1977 Celica heater issues...

['77 Celica 22R]

I have a '77 celica gt coupe. I noticed that the heater has not been working, and the temp gauge only ever reaches the first line at the bottom. I replaced the thermostat in hopes it was jsut old. Now the temp gauge gets a little above that lowest line, but it still blows cool air. I try to turn the air on recurculating to warm it, but it just fogs the wondows. Is it a bad heater coil? Some have suggested placeing cardboard just behind the grill to cut off some of the air intake to warm the engine up...but I rather not drive around with cardboard behind my grill. Any ideas?

Matthew

[stepho]

Your '77 is showing 2 very common (and separate) problems.

1. Temperature gauge.
Very common.
My '77 does the same.
There's nothing wrong with the engine.
Either the sender or the gauge is at fault.
Since you already replaced the sender, then it must be the gauge.
I chose to simply live with it.
If it ever climbs to the half way mark then it is ready to blow immediately (which happened to me a few years ago).

2. Heater blows cold air.
The heater termperature lever selects bewteen resistors - actually between off, a large resistor, a small resistor, a large resistor and no resistor (full power).
Quite often the connection between the battery and the resistors gets worn out by the lever rubbing on it for 30 years.

- Stepho

[xak5]

dude if your window fogs up from moisture your heater core is, infact, broken. check your coolant levels often untill its replaced. a temporary fix to this is to disconect the 2 hoses from the firewall and connect them togeather, by-passing the heater core. no heat, but no leaks. oh and if you want to test your gauge, turn the key on(not start) and ground out the wire on your temp sensor. if the needle on the gauge goes all the way to the top your gauge is properly functioning. grab a buddy and go test it, but most likely your gauge is fine.

[xak5]

oh and stepho, your thinking of the blower fan motor resistior, like the fan only works in one speed problem. no heat means broken heatercore

[stepho]

Yep, xak5 is right.
I mixed up temperature with fan speed.

Possible that the heater tap isn't opening.
There is a cable going from the temperature selector in the dash to the water tap in the engine bay.
This tap allows engine coolant to flow through the heater core.
Make sure that moving the temperature lever causes the tap to open and close (you will need a 2 people for this).
This also happened to me.
I replaced a stuck tap with one from a 1978-81 model.

Beware that a broken heater core means that engine coolant will find its way out of the engine (bad) and onto your carpet (bad) and the engine will soon overheat (very bad).
This happened to my wife's Cressida.
Good news is that it lets you know by blowing steam all over your window.
It was bad news but at least it alerted us to the problem before we overheated the engine.
If your car is still running then the heater core isn't broken.
Note that the tap only turns off one side of the heater so that water will not flow in and out.
If the core is broken (ie a hole) then water can still use the other end of the pipe to drain water out of the engine and onto the carpet.
This happened on my wife's Cressida before I thought it through (ie I closed the tap and filled the radiator but the problem happened again).

Another (more likely) possibility is that the heater core is full of gunk (that brown sludge often seen in radiators).

- Stepho

['77 Celica 22R]

hey stepho and xak5-

thanks for the suggestions. I have not noticed any coolant leakage anywhere inside or outside the car, so I don't believe there is a hole in the heater core. the coolant level is right on also, so i'm thinking that the heater core itself is just not working...do to age or gunk in it. I will also check the heater tap to see how that is working. thanks for the help though....it's really appreciated, especially with my gen 2!




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