skshepherd

Hey guys,

The heat just went out in my 97 4runner. I have plenty of coolant, water pump appears to be working, rear heater works, but front does not. Sometimes when I first slide the temp switch over to heat it will be kinda warm for about a minute then goes back to blowing cold air.


I have not found any coolant leaks inside the 4runner and do not smell any.

Could it be that the heater core is clogged and a system flush might cure the problem?

Thanks,
Steve

breknraj

Perhaps a clog, but I would check the actuator cable on the heater valve on the firewall. Make sure that it is actually moving the valve.

MTL_4runner

Steve, it sounds like you either have a clogged heater core or more likely you've got a problem with the climate controls. On your 97 you just have the manual control sliders like I do and really there are two things that can happen. The coolant heater control valve can be stuck or clogged (check that it is open fully and the coolant can pass freely) or you have a malfunctioning air mix cable or air mix door (check to make sure the vent control doors and cables are adjusted and working properly and that it isn't mixing cold and hot air together......thus giving you cool air, which really sucks in subzero temps).

Also how is the temp on your coolant guage?
I assume fine since you tell me you're getting good heat in the rear.

skshepherd

Thanks for the reply guys! The temp gauge is at normal, and the valve seems to work as I can slide the slider and not that the valve is in a different position each time. I can hear the mix door opening and closing shut and there is a difference in air temp. when off heat it is really cold and on heat just plain semi warm to cold.

Is there an easy way to try and flush out the heater core? Could I do it and not have to flush the whole system. Would I have to worry about getting air into the system? Im guessing the whole system could use it. I asked the repair shop in town to do so when they did the timing belt but they did not.

I dont really have any good way to capture the old coolant and If I did no place to dispose of it. I dont really want it running down the driveway. Any tips or suggestions?

Hopefullly I can unclog it and not have to buy a new one.

Thanks again for the help.
Steve