Heater issues-no hot air

Had this problem for a while but never bothered my arse to fix it.

Heater speed works fine,a/c works fine,no air lock and the arm that switches between hot and cold works fine and is connected

That leaves me with the matrix and I also read on another forum that the solders on the heater control panel can bugger up,any1 had this issue or know how to check it?

It's not a stuck thermostat either,heating stays cold no matter how long I drive around

Cheers

M

No1 have any ideas?

I presume in the title you mean "no warm air" instead of "no cold air". That changes things a bit.

You say you don't have an airlock, but do you know that for sure? One of the only sure-fire symptoms of an airlock is having no warm air from the heater. The engine won't generally overheat if the matrix (and only the matrix) has an airlock in it, so you can't use that as evidence.

Is the engine water temp (dashboard gauge) reading normal?

You could feel the hoses going into and out of the matrix: 2 hoses very close to each other disappearing into the bulkhead on the passenger side. I guess the normal result is that one should be hot and the other should be warm/hot, but I would double-check that by searching on here.

Another possibility is that the matrix is blocked (silted up with limescale etc).

You could try flushing the matrix through with hose water: proceed with caution because if you turn the pressure up too much you might spring a leak in the matrix. I've also read on here that someone (Dude?) used drain cleaner to clear out a matrix.

have you checked the little joining rod to the conrols in the passenger foot well, sometimes they come off

As suggested - are you sure there is no air lock? I had one after changing the matrix and only really resolved it by parking on a steepish hill to bleed out the airlock - after that it worked fine!

When you press the buttons to switch the air circulation method do you hear the flap move - as that rod, as also suggested, does come loose.

Yeah I meant no hot air,my bad. I've already checked the rod and I can see it operating,I'll try parking it on a hill and see where I go from there.will keep use posted

Cheers

Best change your thread title as its now just a little missleading

Run the engine with the rad cap off till it gets to normal running temp, turn the

heater to max hot with the fan on and watch for bubbles coming out the rad, if its an

airlock after a while the bubbles should stop, top up with coolant and pop the cap back on.

You should have hot air now.

If it keeps bubbling and still no heat i've found raising the revs a bit helps so try that.

Keep checking the temp gauge whilst doing the above and check the heater to see if your getting nice hot air, it should be hot and not just luke warm

When your done fill the expansion tank to approx half way, as the system cools it will draw this coolant into the rad.

If that doesn't work it could because your matrix is gunged up, does the car run at normal temp otherwise.

You don't have a soggy passenger footwell and a strange smell of coolant when you turn the heater on do you?

Mine was very easy to diagnose.. as soon as I turned the heating on the car filled with a lovely sweet smelling black smoke as the leaking coolant burned off on the rad! Fun times.. followed by a few days ripping the dash out to replace it

I would change the thread title if I could,can't seem to find the option,it's fine everyone is replying now lol

Yeah car runs fine otherwise,heats up fine,has never overheat.there is no dampness in the footwell either.

Once the pissin rain gives me a break I'll try parking her on a hill and let use know how I get on.who knows when this rain will give in though

M

to change the tile go to your first post and then edit go to advanced and the go to the tile and change it

I would change the thread title if I could,can't seem to find the option,it's fine everyone is replying now lol

 

Yeah car runs fine otherwise,heats up fine,has never overheat.there is no dampness in the footwell either.

 

Once the pissin rain gives me a break I'll try parking her on a hill and let use know how I get on.who knows when this rain will give in though

 

M

You don't need a hill i've done a few mkivs now including my own 3 times and they bleed up fine

on level ground.

Have you checked your coolant level whilst you've had this problem ?

Is the rad full and the expansion tank half full approx, if its still the original for what they cost

i'd fit a new rad cap (o/e Toyota)

im having simular issues, my heater only ever goes luke warm never hot and the temp gauge has always been fine never overheated and ive noticed im losing coolant from the expansion bottle...

Parry, it sounds like you have 2 issues:

1) your heater matrix is just inefficient through old age. Maybe the core is clogged with sediment. You can try flushing it through in both directions with hose water. Have a search on here for how to do it. I've done that to mine and it can help a bit, although nowhere near as good as fitting a new matrix.

2) Coolant loss: This shouldn't be happening and is very likely a separate issue. What's the rate of loss? (litres/week? litres/hour?) Can you see any coolant-stained residue on the radiator or coolant hoses? It's possible your rad cap is tired and doesn't form a decent seal any more, thus allowing some coolant to boil off, but that's no more than a guess and it miht be something completely different.

Parry, it sounds like you have 2 issues:

1) your heater matrix is just inefficient through old age. Maybe the core is clogged with sediment. You can try flushing it through in both directions with hose water. Have a search on here for how to do it. I've done that to mine and it can help a bit, although nowhere near as good as fitting a new matrix.

2) Coolant loss: This shouldn't be happening and is very likely a separate issue. What's the rate of loss? (litres/week? litres/hour?) Can you see any coolant-stained residue on the radiator or coolant hoses? It's possible your rad cap is tired and doesn't form a decent seal any more, thus allowing some coolant to boil off, but that's no more than a guess and it miht be something completely different.

Thanks for the reply, with the coolant loss its not much I just have to top up the overflow bottle say every 2-3 weeks im guessing I probably have a leak somewhere although its not obvious as I have checked with the rad cap isnt there a test you can do to make sure its forming a good seal?

as for the heaters it was fine when the car was an na but as soon as I went na-tt ive never had hot air only luke warm so weather thats just a coinsidence or not im not sure

Ive read a few instances of people bypassing the matrix - Are the in / out pipe connections to the bulkhead pipes visible when you look under the bonnet Parry?

Although if it were bypassed I imagine all air coming from the vents would be the same as the external temperature..hmm

Thanks for the reply, with the coolant loss its not much I just have to top up the overflow bottle say every 2-3 weeks im guessing I probably have a leak somewhere although its not obvious as I have checked with the rad cap isnt there a test you can do to make sure its forming a good seal?

 

as for the heaters it was fine when the car was an na but as soon as I went na-tt ive never had hot air only luke warm so weather thats just a coinsidence or not im not sure

This may sound a bit mad but check the matrix hoses are on correctly, mine got fitted so the inlet was on the

outlet and outlet on the inlet, i got luke warm air out the heater and it took a bit of head scratching to realise

what was up.

Also if your rad caps the original for what they cost i'd replace it and i'd get the

system pressure tested, you dont need a specialist to do that and should be

cheap to do.

There's no traces of coolant around the engine bay so I doubt I'm loosing coolant that way,it usually leaves a stain when it drys up.il run her at the weekend with the cap off and double check the levels,will let use know how it goes

Cheers

Had a wee run up to temp on the driveway,both pipes going in and out the matrix are cold,car goes up to temp fine.

Will try again 2moro if the weathers alright on a slop,radiator is full and topped the other coolant up to the line

i had a similar problem, the controls had been disconnected on the back of the radio and i had forgotten to plug them back in. silly noz!

I'm sure I have all that plugged in,the amount of times I've had the dash in and out lol