heater core - Toyota Nation Forum : Toyota Car and Truck Forums

***Edmond*** · 11-30-2004, 04:42 PM

Hey guys,

My heater is blowing out cold air and someone told me something about some valve being stuck on the heater core or something like that.

What does it look like?
Where is it located?

***Edmond*** · 12-01-2004, 12:36 PM

anyone? It's starting to snow and not having heat to defrost really sucks!

KILLACAMNY · 12-01-2004, 03:07 PM

The heater core might not be the problem. Try installing a new thermostat. Thats the valve that may be stuck open. It should be located inside the inlet where the lower radiator hose connects to. That was my problem last winter (cold air thru the heater) and it took like 30 min to swap out, then again I have a 4 cyl. Not an expensive piece either.

Good luck.

crah · 12-01-2004, 07:33 PM

Well it could be a couple of different problems. If it is a bad thermostat (hopefully) your temp gauge will run cool. If it is working properly your gauge should sit at right about half after warming up. The other problem would be related to the heater core. That could be a lot of money depending on exactly what's wrong with it. We need some more details. Do you have a haynes manual? That will tell you where it is located for your specific year.

***Edmond*** · 12-01-2004, 09:34 PM

Hey guys,

The temperature gauge inside the car stays at half when it warms up. The car doesn't overheat.

I don't have a Haynes manual, however, I do have a Chilton manual.

es250nut · 12-01-2004, 10:28 PM

Two things it is most likely to be:

1: Heater core bypass door... Controlled either directly by cable from the climate control or in an electronic system by an actuator. Located in the HVAC unit under the dash.

2: Heater core flow valve... Again controlled either directly by cable from the climate control or in an electronic system by an actuator. Located next to the firewall trace down the hoses that lead from the engine to your firewall, one will have the valve on it with a cable coming out from the firewall that opens and closes it.

It isn't very likely the heater core itself is bad unless it is plugged up with crap. The other way your heater core would be bad is if it were leaking, in that scenario you would probably still have heat, but you would also have fogging windows and most likely would be able to smell antifreeze. I've covered troubleshooting in other posts, do a search on "climate control".

burchard · 12-02-2004, 09:53 AM

In my 95 4cyl had the same problem. I found out that it was the valve mentioned by es250nut in point 2 of his post. The valve handle that connects to the wire comming out of the firewall was loose. I put the heater switch in the cold position and thight the screw up. If the screw keeps turning because the screw thread in the valve is gone south, put some plastic weld in the screw or install a bigger screw. Good luck

***Edmond*** · 12-04-2004, 12:33 PM

Quote:

Originally Posted by burchard

In my 95 4cyl had the same problem. I found out that it was the valve mentioned by es250nut in point 2 of his post. The valve handle that connects to the wire comming out of the firewall was loose. I put the heater switch in the cold position and thight the screw up. If the screw keeps turning because the screw thread in the valve is gone south, put some plastic weld in the screw or install a bigger screw. Good luck

I just did what you and es250nut recommended to do and I have heat!

You guys are so freakin' awesome. The little plastic wings were broken off. I just put it on the heat position and tightened the screw. I'll end up replacing it in the spring but having heat in the winter is a good thing here in Chicago.