Heater Problems. Any Experts?

[tjm]

I welcome some help from anyone who has investigated the heating/aircon on these cars. Car is a '99 2.3 GLX with manual aircon.

 

My main problem is that the aircon is not working but before I decide whether it is worth fixing it I want to be sure the rest of the system is ok. To that end I have a few issues......

 

1) The recirculation flap does not work - it is permanently feeding external air regardless of whether the switch is on or not.

I've removed the heater controls and there is vacuum getting to the switch. If I suck on the pipe to the heater the recirc flap can be heard to operate so I assume the switch is faulty. Anything else I should check before replacing it?

 

2) Even when the external air is cold (and the heat setting is on cold) the air from the vent is slightly warm. Enough to need the windows open to cool the car down. The heat control appears to work correctly and removing it and operating the wire to the heater by hand has the same affect (i.e. when pushed fully closed I still get some warm air).

If I had the aircon working this probably isn't a problem but as it is it isn't great!

Is this normal? Or do I have another fault?

I assume the heat level is controlled by some flap in the heater allowing heat from the heater matrix in. Is it possible to check this without removing the dashboard?

 

3) I noticed some sort of switch or solenoid with what looks like vacuum hoses attached. One of the hoses was not attached but I cannot work out what it does. I've re-attached the hose and everything appears to operate as it did before.

This valve is on the bulkhead behind the coolant tank.

In the picture below two pipes are marked "vacuum hose". the black shiny one was the one not connected but it goes into the right hand (looking at it) side of the unit. the grey braided one goes to a T piece and the pipes from that go through the bulkhead to the heater area.

What is strange is that the grey pipe is soft and isn't what I would expect from a vacuum pipe.

Any ideas what it does?

 

Any help or explanations on how this heating system works will be gratefully received!

 

Br

Toby

http://www.tw.ghatzo.co.uk/uploads/cars/vacuum%20switch.jpg

[chrispb123456]

I welcome some help from anyone who has investigated the heating/aircon on these cars. Car is a '99 2.3 GLX with manual aircon.

 

My main problem is that the aircon is not working but before I decide whether it is worth fixing it I want to be sure the rest of the system is ok. To that end I have a few issues......

 

1) The recirculation flap does not work - it is permanently feeding external air regardless of whether the switch is on or not.

I've removed the heater controls and there is vacuum getting to the switch. If I suck on the pipe to the heater the recirc flap can be heard to operate so I assume the switch is faulty. Anything else I should check before replacing it?

 

2) Even when the external air is cold (and the heat setting is on cold) the air from the vent is slightly warm. Enough to need the windows open to cool the car down. The heat control appears to work correctly and removing it and operating the wire to the heater by hand has the same affect (i.e. when pushed fully closed I still get some warm air).

If I had the aircon working this probably isn't a problem but as it is it isn't great!

Is this normal? Or do I have another fault?

I assume the heat level is controlled by some flap in the heater allowing heat from the heater matrix in. Is it possible to check this without removing the dashboard?

 

3) I noticed some sort of switch or solenoid with what looks like vacuum hoses attached. One of the hoses was not attached but I cannot work out what it does. I've re-attached the hose and everything appears to operate as it did before.

This valve is on the bulkhead behind the coolant tank.

In the picture below two pipes are marked "vacuum hose". the black shiny one was the one not connected but it goes into the right hand (looking at it) side of the unit. the grey braided one goes to a T piece and the pipes from that go through the bulkhead to the heater area.

What is strange is that the grey pipe is soft and isn't what I would expect from a vacuum pipe.

Any ideas what it does?

 

Any help or explanations on how this heating system works will be gratefully received!

 

Br

Toby

http://www.tw.ghatzo.co.uk/uploads/cars/vacuum%20switch.jpg

Hi Toby

Your flap problem may be due to debris ie leaves and dirt entering intake through ill fitting pollen filter at some point in it's life, if you say the operating levers are moving to there full extent, the door/flap seals may be damaged.

The valve your refering to looks like the ECOV (electronic change over valve) it's to aid quicker warm up of the front heater in cold weather.

[tjm]

Hi Toby

Your flap problem may be due to debris ie leaves and dirt entering intake through ill fitting pollen filter at some point in it's life, if you say the operating levers are moving to there full extent, the door/flap seals may be damaged.

The valve your refering to looks like the ECOV (electronic change over valve) it's to aid quicker warm up of the front heater in cold weather.

 

Thanks Chris,that is very helpful.

 

I've been investigating a bit further (removed glove boxes etc and heater fan) and the flap for the recirculation is working fine - it appears it is just the vacuum switch. I took the switch apart and there is a rubber seal that appears to have gone all soft and gooey. So a new switch is needed.

 

I also removed the control to the heat flap. Operating it by hand and it gives a satisfying clunk and an obvious change in the noise of the airflow so I think it is working 99% at least. I can get the same closing clunk if I operate the control quickly so I think it is closing properly.

I did wonder about leaves but there wasn't any in the fan or evaporator housing so I think it is probably ok.

 

It is interesting that when the engine has just warmed up I get completely cold air but when the car is then left sitting in the sun for 30 minutes the air is a bit warm. I am starting to suspect the heater is working fine (apart from the recirc) but that the whole heater is being warmed up when left (probably partly by the heater matrix and partly by the sun on the dash). Not much I can do about that and I don't think I would notice it if the aircon worked as that would then cool everything down properly.

 

I also discovered the strange valve (ECOV?) is T'ed off the vacuum feed to the front heater (grey hose) and controls the vacuum feed to the rear heater (black hose). I guess from your comments that switching the vacuum shuts down the rear heater in some way.

 

Anyway, it looks like a new switch and I can get the recirculation working. Then it is just a case of working out if it is worth spending 1/3 the cost of the car getting the aircon working :D

[chrispb123456]

Hi Toby

Your flap problem may be due to debris ie leaves and dirt entering intake through ill fitting pollen filter at some point in it's life, if you say the operating levers are moving to there full extent, the door/flap seals may be damaged.

The valve your refering to looks like the ECOV (electronic change over valve) it's to aid quicker warm up of the front heater in cold weather.

 

Thanks Chris,that is very helpful.

 

I've been investigating a bit further (removed glove boxes etc and heater fan) and the flap for the recirculation is working fine - it appears it is just the vacuum switch. I took the switch apart and there is a rubber seal that appears to have gone all soft and gooey. So a new switch is needed.

 

I also removed the control to the heat flap. Operating it by hand and it gives a satisfying clunk and an obvious change in the noise of the airflow so I think it is working 99% at least. I can get the same closing clunk if I operate the control quickly so I think it is closing properly.

I did wonder about leaves but there wasn't any in the fan or evaporator housing so I think it is probably ok.

 

It is interesting that when the engine has just warmed up I get completely cold air but when the car is then left sitting in the sun for 30 minutes the air is a bit warm. I am starting to suspect the heater is working fine (apart from the recirc) but that the whole heater is being warmed up when left (probably partly by the heater matrix and partly by the sun on the dash). Not much I can do about that and I don't think I would notice it if the aircon worked as that would then cool everything down properly.

 

I also discovered the strange valve (ECOV?) is T'ed off the vacuum feed to the front heater (grey hose) and controls the vacuum feed to the rear heater (black hose). I guess from your comments that switching the vacuum shuts down the rear heater in some way.

 

Anyway, it looks like a new switch and I can get the recirculation working. Then it is just a case of working out if it is worth spending 1/3 the cost of the car getting the aircon working :D

Hi again

your right about the ECOV operates a water valve that shuts off the rear heater, also my car is black and when the suns been on it even with the air-con on it still takes a while to start cooling down.

If your near the Maidstone area I know of a good mobile air-con engineer.

[tjm]

Hi again

your right about the ECOV operates a water valve that shuts off the rear heater, also my car is black and when the suns been on it even with the air-con on it still takes a while to start cooling down.

If your near the Maidstone area I know of a good mobile air-con engineer.

 

Thanks, but I found a good aircon guy local to me (NE Hampshire). (www.coolzone-aircon.co.uk)

He only charged me