Road water leakage into both front footwells

[Simon S]

My Y reg 3l Coupe has water ingress into both driver (RHS) and passenger footwells. More than just a small damp patch.

This does not occur when the vehicle is static (so not from any of the drains from the windscreen/doors/upper bodywork such as sun roof).

Are there grommets that are supposed to seal  holes in the footwells or some other joins which could have been compromised?

To get the carpet up to investigate further  looks like a bit of an exercise: would it be better in the first instance to get the car on a hoist and have a good look from underneath?

[PaulS]

Most worrying. Not had that myself (from sunroof drains yes, but not road spray which is what I think you mean). 

I suggest starting with a visual inspection with the car jacked up and the wheels off and see what  - if anything - you find.  If nothing, I suggest taping (using good quality gaffer tape) as large a pice of plastic bag as can be fitted without interference, behind both front wheels over the lower body section and going down under the floor.  Drive in the wet again and see if there is any further water ingress.  Check the plastic bag taped seals are still in place and that no holes have developed in the plastic.

That will tell you if it is road spray.

It is also possible that one of your ruled out sources may flex and leak when the car is in motion, sunroof drains are particularly susceptable as the drain tubes (one at each corner)  both block and shrink over time and come off the hidden plastic connectors near the top of the footwell,  I would try pouring water down the top of each corner of the sunroof drains and checking that it comes out in the same volume from the bottom of the car.  This may seem unlikely to be the problem in your case, but it is a quick and easy check....

[Cryistic]

Also look for cracks in the seam sealer where panels join, this would allow in more water than you think.

 

I spent several months searching for a water leak in my old RX, Interior carpets out, boot linings out the works.

 

I replaced all of the light gaskets on the rear of the car, cleaned the Drains out several times when the actual cause was cracked seam sealer where the roof panel joined the side panel of the car, this was letting in a surprising amount of water.  It might be worth going over some of the seams on your floor pan on the out side with some Tiger seal?

 

 

[Simon S]

Many thanks P and Cryistic

I'll get the car on a ramp and have a good poke around. Then if I find anything get going with sealing ideas as you suggest.

The ingress (judging by the wet patch developing in the previously dry carpet) seems in both driver and passenger side to be close to the middle of the footwell (side-side & front-back) of each footwell...