4"(warm temperature) you should be able to see warm to hot water shoot out of the disconnected end of the hose 15 to 30 seconds at a time. that is the tell sign of thermostat opening(water shooting out) closing(water stop). if water does not shoot out with temperature gauge reading past half mark, check to see water moving inside the radiator filler hole. if no movement, water pump is defective. hope it helps. could also be the head gasket. I've had 7 CRX's and 3 of them had h/g failures. check for water/oil mixing, or coolant loss from a constantly overfull overflow bottle. ANSWER themstat cost 15bucks, replace it, its a good idea anyway, and its very easy to replace usually water pump go back, it make noise around that area, and also leak fluid around there. if u over heat at dead stop but cool of while it drive. then u have fan not coming on problem. if it just won't stop over heat no matter what speed u at, usually are themostat. if u rev up u see temp go down or high, water pump,