Replaced heater core, but no heat? (air pocket maybe?)

[~SlideWays~]

I had my heater core recored its all back in now but the problem is that I get no heat - just cold air.

Is it possible there is an air pocket? If so, how do I fix it?

Also there is an actuator which opens and closes the flaps which cover the heater core, should this open as soon as the switch is moved to "hot" or is it controlled another way?

Any help would be appreciated. (I need to take this car on a holiday in less than 2 weeks!)

[catchafox]

the heater "tap" should open as soon as the temp controller is moved off cold, run the engine up till fully warm and feal the temp of the pipes into your heater core from the fire wall. both pipes should be hot to the touch if not theres a problem, I suspect the tap has jamed shut and needs replacing. Revving the engine at 2-3000 rpm with the heater on full should remove any air pockets in the core, check your coolant levels when cold so you dont burn your self with hot water.

[Santa'sBoostinSleigh]

same kinda thing happened to me after my transplant in my racecar
heater didnt seem 'hot' any more
i think it was due to air pockets in the coolant lines
forgot about reckecking to see what its like now
will do at some stage (if i remember)

[~SlideWays~]

the heater "tap" should open as soon as the temp controller is moved off cold, run the engine up till fully warm and feal the temp of the pipes into your heater core from the fire wall. both pipes should be hot to the touch if not theres a problem, I suspect the tap has jamed shut and needs replacing. Revving the engine at 2-3000 rpm with the heater on full should remove any air pockets in the core, check your coolant levels when cold so you dont burn your self with hot water.

Well I took the tap off and CRC'd it and was easy enough to push in and out but then when it was back in it made no difference

The pipes to the heater definitely aren't getting hot or even warm.

Will it definitely be the "tap" even though I can open and close it with my finger? ie should it be easier to move.

By the way it isn't a manual heater switch, its electonic.

Damn not long till I go on holiday, bloody thing

[matt dunn]

Well I took the tap off and CRC'd it and was easy enough to push in and out but then when it was back in it made no difference

The pipes to the heater definitely aren't getting hot or even warm.

Will it definitely be the "tap" even though I can open and close it with my finger? ie should it be easier to move.

By the way it isn't a manual heater switch, its electonic.

Damn not long till I go on holiday, bloody thing

Does the tap have a cable going to it. It must do,
which means the hot cold slide will have a cable from there to the tap.
Does the tap move when you move the slide?

The fully elec ones that have no cables also have no tap, just flaps to direct the air.

OR

Pull the tap out, make sure it is open and you can blow through it,

refit it in the open position and leave the cable off it,
bleed it and see if it gets hot.

If not,

undo one only of the heater hoes from the core. Stick the hose into the hose not the core and turn it on.
A little flow, not too much pressure and run it till you get a good constant flow out of the core where you pulled the hose from.
Then reconnect and retry.

Then..............
??

[sergei]

on my AE101 and ST165, both are fully electronic, and they have both taps (in engine bay), the tap is actuated by a servo, if the interior temp sensor is not connected the servo will behave randomly... Servo is inside of the car, just above ECU, it is connect to tap through cable.

[~SlideWays~]

Its definitely not a cable type tap, its an actuator type setup with a vacuum hose on the top and 2 wires/plugs which look like they are just temp sensors.

I can manually push the tap open with my finger but nothing seems to happen at all when the switch is moved to hot.

The flaps are look they are also controlled by an actuator but this seems to always be closed, I've tried holding them open manually but still dont get any heat....this could be a different problem altogether because the pipes aren't getting hot either so it must be the tap or however the tap is controlled.

There are so many wires and hoses that its hard to tell which is for the heater.

This is on my '83 ae86 btw. Strangely enough my '87 GTZ has the manual cable tap even though it isn't as old?!

[Loudtoy]

I would suggest taking one of the hoses off the heater, try and get the one straight after the solenoid type thing you a re talking about, Somehow or another connect your common garden hose into it and using your common garden hose pressure make sure you have flow through the heater core. Why did you get the core reconditioned?? It'squite possible the the lines are rather full of gunk, had this happen on my truck the other day and you wouldn't believe how much shit there was in there. Mind you with around 20 litres in the cooling system of it i guess there's a bit more room for it to sit than your average car. After all the cleaning of it tho the heater worked good as anything maybe even a bit to good

[~SlideWays~]

I would suggest taking one of the hoses off the heater, try and get the one straight after the solenoid type thing you a re talking about, Somehow or another connect your common garden hose into it and using your common garden hose pressure make sure you have flow through the heater core. Why did you get the core reconditioned?? It'squite possible the the lines are rather full of gunk, had this happen on my truck the other day and you wouldn't believe how much sh*t there was in there. Mind you with around 20 litres in the cooling system of it i guess there's a bit more room for it to sit than your average car. After all the cleaning of it tho the heater worked good as anything maybe even a bit to good

It had the core replaced because it was warped and leaking, I might just bypass the tap for now since I need to make sure I can demist the windscreen while I'm on holiday in a weeks time.

Its driving me nuts though, cant figure out the problem.

When I took the tap off, both pipes had water in them but one was brown and the other green (anti freeze). I will check to see if the "brown" one is maybe blocked, good thinking batman!

Either that or its a problem with the control of the tap...no idea how I'm going to figure that out though.

[jondee86]

On NZ spec '84 AE86 the heater tap is cable controlled from the slide.
One hose in connected to the RWD water pipe that runs from the back
of the water pump. The other hose connects to the outlet from the
thermostat sensor block on the back of the head. The tap is mounted
up high on the firewall where it is easy to see.

If you can manually operate your valve, try it in both the "open" and
"closed" positions with the engine running and at normal operating temp.
If this doesn't give you heat, then you have a blockage.

Hot water flows from the thermostat sensor block to the tap, then to the
heater core. I am assuming the the type of tap is the only difference in
the plumbing... maybe you have climate-air ?? Flaps will be to control
where the air goes... recirc, screen, vents etc., and should not have any
affect on the temp of the heater core.

If you have green water in the hose after the tap, but not green water
in the hose coming from the heater core back to the water pump, then
the core is blocked But check that you haven't twisted/crimped/kinked
a hose under the dash when putting the heater back in place. Hope this
helps

Cheers... jondee86

[~SlideWays~]

On NZ spec '84 AE86 the heater tap is cable controlled from the slide.
One hose in connected to the RWD water pipe that runs from the back
of the water pump. The other hose connects to the outlet from the
thermostat sensor block on the back of the head. The tap is mounted
up high on the firewall where it is easy to see.

If you can manually operate your valve, try it in both the "open" and
"closed" positions with the engine running and at normal operating temp.
If this doesn't give you heat, then you have a blockage.

Hot water flows from the thermostat sensor block to the tap, then to the
heater core. I am assuming the the type of tap is the only difference in
the plumbing... maybe you have climate-air ?? Flaps will be to control
where the air goes... recirc, screen, vents etc., and should not have any
affect on the temp of the heater core.

If you have green water in the hose after the tap, but not green water
in the hose coming from the heater core back to the water pump, then
the core is blocked But check that you haven't twisted/crimped/kinked
a hose under the dash when putting the heater back in place. Hope this
helps

Cheers... jondee86

There is no hose under the dash, the core metal pipes stick through the fire wall, is this different to the NZ new ones? It is definitetly not cable controlled as I can see the electonic points at the back off the temp switch.

Also the tap can only be held open by pushing your finger down the hole (while it is off the car), there is no lever like on the cable controlled taps I've seen.

Bugger, still a mystery. Only possibility I haven't tried is that a pipe is blocked or if there is an electical problem.

[85AW20v]

You could bypass the tap and just have it going all the time till after your holiday.

[jondee86]

Yeah... good call, just like you say, the pipes poke thru the firewall, and
no hoses under the dash. So to check the core for any blockage, you
just have to do as previously suggested... disconnect some hoses and
try squirting a bit of water thru with a garden hose. Make sure you
disconnect between the valve and the core so as even if the valve is
kaput, it is not in the way of water flow.

If your valve has a solenoid or a mushroom shaped diaphragm on top,
it will be some type of servo operated valve. Sometimes they need to
have flow thru them in the correct direction... usually marked with an
arrow. If you put it in backwards, it can act like a one way valve. Worth
checking

If it has a diaphragm on top, you should be able to get the valve to
move by sucking or blowing on one of the small hoses attached. Again,
if the hoses have been off, could be worth checking that you haven't
swapped them around.

Cheers... jondee86