Air Con Warm And Footwell Full Of Water

[regdorpten]

On day 2 of a marathon journey to Croatia from the UK and 2 things happened: air con went from icey cold to lukewarm in the space of a couple of hours, and about a litre of water somehow found its way into the front passenger footwell.

I did drive through heavy rainfall for an hour or so but I've done that before and never had a leak into the footwell so I think it must be to do with the air con. It was regassed last summer and I've never had any problems with it. The tailoff in air con perofrmance was so abrupt I can't believe it needs regassing. I'm overnighting a a hotel a couple of miles from a Citroen garage. So anby suggestions before I take it in -- might make it easier for me to suggest a solution to the Slovenian mechanic!

I'm looking at 3 weeks in 30+ temps without air con otherwise....not great when you have a 3 year old in the back

matt

[noz]

Hi Matt,

Whilst the two thing may indeed be connected I can only suggest a cause for the sudden appearance of water. When the aircon is in cooling mode the cold surface of the evaporator which is housed in the heater/fan unit, causes the moisture laden air to condense on the surface. At the bottom of the chamber containing the evaporator there is an outlet spigot with a tube attached. The tube is routed out of the cabin to the underside of the car at the bulkhead just in front of the heater unit. This is where you would normally find a pool of water lying on the road after you had parked for a bit having previously used the aircon. since the evaporator shares the same box as the heater and outside air is drawn in through here the evaporator coil and heater coil can get very dirty. The dirt eventually finds its way down to the drain outlet and can block it. You can unblock it by finding the outlet from underneat the car and poking a wire or similar up the tube to clear the debris.

Whilst writing the above another reason springs to mind which may answer both. Is it possible your heater matrix has sprung a leak? that would explain the pool of water and the release of steam will counteract the cooling effect of the aircon. Check your water level in the header tank. If it is going down then that may be what your problem is. If this turns out to be the case then I can only advise having the matrix changed as soon as possible. If that is not possible then drain the system and fill with fresh water with NO antifreeze. When antifreeze is atomised at temperature and spread through the cabin vents it will cause the car occupants to suffer from heart palpitations and increased heart rate. The glycol is poinsonous when inhaled.

I hope that at least provides food for thought.

Cheers

noz

[regdorpten]

Thanks Noz,

Thankfully there is no smell of anti freeze and last night i discovered that the amount of water in the footwell was greater than the small amount needed to top up the expansion tank.

I shall try to locate the aircon drain and see if it's blocked. water does gather under the car when operating though it semms to be channeled toward the centre of the car and drip own from the general area of the exhaust clamp (the one that the exhaust sometimes vibrates against with ome xm's).

wouldn't explain the drop iff in air con performance though would it?

matt

[xmexclusive]

Hi Matt

Is it possible that the front scuttle passenger side drain hole is blocked.
A collection of leaves or a dropped in washer filler cover are common causes.
Once the scuttle fills up with water it flows over into the passenger footwell going in through the large heater fan air inlet hole. The inlet air temperature sensor is situated in the side of this air inlet. If the sensor is continuously wet it is likely to read and give the aircon a much lower temperature than the actual air temperature. This might just be the cause of the aircon nearly shutting down.

John

[regdorpten]

Just had it regassed to not much effect. Opened the fuse panel and can see steady strema of water dripping through the heater fan unit, which is soaking the footwell when air con in opeation. doesn't smell of anti-freeze but then the water in the expansion tank doesn't relay. Fear I should switch off air con until I get back to uk and discover source.

No water in scuttle. this appears tobe an air con thing

[noz]

Hi Matt,

Sorry to hear that your woes continue. Its not much fun when it hhappens on hliday and you're relying on the car. however, help is at hand.

Sounds to me like you definitley have a blocked condensate drain. Hopefully the attached file will help you understand why.

The evaporator section of the heater box has filled up with condensate due to a blocked drain. When you go round a right hand bend the water is thrown to the near(left) side and enters the casing containing the blower fan. Its not well sealed and eventually leaks out into the passenger footwell.

The reason the Aircon is not working very well is that it is controlled by electronics. The fan speed controller module (bolted to the fan) is currently submerged in water and the wire carrying the speed signal from the temperature controller on the dash to the fan module is shorting to earth (or live) through the water. This is screwing up the datum the controller uses to determine zero for its voltage circuits. Hence the reason it doesn't know if its coming or going.

Take off the side panel from the centre console and shine a torch under the heater box. You will see the drain point in the photo. Either disconnect the tubing here (that might be difficult) or identify the other end above the exhaust box. Clean out the drain point or tubing with a piece of wire. If you drop the fan out, which inevitably you will have to do to dry out the electronics, you may be able to stick a garden hose in the hole in the fan casing and flush the debris out.

I'm convinced this is your problem and as such is possible to do something about it even when you are away from home. Do you have any tools with you or access to some?

Please let us know how you get on.

Cheers

noz

[robertmnorton]

Hi Regdorpten,if the a/c was regassed,did it need gas or did they do a gas recovery and vacuum test before re-gassing up?Is the a/c clutch pulling in?If the clutch is cutting in then you will get cold air regardless of fan operation,just the volume of air is affected.Is the a/c expansion valve inlet pipe cold to touch or showing frost acretion at the bulkhead,engine side?These are all signs of a functioning a/c and you should follow Noz's advice.Good luck.
robertm

This post has been edited by robertmnorton on June 14, 2010 07:11 pm

[regdorpten]

Thank you chaps i'm very grateful for your responses. Have just arrivd at final destination with windows and sunroof open (say what you like about the comfort of air con but its absence does focus the mind on the road ahead).

Noz your comment about cornering provoking the water ingress through the fan is bang on. That's exactly what happened. I actuallhy heard it as a kind of rustling or crackling as I cornered. Then when i stopped it was leaking. It's not constant....I drove for an hour with mediocre a/c performance until it started leaking again.

What is very apparent is that in the past the car dripped water onnto the ground when the air con was on. Now it doesn't. I guess it saves it up then dumps it in the fotwell.

Once I've decompressed from the journey I'll try clearing the blockage and report back.

Robert I'm travelling without my haynes manual and have never looked at the air con before. in fact myknowledge extends as far aswitnessing the mechanic attach the pipes to the valves befoe recharging. unortunately he spoke no englis and me no slovenian so if you could give m a bit of an idiots guide as to what to look for i would be grateful.

[robertmnorton]

Hi Regdorpten,sorry for assumptions,i've attached a schematic of the system.Remember the control functions merely energise the compressor clutch, and the climate control(or the manual selectors) takes care of distribution.The compressor sits under, and forward of the alternator,so looking in from the front watch the pulley.It is constantly driven by the ancillary drive belt, and the clutch end plate will be pulled into the pulley when energised,a/c on.
The expansion valve (or hi press orifice) is on the evaporator inlet pipe.This inlet pipe along with the low pressure return are mounted in a bulkhead feed through on the l/h side,adjacent the hydraulic reservoir.It is here that condensate forms and occaisionally frost if it's humid weather,but should always be cold to the touch with a functioning a/c.On S2 cars the charge valves are located here,on S1 they are on the rear of the compressor.
The schematic gives a real view perspective of the a/c plumbing ,and you will be able to identify the system components with this.The condenser in the front grill,the receiver/drier unit adjacent battery casing,the compressor as previously explained and the evaporator buried in the heating/ventilation unit inside the car,forward centre consol,under dash.
Hope this helps get you sorted.

This post has been edited by robertmnorton on June 15, 2010 07:58 pm

[regdorpten]

Noz & Robert,

I can't open either of your attachments. I'm using firefox on a fully equipped pc but your files are coming up as text-based goobledigook like a page-long expletive. what am i doing wrong?

[regdorpten]

actually it appears i can't open any pdf files on this forum..has always been thus but i'd forgotten. any suggestions?

[noz]

Hmm... sorry about that. It is a pain but it will be solved when the forum software is upgraded.

Right click on the item you want to download and select "Save Link as..." for Firefox or "Save Target as.." for IE. When prompted for the filename and storage path type in "Xm heater box.pdf" or whatever filename you like as long as the file extension (Pdf, jpg etc) is correct. Then open the file from your hard drive as normal.

Cheers

noz

[regdorpten]

Noz and all,

Am I right in assuming you mean the right hand panel of the central console (ie driver's side) needs to be moved for best access. I do have tools but lack a torch and though i have moved this panel haven't spotted the drain pipe. Is it black? You say it may be difficult to remove- why? is it a rubber grip or something else?

Similalry I can't locate its exit point beneath the car and I've looked all over the front half. You mention the exhaust, the heater and the bulkhead. By bulkhead do you mean the front of the driver cabin? I've looked all along the route of the exhaust from exit point from the engine back to halfway down the length of the car. Because the drain is blocked turning the air con on doesn't help because there's no telltale pool on the floor. Does it exit from a hole in the subframe or is it hanging down as a piece of rubed tubing?

And assuming as a result of your response I find both ends of the drain pipe, which would you advise i try to unblock it from - top or bottom? Finally, re wire to unblock it-- is the pipe flexible and curved or rigid and straight ie would a wire inserted from the bottom get far enough up to the top to unblock it completely?

Matt

[noz]

Matt,

Here's a picture of what the tube looks like when attached to the heater box. This photo was taken from the drivers side by removing the side panel. The spigot and tube are not centrally located so they are much more accessible from the drivers side. The spigot is located immediately below the heater matrix. The tube connected to the spiot exits the tunnel above the heat shield for the exhaust. I have been under mine tonight and there is no access to the lower end of the tube. It must terminate above the heat shield hidden from view. The heat shield runs the length of the car. To remove it would mean removing the exhaust and disconnecting the gear linkages from the gearstick. I presume you wouldn't want to do that on holiday.

In which case you are stuck with trying to clear the blockage from the top. There's no jubilee or similar type clip. The grey band in the photo is simply paint. The tube looks like it is simply a push/friction fit on the spigot. Prising it off with a screwdriver looks very feasible. There should be enough length of tube to get the end to turn towards you. I wouldn't think you'd get it round 90 deg without it kinking. At this stage we don't know if the blockage is in the spigot or the tube. You'd need to try stiff wire both down the tube and up through the spigot.

I've been all round my spare heater box looking for another entry point. the only other feasible access is to remove the blower motor which has only 3 screws and I can get my arm all the way in to the evaporator. Thats easy said when the heater box is out of the car. It wil be a different story when its still in the car.

I'm fresh out of ideas now. I hope that helps in some way.

Best of luck.

noz

[xmexclusive]

Hi Regdorpten & Noz

Getting at the drain tube is a 2 minute job.
Just been and checked.
The drain is dead central on the ehaust tunnel about 100 mm engine side of the ashtray. As Noz says the rubber hose of the drain runs just drivers side of the centre line to avoid a fixing bracket for the heater box. This pipe plugs in to a right angle plastic pipe that is cast in the top of a 70mm diameter plastic fitting bolted around the hole through the chassis. The only tool you need is a pair of radio release prongs as everything else is clip fitting so just pushes out.
If you take out the radio (which can be left fully wired to one side) and the plastic blanking tray for the slot above you will be able to see the tube and the end fitting.
I can get my hand in the radio slot to remove, check and refit the drain tube while seeing what you are doing through the top slot. A torch helps to light things up.

John

This post has been edited by xmexclusive on June 18, 2010 10:29 am