Hi all

I've had my Mazda 6 2.2 sport almost 10 years. Its been a great car and this is the first real problem I've had with it so I can't really grumble but hoping someone has experience of this and or can help me....

I have found about 2 inches of water in my spare wheel well and also in the jack storage area.
Using a hosepipe to simulate rain and my wife sat in the backseat/boot area to check for the water I sprayed water on specific areas....
1. On the sides near the fuel filler cap / side windows
2. Onto the rear window so the water ran down the window without going into the side channels
3. Onto the rear lights
4. Ran the hose slowly up each side of the roof drainage channel either side of the boot ( with the lid open) as far as the top of the piston bolts to see if anything was coming though the hatch piston bolts at the top or the rubber pads at the bottom.
5. On the roof just near the middle of the hatch so the water flowed down the drain on each side of the boot but didn't touch the sealant area mentioned below.

The water seems to be draining out down the side channels and out under the car and none of these caused any water to drip in.

I then spotted that there was some kind of sealant just where the roof rails end and the roof panel meets the hatchback panel that had some small cracks in the sealant. I put the hose on the roof rails so the water had to pass over this sealant on its way down the hatch drainage channels.

Even though it took some time (10 seconds) to appear as it is coming out behind trim or panels in the boot some water then started to come into the boot

1. On the passenger side it seems to be coming down the outside of the felt trim about level with the fuel cap and then running down into the spare tyre well (see photo with finger pointing at leak)
2. On the right side it is appearing in the jack compartment where two metal plates seem to met (see other finger photo)

I've also added a photo of the cracks in the sealant.

Please could I ask
1. I know leaks can come from anywhere but could the cracks in the sealant cause this?
2. If it could be this sealant do I need to cut/scrape it out and repair. If so how do I remove it and what should I use to repair it with?
3. I'd like to take the boot trim off the left and right hand sides so I can see more clearly where the water actualy enters but I'm not sure how to remove this hard felt trim or the plastic ledges above. Please could someone advise on how to do this.
4. I managed to use my fingers to pull the passenger rail off near the boot but something snapped so it won't clip back down now, seemed a bit brittle. What is the best way to take the whole roof rail off so I can see if there is any problem underneath them/ give me better access if I do need to reseal the cracked sealant

I would really appreciate any help or advice.

Thank You
Steve

Drivers side cracks in sealant

Drivers side wider view of sealant

Driver side jack compartment where water drips appear

Passenger side sealant cracks

Passenger side where water first appears but its also coming down the inside of the trim

Passenger side sealant cracks with roof rail unclipped

 

If you're still having issues with this, I fixed mine by using flowable silicone sealant in the area either side at the rear of the roof drain channel, after I found a pinhole in the seams there.

 

I think I have sorted all the water leaks!

I removed the rear bumper and rear outer light clusters, and noticed that the locating lugs (for the lights) and the plastic bumper mounting grommets were loose (rubber gaskets had shrunk), so I removed them all and used silicone sealant (paint safe type) to seal them to the body, I also put some sealant under the clip that holds the number plate illumination wiring to the body. I'm now waiting for the silicone to finish curing before reinstalling the lights and bumper. (See attached photo to see locations of fixes - obviously the left side of the car (not highlighted in the photo) was treated in the same way).

In the next few days I will confirm if the fixes described above have been successful.

 

Really disappointing - I've just checked the rear of the car and found water in the left rear recess (behind the wheel arch). Leak seems to be dripping into the front end of the recess, as the rear end is dry (so at least the bumper fixing waterproofing worked!) I'm a bit puzzled about where the leak can be coming from, as I thought I had sealed every possible source. A mechanic friend suggested drying it out with kitchen roll and then spraying the whole panel with cheap anti-perspirant (the type that leaves white marks) so that water track marks can be seen - I've done this and it has crystalised in some places where water is on it, but it isn't clear where the source is - my suspiscion is that it is coming from the left rear wheel arch, i.e. water being sprayed up from the tyre in the wet, as it doesn't get wet inside when the car is stationary and it is raining.

Any suggestions for possible leak areas, that I haven't already mentioned in the previous post, would be much appreciated.

https://photos.app.goo.gl/iSqRBX7CsouHxwYu8 - highlighted area is where the water is collecting (it is NOT wet to the left of the white sealant directly below the vent flaps).

 

Hello!
I'm fighting with this problem for one month.... The biggest issue which i found, but still didnt fixed the problem was leaking from trunk pistons mounting point. I put new seal and tape on screws tread, but its still leaking somewhere...

Cracks on the roof are interested topic for me, i didnt found it in my car, but its time to check..

Leaking from the top to material on wheel.


Here i found one problem

 

[QUOTE=Szmita;240436]Hello!
I'm fighting with this problem for one month.... The biggest issue which i found, but still didnt fixed the problem was leaking from trunk pistons mounting point. I put new seal and tape on screws tread, but its still leaking somewhere...


I think I have now fixed all the areas where the leaks are into the boot. It took quite a while but hopefully my experience can help you -
I ended up pulling out all the carpet and plastic trim from inside the boot to make it easier to see where the drips were coming from - but try these fixes first.

If it is dripping from up high there are a few places you'll want to seal (from your photo it looks like it is, but like mine it might be leaking from below as well).

The first things I sealed (with ordinary, paint safe silicone sealant) were the bolt holes for the boot strut mounting brackets and the bolt holes for the blocks that pull the boot lid closed (further down the side gutters from the strut mounts). This didn't stop the leak in my case, but it is probably not a bad idea, as it is an easy thing to do.

First thing you'll need is some flowable silicone (I bought some of this on eBay - it is expensive but really good, and very neat):
https://www.conro.com/industrial-coa...waAoCnEALw_wcB

Check out this photo for where I put the flowable sealant:

https://photos.app.goo.gl/rto4Si4387q1SGDe8 - Seam (with pinhole circled) - I did the same on the other side (the side that you have a leak on). You might need to remove / prise up the roof gutter plastic covers to get to the front end of the seam in the photo, or you might not, but it isn't dificult to remove them. It takes quite a while for the flowable sealant to cure/dry, especially when it is cold weather - if you can do the job when the weather will be dry for a few days that will make it easier.

I used Gummi Pflege rubber conditioner all the way around the boot seal to plump it back up to create a snug fit (silicone spray might also do this job).
​​​​​​
​​​​​​https://batterygroup.co.uk/accessori...EaAlFGEALw_wcB

You might not need to do the next job if the above one works - I only did it to make sure, because the rubber seal had been removed previously, which might have left a gap in the white sealant.
I pulled off the rubber boot aperture seal (it is a messy job because of all the white sealant in it). I then cleaned off the white sealant residue from the pressed together metal lip that the seal sits on, and ran a bead of flowable sealant all the way around the pressed together part of the lip (it is spot welded not seam welded, so water can get in between the two edges and drip down). It takes quite a while for the flowable sealant to cure/dry, especially when it is cold weather, so what I did was leave the seal off for a day or so and covered the car with a tarpaulin to keep the rain out. Then I refitted the seal.

At this point I thought I had fixed all the leaks - but then I realised it was also leaking from where the bumper is mounted.

I removed the rear bumper and rear outer light clusters, and noticed that the locating lugs (for the lights) and the plastic bumper mounting grommets were loose (rubber gaskets had shrunk), so I removed them all and used ordinary silicone sealant (paint safe type) to seal them to the body, I also put some sealant under the clip that holds the number plate illumination wiring to the body, and around the rear vent flap unit. (See attached photo's to see locations of fixes).

https://photos.app.goo.gl/c5RmUApN4ErrNbfc7 - Left side

https://photos.app.goo.gl/mb656uuJxys3HRwQ9 - Right side

These should fix all the leaks from rain water running down from above, but like me, you might also find the car is leaking from one or both poorly seam-sealed wheel arches - mine was leaking on the left side when driving in the rain, even after I had done all the above fixes - you can tell if this is happening if there is water getting in to the recess on the left side (the same as the one the jack is stored in on the right side) - shown in this photo: https://photos.app.goo.gl/iSqRBX7CsouHxwYu8

You can test this by spraying a garden hose up into the wheel arch and under the back of the car behind the wheel arch liner (be careful not to spray directly at the flaps on the air vent that sits under the bumper). If you do find a leak here you'll need to remove the wheel arch liner and paint on some seam sealer (I just coated the whole area in it to make sure, as I was getting fed up of hunting for leaks!!!!!), you can also put seam sealer or silicone sealant in the inside of the car, at the seam areas.

Another job that is worth doing is to clean out the mud (if any has built up) at the front ends of the rear wheel arches, where they meet the sills - mine were absolutely full of mud and the metal was quite rusty - if you have the same problem with rust You might want to check out a product called "Fertan" - made in the UK. You paint it on and the rusty metal soaks it up like a sponge, it then sets to a hard black coloured surface. I used it on my sister's Renault Clio, where the radiator support frame/cross member was literally flaking apart, and it is now a lot more solid. Fertan Rust Converter

Hopefully this helps you, and saves some of the messing about that I've had. Please let me know if it works.

P.S. The last bit about the seam sealer has still been going on until last weekend, as I found a tiny amount of water in the hard to reach area behind the wheel arch, forward of the air vent flaps (red arrows point to it in photo) - so hopefully the second coat of the seam sealer that I put on at the weekend, has fixed it (I drove in the rain today for the first time since treating it and I can't see any water inside!)
https://photos.app.goo.gl/knXfPLUx7bj9iF8J9

 

Woo, you did a lot of work.. Thanks for great solid answer! I will try to follow your steps

 

Yeah, it has been a bit of a saga! No problem at all - I hope you get the leak(s) sorted out.