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Discussion Starter #1 (Edited)
Hi,

I've got couple of questions which I believe are may be related to the same issue.

I recently bought a Passat 1.8 B5, and when I bought it the remote locking and electric Windows did not work. I discovered this was due to corroded wires going to the CCM in the passenger footwell, so I repaired the connections by resoldering them and then heat shrinking them. I then unclogged the drain holes (not entirely sure they were clogged to be honest, I didn't really see/feel anything clogging them...)

Anyway, it's been a few weeks and we've had very hot weather, but I just felt the passenger carpet and it's still quite wet.On another note, I also have foam coming out of the vents and so I removed the pollen (cabin) filter and had a look at the (what I believe is) blend door. This is how it looks:

image.jpg
image.jpg

It seems the foam has come off of here and I believe that's what's coming through the vent at leasts. My questions are:

Is this the blend door?
Am I right to think this flaps up fully when drawing heat from the engine, and flaps down to its current position when drawing air from outside?
Could the water in the passenger footwell be due to this flap not sealing correctly somehow?
If not, what could be causing the wet passenger footwell carpet (there's no holes in the body of the car)?
If I wanted to acces the other flaps in the heating system, I have to remove the whole dash. But do I need to discharge the AC also?

Thanks,
James
 

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Are your heating controls (3 knobs & 2 buttons) or Climatronic (automatic, LCD display)?

Are the drains under the battery clear? There should be no water under the battery. If that area is dry, then water is probably not entering via the outside air intake (pollen filter).

There are two other possibilities: the sunroof drains and the A/C condensate drain. The sunroof drains originally had flat sections at the end of the hoses that were supposed to open to let the water out, but seldom did. There was a recall, so those flat sections should have been cut off. Even if they were, the drains can clog at the sunroof, depending on where you park.

The A/C condensate drain can definitely clog. It's not too hard to clean from inside the car. Search the forum for both sunroof drains and A/C drain cleaning.
 

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The blend door directs all air through the heater core when at one extreme and all the air through the AC evaporator when at the other extreme,
and directs some air through each when set in between.
The air is drawn from either the pollen filter or inside the car depending on the position of the recirculate door.
I can't make out anything from your pics, but I expect the flap you are seeing is the recirculate door.

NOTE: The car in this DIY is UK RHD. (the CCM is always on LHS)
VW Passat CCM harness repair | HeadFUZZ

This thread attempts to bring together all the problems regarding water ingress and their solutions.
http://www.passatworld.com/forums/61-b5-information-base/230249-water-ingress-solutions.html
 

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Discussion Starter #4
Are your heating controls (3 knobs & 2 buttons) or Climatronic (automatic, LCD display)?

Are the drains under the battery clear? There should be no water under the battery. If that area is dry, then water is probably not entering via the outside air intake (pollen filter).

There are two other possibilities: the sunroof drains and the A/C condensate drain. The sunroof drains originally had flat sections at the end of the hoses that were supposed to open to let the water out, but seldom did. There was a recall, so those flat sections should have been cut off. Even if they were, the drains can clog at the sunroof, depending on where you park.

The A/C condensate drain can definitely clog. It's not too hard to clean from inside the car. Search the forum for both sunroof drains and A/C drain cleaning.
Sorry I should have mentioned. I have climatronic controls and I don't have a sunroof. I will remove the battery and battery tray today and double check if the drain holes are dry. Thanks for the hint on the A/C condensate drain, I'll look into it, definitely sounds like it could be that then.
 

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Discussion Starter #5
The blend door directs all air through the heater core when at one extreme and all the air through the AC evaporator when at the other extreme,
and directs some air through each when set in between.
The air is drawn from either the pollen filter or inside the car depending on the position of the recirculate door.
I can't make out anything from your pics, but I expect the flap you are seeing is the recirculate door.

NOTE: The car in this DIY is UK RHD. (the CCM is always on LHS)
VW Passat CCM harness repair | HeadFUZZ

This thread attempts to bring together all the problems regarding water ingress and their solutions.
http://www.passatworld.com/forums/61-b5-information-base/230249-water-ingress-solutions.html
Thanks for the reply. If I understand you, the recirculate door and the blend door are one and the same? The pictures I posted are taken of the area below the pollen filter, and that flap there seems to move to either take air from the pollen filter or from somewhere else (I guess inside the car).

I have repaired the CCM harness already (sorry I had a typo and said CCU instead of CCM in the original post). I'll have a read of the water ingress post shortly, that's a great help, thank you.
 

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Since you don't have a sunroof that eliminates that are for water intrusion. The only other two common areas would be the AC drip line or the area under the battery.

There are 2 rubber grommets with little flaps in the middle of the battery compartment. Their painted the same color as the car. They can clog stupid easily with an acorn, leaf etc..When it dries up the piece of whatever that was clogging it can move to another area making it seem like nothing is clogging the drains. I would remove the battery and remove the grommets completely. This allows a bigger drain opening. I took a leaf blower to that whole area and was surprised at all the debris that was hiding up under the windshield area, brake booster and behind the main computer. Periodically check that area and you will have solved that issue.
 

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Thanks for the reply. If I understand you, the recirculate door and the blend door are one and the same? The pictures I posted are taken of the area below the pollen filter, and that flap there seems to move to either take air from the pollen filter or from somewhere else (I guess inside the car).
The two doors are not the same.

The door you see under the pollen filter is the recirculation door. When it's open, air passes through the pollen filter and then enters the heating system. When the door is closed, only a little bit of air moves through the door, and most of the air processed by the heating system is drawn from air already inside the cabin.

The blend door is further down. When the air circulating within the system arrives at the blend door, the blend door sends it through the heater core (at one setting extreme) or through the a/c evaporator (at the other extreme), or through a combination (hence "blend") of both.
 

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Discussion Starter #9 (Edited)
Okay thanks for the answers. I'll definitely investigate the drain holes again, hopefully today.

One more thing, If I have to access the blend door, I realise that I have to remove the dash. However, I cannot find a clear answer on whether I would need to discharge the A/C. So does anyone know definitively if this is the case?
 

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Yes you would need to get an auto AC mechanic to discharge the system. (It is illegal to discharge it to the atmosphere)
You should consider replacing the heater core while you are in there.
 

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Definitely clean the battery well area of leaves and other debris, although I am not sure it will flow over into the air duct easily. If there is no water there when you look I doubt they are clogged that badly.

The pollen filter holder is an awkwardly shaped piece of plastic that is bolted to the firewall. See if you can remove that because there is a foam seal around the air duct that may have degraded. I had to take it all apart once and used some foam tape there.

The AC evaporator drain comes out underneath the car roughly below the dash, which means above the bell housing of the gearbox roughly. I've never had to access it but it is not visible from underneath. You have to remove a heat shield (or two, given the way they overlap, and I believe one of them is quite large). I would tackle that first before thinking about ripping into the dash.

Put some paper towels in the general area where you have moisture and see if it smells of coolant. Then you can start considering dashboard removal.

Most likely some of that foam from the recirc flap ended up in the AC condensate drain. Be gentle when unclogging it and all will be fine.
 

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The easiest way to access the AC drain is to remove the glove box, pull down the carpeting and use some type of rigid material to poke through the drain to ensure the end is open. I have read here in the past individuals do experience large amounts of water being trapped.

I have done the procedure before on my FIL's Passat and seem to remember possibly having to loosen some fasteners also but am not completely sure as it was some time ago.
 

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Discussion Starter #14
Definitely clean the battery well area of leaves and other debris, although I am not sure it will flow over into the air duct easily. If there is no water there when you look I doubt they are clogged that badly.

The pollen filter holder is an awkwardly shaped piece of plastic that is bolted to the firewall. See if you can remove that because there is a foam seal around the air duct that may have degraded. I had to take it all apart once and used some foam tape there.

The AC evaporator drain comes out underneath the car roughly below the dash, which means above the bell housing of the gearbox roughly. I've never had to access it but it is not visible from underneath. You have to remove a heat shield (or two, given the way they overlap, and I believe one of them is quite large). I would tackle that first before thinking about ripping into the dash.

Put some paper towels in the general area where you have moisture and see if it smells of coolant. Then you can start considering dashboard removal.

Most likely some of that foam from the recirc flap ended up in the AC condensate drain. Be gentle when unclogging it and all will be fine.
Thanks for the info, I was actually thinking the water may have entered due to the gasket below the pollen filter housing. When I get a chance I'll remove it and check the seal there.

I did check the drain hole area today and without removing the battery and housing I couldn't see any water around where the drain holes are. Yesterday we had very heavy rain so if the drain holes were clogged I would have expected to see some water around them today, but it looked completely dry (also considering I unclogged them a couple of weeks ago I didn't expect them to be clogged again anyway). I will remove the battery and housing when I have more time and check them properly, I was just having a quick look today to see.

As for the A/C condensate drain, it sounds like it may be the cause so I'll investigate this after checking the pollen filter housing. It does seem logical that some of the foam could have blocked this drain hole.

The only query I have is what may be causing the inefficiency of the A/C in terms of giving cool air. Tomorrow I'll do a pressure test on the refrigerant, but I don't think it's this. Could it be related to a blocked condensate drain by any chance? Ie like with a portable house A/C, if the condensate doesn't drain out of the house via the hose, it traps the moisture with the heat in the house.
 

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Discussion Starter #15
The easiest way to access the AC drain is to remove the glove box, pull down the carpeting and use some type of rigid material to poke through the drain to ensure the end is open. I have read here in the past individuals do experience large amounts of water being trapped.

I have done the procedure before on my FIL's Passat and seem to remember possibly having to loosen some fasteners also but am not completely sure as it was some time ago.
Thanks for that, I'll try it when I investigate further as I already know how to remove these parts, so shouldn't be a problem to access it via this route.
 

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Before you do anything else with the AC system, make sure that the water drains from the evaporator and that it does so through the drain tube. Follow hu's advice and do this via the glovebox.

The evaporator works with air blowing across its fins and if they are covered in water the AC will be very ineffixient at a minimum. After you have verified that the drain works, you can then troubleshoot the AC system for charge etc. Actually you have a climatronic and that has a diagnostic mode with various codes etc. It might be able to tell you more.

If your AC is not working very well after all other external issues are resolved (condenser fin blockages, belt tightness, aux fan working) then you can hook up a manifold gauge and see what it gives you. Figuring out from the gauges if you are low on refrigerant is not trivial save for very low readings. You could have the system evacuated at a garage (they recapture the R134a) and then work on the rest yourseld, or just have them do it all. But only if necessary. I just serviced my AC recently.
 

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jrelder, for me it sound exactly the problem I had and it was due to AC drainage problem. Let this one check and I'm pretty sure you'll find the problem there.
 

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Discussion Starter #18
Before you do anything else with the AC system, make sure that the water drains from the evaporator and that it does so through the drain tube. Follow hu's advice and do this via the glovebox.

The evaporator works with air blowing across its fins and if they are covered in water the AC will be very ineffixient at a minimum. After you have verified that the drain works, you can then troubleshoot the AC system for charge etc. Actually you have a climatronic and that has a diagnostic mode with various codes etc. It might be able to tell you more.

If your AC is not working very well after all other external issues are resolved (condenser fin blockages, belt tightness, aux fan working) then you can hook up a manifold gauge and see what it gives you. Figuring out from the gauges if you are low on refrigerant is not trivial save for very low readings. You could have the system evacuated at a garage (they recapture the R134a) and then work on the rest yourseld, or just have them do it all. But only if necessary. I just serviced my AC recently.
I see, well I just decided to have a look behind the glovebox etc (it's 10:30PM here so couldn't really check the pollen filter housing etc, but I wanted to do something). Now this is what I have figured out so far:

The motors and linkage arms for the climatronic are working (red and blue levers at the bottom behind the centre console).

There is a flap at the back left of the heater housing in the passenger footwell (UK model, so nearest the passenger tyre), that was closed to the cabin first but when I turn on the ignition it opened. This still had the foam intact, no signs of damage. This is picture of the flap I mean, out of interest what is this flap for?

image.jpg

The carpet is wet from the top (nearest dash) down to where it meets the floor of the passenger footwell. After lifting the carpet I can see water on the angle down to the floor of the passenger footwell. I struggled to fully pull the carpet back because it crosses over to the drivers footwell in one piece. But here's a picture to show where I mean (black box to the right is the CCM, left is towards the engine):

image.jpg

I was trying to find the evaporator drain but I couldn't see anything so I'll have another look in daylight. Would I need to pull the carpet all the way back for that? And do you have any advice on how to, considering it crossed through behind the centre console and to the drivers footwell I'm one piece? I'm going to check some diagrams now to see where the evaporator drain is exactly.

I am trying to avoid having the discharge the AC, that's my last resort and if I do have to I will replace the heater core and full check all the flaps. I'm hoping it won't come to this though and I can repair it without having to remove the dash and full heater housing. I'm also planning to buy a vagcom cable this week so maybe I can check for errors using this also? I don't get any errors on the climatronic by the way.
 

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Discussion Starter #19
jrelder, for me it sound exactly the problem I had and it was due to AC drainage problem. Let this one check and I'm pretty sure you'll find the problem there.
It would be great if so! Did you have foam coming from the vents though? Because I'm still trying to figure out where that foam is coming from...
 

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It would be great if so! Did you have foam coming from the vents though? Because I'm still trying to figure out where that foam is coming from...
I didn't have foam though. But other symptoms are the same. During really hot and actually rainy days it got very wet. During hot days it was condensation water and during rainy days it was moisture + condensation. It was really really wet and I was cleaning all the possible places, even used some silicone in some places to be sure. In the end I took my car to the local mechanics and for him it was easy job and he was pretty sure it was the problem.
 
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