Reviving it a little bit😂 got water coming down from above both rear lights, the sealant from factory on the seams is all cracked I'm assuming that's the cause of my leak and possibly around the hinges. What sealant would everyone recommend?

lexal

I was actually going to post my own similar problem then I saw yours.

I've had my 61 plate Focus a few years now and I was getting a little water in the boot before but this year it's got really bad. I'm also getting it in the rear footwells too. 

It's also causing a worse problem now as my boot lid keeps popping open intermittently, bizarrely when I twist the light bezel it can pop open too. I've also just noticed that my number plate light is on dimly constantly with the car switched off and fully locked.

I'm going to wait to see in the better weather if it dries out and the car starts behaving, or if its a different problem. Once the car dries out in spring I'll going to take the rear lights out to see if the seals are shot. Someone also mentioned that these cars can leak from air vents situated behind the rear bumper. Is that correct?

Any help would be much appreciated regarding these issues. 

Read all above. You will see what the issues are and how they are resolved. 

10 hours ago, Oldson said:

Read all above. You will see what the issues are and how they are resolved. 

No I meant more specifically the strange issue I'm having with the boot lid popping open when I twist the light switch and also popping open on its own. 

The reason I put it on this post is I think it has something to do with the water getting in to something electrical. 

here is the problem with the water leaks in the Mk3 models

 

 

Yes, where is this drainage bung in the wheel arch?

 

Hi all, 

Wonder if someone can advise - this large cavity in the boot is now full of water. Found this video on YouTube that has exactly the same issue as me. Unfortunatley no further details on how to fix this was shown. I have removed rear bumper and resealed the air-vents as well as the lozenger-shaped grommets, and I have checked the leaks coming from roof and window, but no water ingress there. I suspect it will be coming from rear lights where the bolt meets the hole - but not sure. Any thoughts? Thanks

 

I had the same problem, got the rear vents resealed through warranty and was still happening. If you pull up the plastic roof rails, there were a few cracks in the paint. Sealed with tiger seal and has been bone dry since.

Had a leak at the top of the inside of the boot door. I reckoned was some bolt gotten loose for the spoiler.

I was right. Issue is the nut on the inside has gotten loose so I can't pull the bolt out and the nut is just free spinning inside. Any ideas on how I can approach it?

I have a Mk3 with water in the boot and rear passenger well...

 

Seen a lot of videos taking about a crack in the seal at the top corner of the tailgate opening and I seem to have this.. So I am going to TIger Seal it and hope it fixes it.

I also plan to look at the rear lights and the vents behind the bumper too.

BUT.. I also have water in the front footwell too.. Could this be the same leak? Is there a route from the rear to front footwells? Or is this likely to be a different leak at the front?

I am gutted as last year I had a windscreen leak which drenched the passenger side and took out my front/left speaker... Although weirdly, a few months after the windscreen was fixed and it had dried out, the audio came back..

So havn't another leak is not welcome!

On 2/14/2025 at 3:53 PM, jweaver said:

I have a Mk3 with water in the boot and rear passenger well...

 

Seen a lot of videos taking about a crack in the seal at the top corner of the tailgate opening and I seem to have this.. So I am going to TIger Seal it and hope it fixes it.

I also plan to look at the rear lights and the vents behind the bumper too.

BUT.. I also have water in the front footwell too.. Could this be the same leak? Is there a route from the rear to front footwells? Or is this likely to be a different leak at the front?

I am gutted as last year I had a windscreen leak which drenched the passenger side and took out my front/left speaker... Although weirdly, a few months after the windscreen was fixed and it had dried out, the audio came back..

So havn't another leak is not welcome!

In my case it was all from the bumper vents. 

The bumper vents void filled and made it's way to the boot, filled around the spare wheel well and also sloshed forward to rear passenger footwell. From there I believe the foam & carpet of the flooring will "suck" the water forward (plus some sloshing if it's bad).

I pulled the full interior out to dry it and dry & inspect the electrics. 

Good luck!

7 hours ago, Schmill said:

In my case it was all from the bumper vents. 

The bumper vents void filled and made it's way to the boot, filled around the spare wheel well and also sloshed forward to rear passenger footwell. From there I believe the foam & carpet of the flooring will "suck" the water forward (plus some sloshing if it's bad).

I pulled the full interior out to dry it and dry & inspect the electrics. 

Good luck!

Thanks.. I am pretty sure my leak is above the tailgate, rather than below as I see water trickling down when it rains.. My plan is to seal up the joins in the body work in the top corner of the tailgate and along the roof channels.. Then look at the lights and seal the vents behind the bumpers for good measure.

I am 100% sure I have a leak at the back... But I am hoping that the water at the front is the same leak.. If not, I have a front leak too which is a nightmare.

Not good for a 2016 car, which has only done 70,000 miles.. Its an ST3 so I have really looked after it, but clearly I am expecting too much.

 

Welp my boot mat underside is all got mold growing on it and starting on the passenger seat carpets and boot sides .

I've used dr beckmans bleach scrub to kill it but I recon I'll have to use some sealant on the vents. There is a wet patch under the fuse panel in the boot (mk 3 focus) and on opposite side, Is this still likely to be the vents (which seems lower?) or just water from the tail lights getting 

I had a 09 focus for about 8 years upon getting this vehicle i had same issue water in the boot spare wheel was drowning lol wasn't the vents nor the lights window seal I found a small pool of water in the plastic trim I peeled back (sat in the boot one day whilst it was tipping down) leading the leak to be a point higher than the screw holes for rear lights from there I was able to trace the leak point I used a bit of silicone sealant never had a problem with that leak again! this leak was coming from the roof open the boot in the rail track there's a fold of metal running down it was a small bad weld spot that was causing the issue I just a layer of sealant there and solved the issue hope this helps 

On 5/10/2015 at 7:43 PM, WES180 said:

Hi 

Edited May 9, 20251 yr by ProfitMouse
Delete, in moron mode!

On 1/24/2016 at 2:45 PM, Bengillam said:

Thanks for the tips just found this in my 2011 1.6 tdci. One question the vent you talk about behind the bumper. Is there one each side? My leak is on the near side but also wet but not as bad on offside.

thanks 

 

I had the rear vent problem which I solved by sealing the vent surrounds. All seemed good to go and then about 2 months later I noticed my coolant level dropping and drivers side front carpet soaked. It turned out to be the O rings in the joints between heater matrix and the engine cooling system. They were replaced and all has been good since. A real bastid of a job to do I am informed.

Edited August 6, 2025Aug 6 by Oldson
spelling

5 minutes ago, Oldson said:

I had the rear vent problem which I solved by sealing the vent surrounds. All seemed good to go and then about 2 months later I noticed my coolant level dropping and drivers side front carpet soaked. It turned out to be the O rings in the joints between heater matrix and the engine cooling system. They were replaced and all has been good since. A real bastid of a job to do I am informed.

If it ever happens again, and it might, (mine failed twice) consider a more permanent solution than a useless little 'O' ring... (Cut an inch off each end of pipe, and replace with a sturdy bit if tubing and jubilee clip)

 

 

2 hours ago, StephenFord said:

Cut an inch off each end of pipe

Sounds like a job for Lorena Bobbitt 🤣

Hi, I recently bought as 2009 estate, yup, water in wheel well. Dried, hose, and pressure wash, no ingress. But left in the heavy rain we just had, it's all wet again. I will be trying some of the sugestions already posted. 

May i say , good informative forum, Cheers.

Does anyone know the part number for the bung on the underside that drains the cavity?

Hey all. Thanks for this thread.

I've just discovered a similar issue in my 62 plate focus zetec. Shopping wet carpet both front and back passenger sides.

Used wet vac and got about 2 litres out Thursday night then same again Friday night. Checked boot and wheel well had maybe an inch of water in.

So I've cleared that out too. I was expecting when I removed the bungs to get drowned but nothing came out on the passenger side and a few drips on the drivers side.

Interestingly and I've read pretty much all posts in this thread so forgive me if I've missed it but there is a wiring harness of some kind (rear parking sensors?) that feeds through the drivers side bung.

Before I (or my mechanic) remove the bumper from your experience is it likely to be the air vents or should I be looking elsewhere?

Pix of other side...

21 hours ago, skotbites said:

Pix of other side...

Frankly not a lot came out of my vents either - until I squeezed the sound deadening material inside.

I haven't done anything else other than remove the material, reseal the vents, and punch a hole in the bungs

and my boot is now dry despite weeks of wet weather driving.

(I actually broke the plastic around the edges of the vents when removing them).

I pulled the paneling off the sides of the boot up to the ceiling / around rear seatbelts, enough to see behind, flooded the lights with water, nothing came in up there so I assume it's all fixed for now