Water ingress at rear footwells

[bobthevoice]

Hi guys, my K reg Cav has had water ingress into the rear footwells. the first time was one week ago and i mopped up 90% of it hoping it was a one of drama.so one week later and there was a lot of rain and today i had a look to find that the rear footwells where soaking again.i looked at the front footwells and they are perfectly dry as is the boot.so the question is this.is there any known or common areas i should look at to identify the cause of this water ingress.my brother uses this car and his health/mobility is pretty poor so i would like to sort this for him as he cant be involved diagnosing/fixing the issue due to poor health.any help would be much appreciated.

thanks guys.

Bob The Voice.

[Cavalier342]

Are the rear footwells completely wet from corner to corner or are there any obvious signs at either corner, near doors, etc? This time of year, once carpets get wet, they don't tend to dry out, so the problem won't go away unless the problem is cured and carpets/underlay are thoroughly dried.
First check the door seals and windows, make sure nothing is getting through them. Could be sunroof drains are blocked, but you'd have to remove the inner trim behind the seatbelt anchor points and headlining to get access to them I think.
Also if you can, get underneath and check for any obvious large rust holes, if there are any, moisture loves to get inside and stay there.

[Robsey]

Andrei has asked all the usual questions.

The Underside / Chassis.
1 - Chassis Condition - There are rubber or plastic "bungs" in various areas of the rear foot-wells that work well when in place. But if any are lost or dislodged, then this leaves a hole in the underside for road spray to be flicked up into the under-felt / foam layer, which acts as a brilliant sponge sucking in the water.



2 - A common rot-spot on the Cavalier is the sills on each side, but also the rear corners of the foot-well section. There is a sharp 90 degree bend, which can rot out over time, giving the same issues as the missing floor plugs / bungs.

2b - Rear Inner and Outer Arches can and do rot out over time, possibly allowing water to be flicked into the rear of the car.
There is also a sponge insulation block just above this area, which reduces inter-panel wind noise, but also acts like a fabulous sponge. Most restorers remove this foam insulation to remove a potential source of moisture collection.

Sun Roof Drains
3 - If you park in close proximity to trees, or near a lot of building dust and muck, it is possible that debris can build up in the drain channels of the sunroof or their drainage hoses.
When blockage occurs, this obvious causes the rain water to back-track and make an alternative bid for freedom through whatever route it can find, even between the layers of the body shell.

Door Seals
4 - Possible, but not very likely in my experience. I have a very weak door seal, which allows a lot of wind noise into the cabin, but so far the car has been bone dry inside.
If a window or door has not been closed properly then driving wind and rain could cause the rain water to be blown into the cabin area.

The only way to find out, is to do a chalk or talcum powder check.
Remove the rear seats and the rear carpets. (there is a join between front and rear sections below the front seats.

Then when you have done this, look for a browny-red staining that would indicate rusty water entering the cabin.
If nothing is too obvious, get some talcum powder or powdered coloured chalk, and scatter this all around the now exposed rear seat bench and foot well area

In this glorious weather, it should not take long for wet streaks to form in the chalk powder indicating a route or source of your dampness.

A Totally Random thought if you have a hatchback.

A totally random thought, but not impossible is a damaged rear washer hose as it flexes between the rear hatch and the right hand D pillar. If the pipe is damaged as it leaves the D pillar, or the rubber grommet / sleeve is not sealing properly, this could cause water to enter the cabin down the driver's side D pillar and into the rear foot-well section.

[bobthevoice]

Thanks Robsey i'll talk to my brother so see when we can start a strip down and investigation.

Bobthevoice.

[cavalier1990]

Bob, make sure boot isn't leaking which can find its way down to rear floors, cavalier notorious for leaks from many places as mentioned, fixed most of mine, which were the floor bungs, rear floor boot rust, back quarter windows on my old cav leaked also. The insulation on front is really thick and it can take longer to soak through to carpet, but can run into back where it's thinner and soak into carpet quicker, so may still be coming from front. If you're struggling to find I could have a look.

[bobthevoice]

Cheers Andrew, I hope to have a look in a couple of days and see what i can find.
Weather permitting, I'll get back to you and thanks for the offer of help.
Hope all is good with you.

Bob