[jonwhite]

I have a 2002 Corolla with a 1zzfe engine which had the disappearing oil problem. I pulled the pistons, drilled 4 more holes in each piston, changed the rings, and rod c/s bearings. No more disappearing oil....I think! But now the heater only blows cold air. The fan is working OK at all selections.

I tried venting air out of radiator system by removing the radiator cap, running the engine for five minutes until it was warm but that was no help. The upper hose to the heater core gets hot but lower one doesn't so it seems that something is preventing the hot antifreeze from circulating through the heater core.

There is supposedly an EFI or F-Htr fuse in the fuse box just behind the car's battery. It's a black cube about a quarter inch square with two gold and two silver prongs. What does it control? Does it only control the fan or something else like a solenoid that would allow hot antifreeze to enter the heater core?

Any help would be greatly appreciated!

Jon White

 

[KarlH]

Sounds like you have a clogged heater core... No solenoid controlling hot coolant into the heater core on an 8th Gen Corolla..... Non heat issues when the engine is warm may be caused by something wrong in the climate control unit (switches) in your car, low on coolant or stuck open thermostat...

When you have such a change between temperature in heater core hoses, I would highly suspect that you have a clogged heater core...

You should flush the core if this is the problem...

Cheers

 

[jonwhite]

heater blows only cold air

Yo Karl !

Thanks for your reply! 98 people looked at my post but you were the only one who replied and the video you suggested by Mike the Mechanic was what I needed. Without your reply I probably would have flushed the heater core using the intake hose and clogged it even more! When I did flush it with water from a water hose out came some black specs but also some large circular chunks of foam, about the size of a dime with some trashbag like thin plastic stuck on the ends of the foam. I have no idea where that came from. Any way, I flushed it out, ran the engine to operating temp for about 5 minutes, but no change. But I found that both heater hoses were "cold" which meant no antifreeze was going through the heater core. So I drove it about a mile and all of a sudden it started blowing hot air. She be cured! As a pastor I truly appreciate you telling me how to "lay hands on my lady and cast out her demon!" I figure you saved me a minimum of $400!

Blessings....His and Merry Christmas !
Jon White

 

[KarlH]

Jon,

Glad to help... Thanks for posting your results. Many times, people come here for answers and you never find out the "the rest of the story".

Merry Christmas to you and yours as well!

-KarlH

 

[Truck7575]

I am having a similar issue... Had what I thought was oil in the antifreeze and the car was going through a crazy amount of oil so I used some stuff that was suppose to fix head gasket leaks... Well of course that plugged my heater core... I have flushed the hell outta it and it did start worki g but has since stopped working again... I went ahead and bought another heater core but I'm debating on weather to install it or not... Any good suggestions? Also know any good sources for heater core replacement videos or procedure?