Weird water ingress issue

tchalikias

Paid Member
So I've noticed every time after I wash my 200 that water accumulates in the footwells, both driver and passenger sides.

Originally I thought the culprit would be the drainage pipes behind the front scuttle panel. They were indeed clogged and I cleaned them thoroughly. Water no longer pools there.

However, the problem persists. Today I sprayed the front of the car with a gardening hose to remove a couple of bird droppings from the windshield. After half an hour, I looked inside the car to find both mats wet.

I've ruled out water coming in through the a/c by placing a plate beneath the driver's side footwell vent. No water seems to drip from there. However I can't for the life of my pinpoint the point of entry in the cabin.

All I know is the area under the mats (driver & passenger's) gets really wet after a wash or heavy rain. The surrounding area seems to be completely dry (i.e. the carpet behind the pedals is dry, as is the firewall etc.)

Thankfully being summer the car takes a day or two to dry out completely. But during winter this will pose a much more serious problem.

How should I go about discovering the water ingress point? This did not happen when the car was new, so it must be something that has deteriorated over time (a seal behind the bulkhead, perhaps?)

Thanks in advance for your ideas!
 
I used to get this in my previous car after a heavy shower, the water ran down the a post and leaked through the door seal, it gathered at the bottom of the seal then overflowed into the car. To cure it I took a sharp blade and cut a 2mm strip from the seal so it just ran onto the sills and out onto the floor, not a fix I know but It did keep the water out
 
folding mirrors can cause water ingress if you have them.

also look underneath the doors and check the drain holes are clear. You may be getting trapped water in the door.