Rav 4 Heating

[monkeyman1973]

Hi my wife's Rav4 is blowing cold air constantly. 1998 2.0l freesport 16v. The engine isn't overheating. I've checked the coolant level in the radiator, as constant cool air can be an indication of no water in radiator, from my experience. I think it may be thermostat. I've bought a replacment but haven't fitted it yet. It's 17 years since I last did anything like that. I've also turned the engine on and left idle for 15 mins to check hoses. top one was hot, but bottom one was cold. What is that indicative of? Also if it is thermostat a few pointers on how to replace would be magnificent. She is hinting at a new car if I dont sort her heating out!! Not an option. Thanks. Monkeyman1973

[Parts-King]

top one was hot, but bottom one was cold. What is that indicative of?

A properly working engine!

Seriously though, the top hose will be hot, the hot water from the engine is returned to the radiator, the coolant then goes down the rad, cooling as it drops to the bottom, and comes out of the bottom hose much cooler. Where does the temp gauge sit? 1/4 or 1/2 hot??? It should go above half to start, and then fall back slightly to about halfway on the gauge, if it's cooler than this, then the thermostat is sticking "Open" causing the water to circulate quite cold. There is also a possibility that the valve on the bulkhead is not allowing water through to the heater, because it is stuck closed, either way, you need to isolate each item in turn. The most likely problem is the thermostat sticking open, quite common on older cars

Kingo