Heater Stuck On

[CamMoore]

Hi Guys,

I have a 1991 2.1L van and I cannot turn the heater off. It's not the fan, it just blows hot air when I'm moving. When I adjust the controls I can only move the air from my face to my feet.

I traced one of the levers and it came to a junction in a hose and seemed to open and close the hose (see photo), but when I removed the clamp to have a look at it, what looked like radiator fluid started coming out.

Can someone please tell me what that junction does and why is it connected to the ac controls? Also can someone help me with turning the heater off or I will melt this summer!

Cheers!

[CovKid]

As you have summised, its a valve. They can be replaced but avoid Chinese copies. Mines the same to be honest - I just open a window if it gets too hot. I didn't feel it was worth doing unless I was doing a complete system flush.

[ghost123uk]

when I removed the clamp to have a look at it, what looked like radiator fluid started coming out.

It is radiator fluid ("coolant" as it is generally known), this where your heater gets it's heat from (or not, if it's in the "off" position )

Mine is stuck "on" too, though mine is a cable issue, not a faulty valve issue.

"We" don't need to worry about turning the heater off for at least 6 months from now so I will look at replacing my heater control valve cable (possibly dash out job) next spring.

Oh and welcome to club 80-90 CamMoore

[Bubble Meister]

The cable should have, on the valve, a silver clip to prevent the outer cable sheath from moving. If thats not fitted then the control cable is free to move about and not operate the valve correctly. The clip is available from brickwerks.

[CamMoore]

Thanks for the replies guys, and welcoming me to the club . I've had a T3 for three years now, thought it's about time to get on board!

I live in Australia, so sometimes will be traveling in temperatures upwards of 40 degrees celcius. So not having the hot air blowing would be a great benefit!

Is there a way to completely stop air coming into the cab? If I disconnect the hose next to it will that work? Also I've read that if you get air into the cooling system it can cause problems, will that happen to mine because I pulled that hose off for a few seconds?

Thanks

[ghost123uk]

Ah, Australia eh. If you send me an airline ticket I will come over and sort it out for you

If your valve is not shutting off you could replace it. It's quite an easy job. iirc the valve is the same as the ones fitted to Golfs and Sciroccos of the same era (but don't shoot me if I am wrong). Or you could just use a pipe clamp to crush the pipe near the valve (or further back, in the engine bay or under the van, but make sure it's the same pipe !!!). That would stop the flow of hot coolant to the heater and won't do any harm (but if you leave it like that for too long it might damage the rubber hose).



Re bleeding it. It depends how much coolant you lost. I would say that if it was less than a pint, you won't need to. To some extent these vans have a self bleeding system (that is what that very thin pipe is for that runs around the top edges of the engine bay hatch). However, these WBX engines don't like air in the cooling system, it can cause serious damage to them. For this reason it is a very good idea to keep an eye on your coolant levels (and to make sure your low coolant sensor is working) As you likely know, the white tank at the left hand side of the engine bay should be full to the brim, and the tank behind the number plate flap should be about 1/2 full. These checked with a cold engine by the way.

Details on best way to bleed the system are in our "wiki" a link to which is near the top left of every page on here.

[MidLifeCrisis]

Is there a way to completely stop air coming into the cab? If I disconnect the hose next to it will that work? Also I've read that if you get air into the cooling system it can cause problems

Nope - that other hose is the coolant returning from your heater to the engine so don't disconnect that!!
When you move the heater lever in the van you should be able to see a corresponding movement of the little metal arm on the valve you found under the van - does that all look like it's working correctly?

Those valves do seem to wear out and just let coolant through all the time (as you are experiencing);
They can be replaced but it's a bit fiddly!!
Here's a video of someone doing it but they make it look deceptively easy!!
https://m.youtube.com/watch?v=35MkLMMQrhc

[ghost123uk]

Those valves do seem to wear out and just let coolant through all the time (as you are experiencing);
They can be replaced but it's a bit fiddly!!
Here's a video of someone doing it but they make it look deceptively easy!!
https://m.youtube.com/watch?v=35MkLMMQrhc

Certainly easier when up in the air on a ramp like that ^^^

[CamMoore]

Nope - that other hose is the coolant returning from your heater to the engine so don't disconnect that!!
When you move the heater lever in the van you should be able to see a corresponding movement of the little metal arm on the valve you found under the van - does that all look like it's working correctly?

Yes, when I move the middle lever the metal arm moves on the valve. So just to clarify, the hose with the valve is coming from the engine, and the other is going back to the engine? So to test whether the valve is working, you would see if any coolant is coming out of the top of the valve when then valve is meant to be closed? (obviously using clamps so I don't lose a heap of coolant)

Is there a way to stop airflow into the cabin completely? Is one of the levers meant to stop that?

Re bleeding it. It depends how much coolant you lost. I would say that if it was less than a pint, you won't need to. To some extent these vans have a self bleeding system (that is what that very thin pipe is for that runs around the top edges of the engine bay hatch). However, these WBX engines don't like air in the cooling system, it can cause serious damage to them. For this reason it is a very good idea to keep an eye on your coolant levels (and to make sure your low coolant sensor is working) As you likely know, the white tank at the left hand side of the engine bay should be full to the brim, and the tank behind the number plate flap should be about 1/2 full. These checked with a cold engine by the way.

Thank you! It should be fine, I got the hose hooked up pretty quick after getting a face full! I will test the censors though.

[ghost123uk]

I will test the censors though.

As you likely know, the sensor is built into the top of the left hand white tank in the engine bay. Unplugging the lead off the top should trigger the low coolant warning light (in the temperature gauge) and on some variants, also will shove the temp needle over to the right (so you can see the red LED clearly). It can take a few seconds before the warning is triggered. Also, it will not re-set after you put the lead back on until you turn the ignition off and on again (it's a fail safe thing).

[CamMoore]

As you likely know, the sensor is built into the top of the left hand white tank in the engine bay. Unplugging the lead off the top should trigger the low coolant warning light (in the temperature gauge) and on some variants, also will shove the temp needle over to the right (so you can see the red LED clearly). It can take a few seconds before the warning is triggered. Also, it will not re-set after you put the lead back on until you turn the ignition off and on again (it's a fail safe thing).

Cheers, I will test it tomorrow. I asked my mechanic last time I took it in about my temp gauge needle never rising. He said that the temp sensor works but the gauge needs to be re-calibrated. Is this something you can do yourself or do you need special tools?

[ghost123uk]

So just to clarify, the hose with the valve is coming from the engine, and the other is going back to the engine?

Yes, but note these two pipes are only for the heater only, so clamping them won't affect the engine cooling, it will just make the heater blow cold.

So to test whether the valve is working, you would see if any coolant is coming out of the top of the valve when then valve is meant to be closed? (obviously using clamps so I don't lose a heap of coolant)

Not much point in doing all that. You already know your valve is not closing when it appears it should be closed

Is there a way to stop airflow into the cabin completely? Is one of the levers meant to stop that?

There are some variations in heater controls from different types of T3. On mine I can adjust the air flow to the dash de-mist vents from full to none with one lever, and adjust the air flow from the lower outlets (by your feet) from full to off with another lever. the flow rate is indicated by a ling thin white triangle on the heater control panel. Yours might be different. Anyway, best plan is to stop the flow of hot coolant to the heater (in your hot climate ) by either changing the valve or just clamping one of the heater pipes somewhere along their route.

Look, just send me a ticket and I will personally come and fix it

[CamMoore]

Anyway, best plan is to stop the flow of hot coolant to the heater (in your hot climate ) by either changing the valve or just clamping one of the heater pipes somewhere along their route.

Okay, I'll give that a go. It should make for a much more enjoyable ride!!

Look, just send me a ticket and I will personally come and fix it

I would have to fly you over for a month for all the things I want fixed!!

Thanks heaps for your help. My first post and I already love this forum, I can't believe I have only just found it!

[ghost123uk]

I asked my mechanic last time I took it in about my temp gauge needle never rising. He said that the temp sensor works but the gauge needs to be re-calibrated. Is this something you can do yourself or do you need special tools?

Jeez, well don't take it back to him for ANYTHING. That answer he gave was total bull poo. Calibrating my a***.

Temp gauge not rising = (in order of likelihood)

1) - Sensor duff (pretty common) - it's the one facing towards the front on the stat housing. Try pulling the connector off and shorting the 2 connector sockets on the plug on the wire with a paper clip or similar. This should send the gauge quickly over to max. If it does, then it is a faulty sensor (if ordering a new one, be careful to order the right one !!)

2) - Wiring issue any where from the sensor to the actual gauge. There is a white connector hanging up inside the dash, near where your knee is. They are well known for being dodgy. The ribbon cable that plugs into it is quite delicate (be careful with it) and where it connects into the white plastic plug often causes various dash related issues.

3) - Wiring issues on the (delicate) blue plastic PCB membrane that is at the back of the dash components, connecting them all up electrically. If you are a stranger to 12 Volt electrics you will need assistance from someone who does know (as in really does know, not just says they do) to sort that out.

4) - The 10 Volt regulator is blown (does the fuel gauge work properly? - if "yes" then this is not the problem.

5) - The gauge itself is knackered = pretty rare for that to fail though.

6) - Some twit has removed the thermostat.

Lots more reading in our "wiki" on all this. Here is just one article (there are more on all this) = https://club8090.co.uk/wiki/VW ... uel_gauges" onclick="window.open(this.href);return false; and this = https://club8090.co.uk/wiki/Co ... ht_on_dash" onclick="window.open(this.href);return false;

[CamMoore]

[quote]Jeez, well don't take it back to him for ANYTHING. That answer he gave was total bull poo. Calibrating my a***.[/quote

Wow that surprises me, he's normally pretty good. He's a vw trained mechanic and owns two T3's himself, however I know he's not very good with electrics. I'm trying out another mechanic next month, I'll see how he goes.

I'll have a play around tomorrow, I'd say it would be one of the top three. I've got a pretty good knowledge of 12v systems, so no worries there (I study mechatronics engineering so I should have!). It's the mechanical side of things I struggle with.

My fuel gauge works properly, though it seems to run empty before the gauge reads 0, but I assume that's just a T3 thing.

I'll be sure to read up a lot more before I ask any more questions.

Thanks again for your help!