Wet carpets - where is the water coming from?

the title says it all - i've discovered my passenger side carpets are sopping wet on the underside, the water isn't coming in through the window/hood interface as i have been keeping an eye on this, and the top of the carpet is dry, but the sponge on the underside is wringing wet. it's worst at the front of the footwell.

I'm trying to find where the water is coming from, does anyone have suggestions on the most likely point of entry? My initial thoughts are either through the seam where the floor meets the sill, or running down from around the door pillar / wing/ screen interface.

Heater air intake...?

Good point i'll check , but i sealed it when i fitted my servo bracket, so shouldn't be leaking.

Do you have aircon? If so, check the small rubber drainage tube that disappears from the main air-con unit on the passenger side through the floor. It is so small you can hardly see it due to the carpet.

Have a look at the condition of the large blank grommet to the right of the snorkel. I found a line of corrosion around mine that had lifted the grommet seal and allowed water to seep through. I cleaned mine up and run a circle of touch up paint around the hole before refitting the grommet.
The top of the carpet will be dry as there is a plastic skin between the top of the carpet and the foam underside. Any water collecting on the top of the carpet will naturally dry up through evaporation, however any finding its way under will never dry out because of the plastic membrane.
To dry the carpets I lift the carpets back and squeeze out most of the water and use a fan heater to dry the foam out.

Sundance

So i've just been out in the howling gale we have here at present, took out my glove box and stuck my head down the footwell - yes, looks like the air intake, also the air intake duct has come away from the 'snorkel'. so that needs sorting.

At the moment i'm stuffing towels under the carpet to soak up as much of the water as possible, from past experience the best way is to take the seats and carpet out, the carpet sponge dries best if hung up to dry, and the car is coming off the road at Christmas anyway so that I can fit my Christmas present - four new wheel bearings :woohoo:

Took the air intake snorkel off, removed the soaking and compressed foam and used a non-setting mastic to seal the snorkel - hopefully that will stop the leak. Used this https://www.everbuild.co.uk/product/115-gp-building-mastic/

My TF has the same symptom as this. How do I get to remove the snorkel to reseal it please. Is it somewhere under all the black boxing under the bonnet or under the scuttle panel please ?

This is what your looking for the "snorkel" shaped thing directly behind the brake servo, if you have a much larger squarish box (early cars) these were more prone to leaking and many have been swapped for the snorkel one. If you know the name of something just google MGTF ???? then click images and you get lots of pictures which will help locate it, that's how I got this.

Ah I cant see that on my TF, The whole area is covered by wide black plastic boxing. Not sure if thats normal and should be refitted when i check the snorkel or most people discard the plastic cover ?

The plastic cover comes off easily, if I remember (unlikely) there's just a couple of clips and plastic nuts, it's so easy to come off (about 10m) and replace that I would keep it, it protects things from muck thrown up and makes it look neater.

To remove the cover.
1 is a plastic scrivet. 2,3,4 are plastic nuts.