Several other threads relate to condensation, but none seem to cover this specific query.

I have had a minor but long-term and irritating problem with a small amount of damp under the rubber mat in the passenger footwell on an Octavia Mk 1 estste.

The problem seems to be caused by condensation on the air-con piping inside the car dropping onto the floor pan and settling in the footwell. There are no apparent leaks through the bulkhead.

It is not rain, I got a small damp patch in blazing heat in France in September - which pointed me in the direction of the air-con.

An attempt to lag the exposed pipes to stop cpndensation has failed.

Has anyone else experienced this? Any suggested cures?

iirc I have heard there can be a problem with an aircon drain pipe, I am guess this might be that pipe. Can you determine if the pipe is blocked?

Are you sure the AC is the source of the problem. If the pollen filter is not fitted correctly then water can enter the passenger side of the car, most likely dripping onto anything underneath before ending up on the carpet. This includes the AC pipework, so check the pollen filter as well.

Or

If the car has had a replacement screen at some point, then its possible its not sealed properly around the edge.

Generally I would agree with you Manny, but as the car was in the south of France in the blazing heat I was assuming there was no rain, and thus poor fitting windscreens, blocked drainage from scuttle area and pollen filter issues were likely to be ruled out.

However if we were talking about the Weymouth this morning, which was like a swimming pool....

Many thanks for those suggestions.

I will look again at the pollen filter. It had been ruled out because the damp problem is not rain related and I understood the filter problem was usually due to poor seating after replacement, and the filter has not been touched this year.

The car is serviced by a small specialist local garage as I gave up on Skoda dealers who varied from expensive and ineffective to downright incompetent. The garage checked the condensor drain pipe and said it was OK. They agree with the condensation diagnosis at present, they call it the 'beer can' effect. They fitted fibre glass insulation to the pipes to no avail.

I have had the car since new. It has now done 112k miles. When it was doing a high annual mileage there was no noticeable condensation problem. Now I have retired and the car's mileage has dropped the problem seems to occur in the autumn when the car has been standing for a few days. I guess the moisture settles in the lowest point in the footwell whan there is no ventilation to draw it out of the carpet.

Apart from this and some other air-con problems the Octavia has been magnificent - including 13 trips to Europe! At 50k the air-com compressor fell off (!) but remained dangling from the pipes so wa undamaged. At 70k the heat exchanger had to be replaced due to a leak, which cost £700 at a Skoda dealer (who then disabled the bonnet release, which I only discovered the day before taking tha car to France).

Performance and economy is better at 112k than new. I prefer to pay reasonable maintenance bills than massive depreciation on a replacement. So I want to keep the car, but would like to solve the damp problem.

Many thanks for the suggestion. Any more very welcome.

Have you inspected the condensation drain valve?

There are two versions, the second being the newer/better. So maybe try replacing it. They can get blocked, or not work if fitted the wrong way up.

Also check the drain pipe is located properly into the drain valve.

It's fitted in the bulkhead, behind a flap of heat insulating mat.

I have posted about this before have a look through some of my older posts.

The grommit/valve in the bulkhead (where the pipework goes through) wasnt making a good seal (perhaps half a mil gap on one side) and it was allowing the water to run out of the pipe then come back into the car down the bulkead.

It is a nightmare to get to and due to the water that sat in my footwell i ended up taking all my carpet out (and most of the interior) including sound deadening to dry it all out.

To fix it i used copious amounts of silicone sealent in several layers to seal the area and have not had any issue since........

Many thanks Bodge and Sweedish for those suggestions which I will follow-up on.

I have spoken to the independent garage who looked at the problem. They tell me:

1. The problem is definitely moisture coming from the area of the air-con condenser.

2. The drain pipe from the condensor is not blocked.

3. But there is a lot of water remaining in and around the condenser.

The car is booked in next Tuesday for an MOT and to have a slightly distorted front disc and its opposite number replaced. I am asking them to check the bulkhead grommet/valve (per Sweedish) and condensation drain valve (per Bodge) as well as resealing the pollen filter (per Mannyo).

The garage also said they will check with Skoda UK. I'm not holding my breath on that one as my experience of Skoda UK when complaining about poor service by one of their dealers was shockingly bad, to put it mildly.

I will update the thread on progress. Googling across the net does find a remarkable number of inconclusive threads about condensation and damp in passenger footwells in similar Skodas and Golfs. I wonder if this problem, which may not be noticed if you are not meticulous about the vehicle, is widespread?

Thanks for the very helpful responses. Any more will be welcome.

Vag cars sadly do leak Peter,

Its common across many of the cars, and i had in my vrs at least 4 definite leaks in different places, i think you hit the nail on the head, if an owner is not fastidious then these things just dont get noticed and just get worse.

I took the opportunity whilst my interior was out to change the carpet to a nice new black one and fit the required wiring for my needs. Its something i seem to end up doing in all my cars and it allows me to check over all the hidden bits so to speak. None the less if i had had to pay someone to do all that work it would not have been worth it......try asking the dealer what they charge to change an airbox or worse still take out the dash.

I had a leak in the bonnet cable grommit (not fitted properly after alarm fitted) area on the drivers side, the rear washer hose in the rear well under the cd changer, the rear pipe to the actual rear wiper motor also kept popping off and leaking and the bulkhead leak i mentioned.

The pollen filter leak seems to occur more in the leon, though i did seal mine properly in with silicone (the base part to the bulkhead) and bought the run off clip (piece of plastic which fits to the front and deflects dripping water from the actual pollen filter itself.

If you take out the fan motor from the inside you can feel under the pollen filter housing (on the inside of the bulkhead) and will be able to tell if the filter or housing is leaking, mine was not.

Regarding the bulkhead grommit iirc there is a tray inside the heater/aircon box where the water from the condensor pools, this should be allowed to run out the car through the pipe into and through the grommit i mentioned and drain down the bulkhead. Once the glove box is removed and carpet folded back you can check access to the grommit see if it gives a good seal. I bought a new one however you cant change it without taking out the airbox as the drain pipe pushes into the grommit after the grommit is fitted and its not an easy job taking it all out.

Hope that helps a bit.

Edited 2 November, 200916 yr by sweedish