Air Con - Fogging And Damp Smell!

[peanutome]

I have a 2005 2.0 D4D Avensis and it seems to have the worst air con system of any car I have owned, but before I damn it too much I better find out if mine is broken or not.

Driving along and the windows will steam up intermittently with the air con turned on, the sudden misting is usually accompanied by a damp and musty smell. This will last for a couple of minutes and then start to clear and the smell goes, only to happen again a while later. With 4 people in the car in the wet weather at the moment it is impossible to stop the rear passenger windows from steaming up and the front one requires the demist button pressed all the time.

If I use the re-circ button the problem is worse! All previous cars I have had work with 4 people and 'dry' the air well enough to stop misting up, and it should work better with re-circ turned on as it is drying the same air over and over.

I had and Audi A8 and an Alfa 156 that both developed this sort problem and it turned out to be the drain being blocked that drains away the condensed water, (the bit that leaves a puddle on the floor when the car is turned off). I do not remember seeing this water draining from the bottom of my car recently and wondered if the Avensis has these drains and if they get blocked or not.

So my questions really are:

1 - Is this problem only me or is it common and indeed the Avensis Air Con is poo?

2 - How have people solved it?

3 - Is there a drain that may be blocked and if so where is it?

The air con has been serviced twice now, full re-gas and leak test, cabin filter changed etc etc.

I actually get less steaming up WITHOUT the so called Air Con being turned on!

Any help would be appreciated

Regards

David

[marama32]

Hi,

1, I would suggest having your aircon purged, cleaned & topped up at the likes of Kwik fit etc. for about £40.

2, The Above. Do you have good airflow coming from all vents in all positions? IF you don't check your pollen filter it could be blocked, chocked and or needing replaced.

My car does steam up if I use re circulation button, so I don't use it in Winter or cold periods, but not a problem in the summer etc.

3, I don't know of a drain on the Avensis system, but it may be there. Hopefully someone else can advise.

Cheers,

Marv

[igormus]

I have a 2005 2.0 D4D Avensis and it seems to have the worst air con system of any car I have owned, but before I damn it too much I better find out if mine is broken or not.

Driving along and the windows will steam up intermittently with the air con turned on, the sudden misting is usually accompanied by a damp and musty smell. This will last for a couple of minutes and then start to clear and the smell goes, only to happen again a while later. With 4 people in the car in the wet weather at the moment it is impossible to stop the rear passenger windows from steaming up and the front one requires the demist button pressed all the time.

If I use the re-circ button the problem is worse! All previous cars I have had work with 4 people and 'dry' the air well enough to stop misting up, and it should work better with re-circ turned on as it is drying the same air over and over.

I had and Audi A8 and an Alfa 156 that both developed this sort problem and it turned out to be the drain being blocked that drains away the condensed water, (the bit that leaves a puddle on the floor when the car is turned off). I do not remember seeing this water draining from the bottom of my car recently and wondered if the Avensis has these drains and if they get blocked or not.

So my questions really are:

1 - Is this problem only me or is it common and indeed the Avensis Air Con is poo?

2 - How have people solved it?

3 - Is there a drain that may be blocked and if so where is it?

The air con has been serviced twice now, full re-gas and leak test, cabin filter changed etc etc.

I actually get less steaming up WITHOUT the so called Air Con being turned on!

Any help would be appreciated

Regards

David

hi mate

there are three remedies:

- firstly -- have pollen filter changed;

- to be aired evaporator (arround 5 mins) before A/C turn OFF;

- to be checked system on gas leaks.

Good luck

Igor

[eddieinvader]

If you use recurculate the car usually fogs up anyway, I try to only use this for short periods if behind a smelly car or van.

[donnyvfr]

If you use recurculate the car usually fogs up anyway, I try to only use this for short periods if behind a smelly car or van.

changing pollen filter in my older avensis cured this

[igormus]

If you use recurculate the car usually fogs up anyway, I try to only use this for short periods if behind a smelly car or van.

my A/C has been permanently running either in Summer or in Winter + even on re-circulating mode -- the windshield has never been fogged, subject to polen filter is changed on time.

Cheers/Igor

[Thermal]

...

3 - Is there a drain that may be blocked and if so where is it?

Hi,

The Heater&Airconditioner repair guide, exploded drawings, show a "Cooler unit drain hose".

It is shown on the drawing where all interior components are, underneath the Air Conditioning Radiator Assembly.

Unfortunately, the drawing does not show where exactly this hose is connected, but since it is on the interior drawing I suspect it connects to the Air Conditioning Radiator Assembly under the dash somewhere, extending through the car's floor.

It may be worth checking, maybe this hose is blocked/cracked/loose or even missing in your car, so that the airco drains inside the interior, which would explain your steaming problem.

Hope this helps.

[Duffryn]

In theory, how often should the aircon be 'purged', or recharged, or overhauled in any way?

Mine seems to have problems demisting too.

[igormus]

In theory, how often should the aircon be 'purged', or recharged, or overhauled in any way?

Mine seems to have problems demisting too.

it is most individually depending whether or not you re satisfied with performance subject to a polen filter is in order.

no timing factor is stipulated in manual. all depends on ability to make an air chilled at small time period.

cheers/Igor

[Duffryn]

Thanks Igor.

Since I've had the car I've had 2 services done (20K & 30k), although I only covered 6K during the intervening year. At both services the pollen filter was changed on dealer's advice.

Last service was in Nov 2009, since then the car has completed less than 2K miles, but even so the aircon still doesn't stop the misting up completely.

[peanutome]

Pollen filter changed and air con serviced 3 months ago, then took car back because of this and air con re-purged and filled etc. Still does not stop the steaming up.

Going to try to find the drain pipe and check it for dirt etc!

David

[igormus]

Thanks Igor.

Since I've had the car I've had 2 services done (20K & 30k), although I only covered 6K during the intervening year. At both services the pollen filter was changed on dealer's advice.

Last service was in Nov 2009, since then the car has completed less than 2K miles, but even so the aircon still doesn't stop the misting up completely.

hi mate

i followed the rule to change polen filter during each 10k service whether he wants or not :).

but as you told yours is in order -- it looks like you have to regas the system + check it for leaks.

good luck/Igor

[igormus]

Thanks Igor.

Since I've had the car I've had 2 services done (20K & 30k), although I only covered 6K during the intervening year. At both services the pollen filter was changed on dealer's advice.

Last service was in Nov 2009, since then the car has completed less than 2K miles, but even so the aircon still doesn't stop the misting up completely.

hi mate

i followed the rule to change polen filter during each 10k service whether he wants or not :).

but as you told yours is in order -- it looks like you have to regas the system + check it for leaks.

good luck/Igor

the windshield will never be foggy subject to clean polen filter and sufficient gas weight in the system -- cos all the system + internal air volume in the cabin have beem pre-calculated/designed even on max worse case. so inspect your gas weight and revert with result. now you have :

- gas leak;

- mosture (air) inside the system

as far as i caught your compressor is in order -- right?

cheers/Igor

[peanutome]

Thanks Igor.

Since I've had the car I've had 2 services done (20K & 30k), although I only covered 6K during the intervening year. At both services the pollen filter was changed on dealer's advice.

Last service was in Nov 2009, since then the car has completed less than 2K miles, but even so the aircon still doesn't stop the misting up completely.

hi mate

i followed the rule to change polen filter during each 10k service whether he wants or not :).

but as you told yours is in order -- it looks like you have to regas the system + check it for leaks.

good luck/Igor

the windshield will never be foggy subject to clean polen filter and sufficient gas weight in the system -- cos all the system + internal air volume in the cabin have beem pre-calculated/designed even on max worse case. so inspect your gas weight and revert with result. now you have :

- gas leak;

- mosture (air) inside the system

as far as i caught your compressor is in order -- right?

cheers/Igor

Brand new compressor was fitted last June, been tested and is good. System now purged and refilled twice in the last three months with no loss of gas shown, this fill was to max allowable gas weight. Cabin filter is also almost brand new and clean.

Get plenty of air through the vents, just doesn't seem to be able to dry the air! It can get very cold and hot so cooling and heating part works fine.

Is there an air dryer in the system?

How does the condensor drain the water from the air?

Anybody know how to locate this drain pipe?

David

[igormus]

Thanks Igor.

Since I've had the car I've had 2 services done (20K & 30k), although I only covered 6K during the intervening year. At both services the pollen filter was changed on dealer's advice.

Last service was in Nov 2009, since then the car has completed less than 2K miles, but even so the aircon still doesn't stop the misting up completely.

hi mate

i followed the rule to change polen filter during each 10k service whether he wants or not :).

but as you told yours is in order -- it looks like you have to regas the system + check it for leaks.

good luck/Igor

the windshield will never be foggy subject to clean polen filter and sufficient gas weight in the system -- cos all the system + internal air volume in the cabin have beem pre-calculated/designed even on max worse case. so inspect your gas weight and revert with result. now you have :

- gas leak;

- mosture (air) inside the system

as far as i caught your compressor is in order -- right?

cheers/Igor

Brand new compressor was fitted last June, been tested and is good. System now purged and refilled twice in the last three months with no loss of gas shown, this fill was to max allowable gas weight. Cabin filter is also almost brand new and clean.

Get plenty of air through the vents, just doesn't seem to be able to dry the air! It can get very cold and hot so cooling and heating part works fine.

Is there an air dryer in the system?

How does the condensor drain the water from the air?

Anybody know how to locate this drain pipe?

David

ok it seems you might have two issues:

- condensate remainders under the evaporator ;

- blocked draining tube under the evaporator pocket.

investigate carefully the spot under evaporator -- you must to locacte this tube + even look from the bottomo side of the car - this tube must be vissible as small piece (dia arround 10 mm or so)

cheers/Igor

[Thermal]

How does the condensor drain the water from the air?

I attached the exploded view I mentioned above.

Condensation occurs at the Cooler Evaporator in the interior and drips into the tray shown at the bottom of the drawing.

I suppose the drain hose is connected to that tray and extends either through the floor or the bulk head.

The drawing isn't that clear.

Also check the tray for cracks and dirt and make sure it is fitted correctly under the Evaporator, or else water is spilled into the interior, hence your problem.

Good luck.

[Thermal]

In case you would ask: "Where does the dirt come from that clogs the airco drain hose?".

When the airco is operating, the temperature of the Evaporator is (ideally) ~0 degrees Celcius.

The cabin air that is pushed through the evaporator is a lot warmer and contains a lot of moisture that condenses as water on the evaporator.

That's the drying effect used when you de-mist the wind screen.

The cabin air also contains dust/smoke or whatever particles, that pass through the filters over the years, stick on the evaporator fins and are washed down with the condensed water into a container/tray under the evaporator.

Over time, a kind of sludge will form in that container/tray which will gradually stick to the inside of the draining hose, blocking it entirely in the end.

From then on, any condensed water will be spilled into the interior of the car.

The only good solution is then to clean the tray and the drain hose.

HTH.

[peanutome]

Cheers for the help so far, will try and get to look this weekend!

David

[jimrotts]

just a thought has your vehicle had a windsreen replaced recently

is it possible that the there any leaking seals or body allowing water into vehicle

any moisture in vehicle will cause condensation also check scuttle area clear of debris as if drains block can cause rainwater to collect which then leaks into vehicle

even a leak into the boot can cause smell and condensation

one problem i have encountered is that if people tow using rope without a tow bar can damage seals and body panels

hope this helps

jim