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Discussion Starter · #1 ·
OK my just bought 2.3T CSE has this new fangled (to me) ACC. Problem is if I switch to ECON the windows very quickly mist up, with AUTO on everything is OK. Question is have a got a weeping heater matrix?
Even if I have still think car was a bargin - £3800 for a 97 auto, 98k 1 owner and just got the Saab service history print out from Westbury, HPI completely clear.
 

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My 2001 VW Passat has Climate Control and has done this sort of thing from new.

Don't know if it's something you have to get used to - there's problem something you can do to clear it - though on the Passat - being a company car, I'm not bothered about the fuel consumption so the Climate is always set to Auto - and thus I've not tried to work out what to do.

I'll be interested in the responses though...


Kevin Mc
 

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had a steaming up problem with a 97 cse. The heater matrix was replaced, it was weeping anyway but it didn't solve problem. It turned out to be air recirculation motor u/s and stuck in recirculate position, so air in car got stale and damp. A quick way to prove this is to remove the false bulkhead top covering at rear of engine comp. Remove the letter box size cover that allows access to pollen filter. This will now let fresh air into the chamber. Drive it about and see if it makes any difference. Don't worry about the cold draught you will now get on your knees at speed! If this clears windows up, you'll need a recirc motor replacement.
 

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Adrian
That's partly normal, depending on extent of misting up. With the ACC on AUTO the air-con compressor is running so effectively de-humidfying the air and therefore preventing the windows misting up. With the ACC on ECON the air-con compressor is switched off, and therefore the windows are very likely to mist up as they would in 'normal' cars.
 

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Discussion Starter · #5 ·
The windows are misting up badly even with a window open (even on a nice warm day), definately worse than a 'normal' car.

Where is the recirculation valve? Is it easy to get to? Was there a previous thread on this?
 

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ACC (or A/C) will definately cause the front screen to mist up more than a normal car.

Once the aircon pump has been run, water will collect on the cooler (i.e. because it dehumidifies the air, as well as cools it). So, when aircon is turned off, the air passing through picks up this water which then condenses on the windows!
I would hazard a bet that this is what you are experiencing Adrian!

As I generally run my car without the aircon on, the windows do NOT normally mist up. But if I run the aircon for 10 minutes, then turn it off, the front window will almost always steam up - certainly for the first minute or two. The situation is always worse if it is raining or there is high humidity levels outside. If the outside air is quite dry, the misting window effect should clear quite fast with the aircon off and the fan on a medium to high setting.

The above is 'normal' for Saabs with A/C or ACC, and most aircon systems on cars.

But if there is loads of water vapour, and it smells warm and muggy and like antifreeze (cos it is!) then the normal cause is the heater matrix leaking. Apart from the smell, a heater matrix leak can often be detected because the aircon (when turned on) takes a lot longer to clean the mist from window.

If the recycle button is on, or the flap is stuck, it will also cause general misting of all windows to occur - but without the antifreeze smell (i.e. heater matrix not leaking). But such misting normally takes alot longer to build up than if caused by water having condensed on the aircon cooler (due to aircon), or a leaking heater matrix.
 

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Discussion Starter · #8 ·
Thanks for the tips Paul, I'll have a play this weekend and see how things go. Did think the car smelt of antifreeze when the windows were misting (but probably paranoia). This morning I had the ACC on ECON as soon as the car started and only a very slight sign that windscreen was misting by the time I got to work (10 miles later). Might slap some radweld in this weekend (OK I know but I did this in my Carlsson and its been OK for 3 years).
 

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I think the price is what is realistic. A few weeks ago a friend purchased a N-reg 9000CSE with wood/leather/alloys etc, one owner from new, FSSH etc. Mint motor and he payed about £3,400.

A lot that are advertised are way over the mark.
 

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FWIW, I think Paul is right. My old mondeo company car used to do this all the time if switching from air con to normal on slightly damp days. It also used to smell very musty if used after a long time without. My cse used to do this and so does my aero, both with no water loss or leaks.Admittadly, it wasn't quite the sauna effect you seem to get but it was enough to obscure vision. I never run mine on aircon in winter unless it is exceptionally damp.Seems as if condensation builds up, but this should soon clear.
HTH
Anthony
 

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Discussion Starter · #11 ·
Well I got home tonight (with ACC off) without any misting so looks like Paul was right, excellent.

Yep John I guess realistic is probably a better description, at least thats what I was prepared to pay. North West Saab (I think part of St George) had an identical car but little turbo for £5995 + an identical car but R-reg also for £5995 and they wouldnt even talk at £5500! Hence I got mine from a different dealer. Like you say people just seem to want too much (good luck to them if they get it though)
 

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The air con evaporator box has some drain holes which drain into small rubber tubes which then pass the water through hole(s) in the bulkhead which then falls overboard.
This is why you sometimes get a clear damp patch under the car after shutdown on a hot day.
Anyway if these rubber pipes become clogged then condensed water would collect in the air con evap box and cause the misting.
Just an idea?
 

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Discussion Starter · #13 ·
Thanks for the info, tips and help. Paul was right. As long as the aircon is not switched on there is no misting. If aircon is switched on for say 5 to 10 mins and then switched off the windows mist up, but it clears after a few minutes. I've no programmed the ACC to switch on in the ECON mode.
 

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Discussion Starter · #15 ·
Basically set the system up as you want it i.e. ECON on, select which vents you want open and temp and fan speed then press 'two certain buttons simultaneously' (will need to read handbook to remember which ones). The ACC display and LEDs flash to say its been programmed and next time you start the car hey presto its as you set it up. See handbook for details.
 

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To programme the ACC unit, first set it to all the settings of temp, fan speed, and direction of airflow and whether auto or econ. Then you need to press the windscreen airflow direction button(top right on mine) and the vent button at the same time(bottom right on mine).As the book puts it, the ACC display and LED's start flashing.As the book also says "you must wait at least 4 minutes after switching off the ignition before you can test the programme functions"

HTH
Anthony
 

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I think Saabpilot might be right about blocked drains. Your symptoms appear way worse than I would expect. Yes, water does condense on the evaporator but most of it should drain out and I would be very suprised if a normal system misted the screen on a warm day. I've had problems on cold, damp days (had to run the aircon AND the heater!) but never any problem on warm days.

If I remember correctly the drain pipes drain into the bottom of the area behind the false bulkhead (I heard this called the aquarium as blocked drains are very common!). From there it drains out via a 1 inch diameter pipe with a flap covering it. If rubbish (leaves etc) gets into the bulkhead area then the drain blocks. Definitely worth a check anyway, only 5 minutes work.
 

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There is a four inch flexible plastic drain tube which needs to be refitted into a hole in the base of the 'aquarium' area, when jobs like a replacement heater matrix are carried out. If this pipe has been kinked back on itself (for example) it will cause the drain hole to block, and compound the window misting problem. Otherwise, the area below the false bulkhead should be sealed (as air should only come in via the cabin filter!), so it is not common for the drain hole to block.

Don't forget, that warm air holds quite alot of moisture. Only below 0C, is the air actually 'dry' (and the aircon doesn't work below 4C anyway). Most normal days the air contains approx 50% humidity. (NB: 100% means it's raining!)
 

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not sure I quite follow you Paul.

On mine ('93 CSE) the evaporator unit sits in it's own box along with the cabin filter. This has a drain pipe which runs down to the bottom of the aquarium. By aquarium I mean the whole area behind the false bulkhead which houses the heater, wiper motors and ECU etc. There is a second drain from the bottom of the aquarium (just where the evaporator drain pipe ends) which I think had a rubber flap valve on it. On mine, small leaves/dirt had blocked this vent causing the aquarium to get damp and also stopping the evaporator draining properly.
Not sure how the leaves got into the aquarium area but I thought the cover has vents to allow air to the cabin filter housing?

Toby
 

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btw. when I said I thought it unlikely that the screen should mist on a warm day I was assuming a warm UK day. To get misting you need the vent air temperature to be higher than the screen temperature and to be reasonably close to 100% humidity.
 
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