I too had a bad experence with water leaking into the trunk. Had to replace the Park Aid-Riversing Module which suddenly caused beeping when cars got close behind, while driving forward. This happened right after a downpour of rain. Pretty pricey item $250 at dealership.
After purchase, I noticed the Ford part #on the box 02XR845141 which is different from the #2R83-15K866-AA on the actual unit. So, this item could be purchased for less from another source.
Also, the parts guy at dealership mentioned that Jaguar has changed Trunk Rubber seal suppliers 5 times since 2002 due to leaks. Apparently this is very common on these cars.
Following these threads, I removed the rubber (which seems to be in perfect shape) applied a bead of Silicone to the trunk lip & re-seated the seal. I also applied some around the tail lights. Have not noticed any ingress since, but will keep checking after each car wash & rainfall.
Thank you all for sharing your experiences.

 

As an Oregon resident, I'm on close terms with the rain. My '02 S-Type had the infamous trunk leak, and rather heavy I might add. I was surprised how much water could make it in the trunk. I found water tracks on the interior side of the trunk seal, at the base of the angled corners at the back.

At first glance this made absolutely no sense, as water would have to go up and over the metal lip on which the seal is installed. However, think about it from the perspective of a water drop. Imagine water running down the back window and entering the trough on the exterior side of the seal. While the bulk of the water will stay on the exterior side of the seal, some will migrate inboard by capillary action. This water, now trapped by the seal on the outboard side of the metal lip, will basically follow gravity's pull and head aft until it reaches the back corners. Here the seal inadvertently blocks the water from escaping, so it goes up and over the metal lip and into the interior. Just where you'd want the seal loose against the exterior side of the metal lip so any trapped water could escape, it fits extra tight because of the way the seal bends around the corner.

My thoughts are if you see water at the back corners, it may look like it's coming from the taillights. Perhaps there's a combination of the two. All I know is I had a major leak and the only thing I did was replace the trunk seal. No sealer used anywhere and I never touched anything else. Two years later in Oregon, and it's still dry as a bone. YMMV.

 

Failing trunk seals appear to be the main culprit, but some owners have in fact detected water leaks at their taillights as well. So I reseated the trunk seals, then made some rubber "grabbers" that serve the purpose of pulling both taillight assemblies tighter against the rear panel they mount on. Like you, I've seen absolutely no water in our S-Type's trunk since taking this action several years ago....

 

I can't believe I'm posting this, but after years of dealing with this water ingress business in S-Types, I have learned to deal with this a bit differently. As many of you have found, this repair works for guy A, that repair works for guy B, and yet something else seems to help guy C,D and E. My experience has shown it will always return at some point no matter what you have done or tried.

I treat the S-Type trunk like a sunroof. Your sunroof seal is not there to keep water out, whether you realize it or not, it is there to reduce the water entry to a manageable level. That manageable level can then be carried away by the four sunroof drains. So let's reduce the task of the trunk seal accordingly. Make it right, and if a little water gets by, it's only a tire well after all, make a path for what little water gets in to get out. Look under the trunk well, right in the center, there is a grid of holes in the floor pan. All those holes are sealed by a rectangular tar pad. Put a small screwdriver through one of the holes and open it up to the full diameter, it's really easy to do.

From now on any moisture that gets in can get out, and you will never know it was there. I hate it, but it has been the only final repair that I have never had to address again, under any circumstances.

Just my two cents.......

 

I'm the 2nd owner of my 06 S-Type and have never seen water in my trunk. But it's obvious that hole plugs have been removed from the trunk floor because their outlines can be seen in the form of missing paint surrounding the open holes.
On the other hand, I have had enough water get into the plastic chrome strip across the back edge of the lid to detach the metal foil surrounding the push button on the underside exterior of the chrome trim piece and cause algae growth inside the license plate lamps.

 

Hello guys.
When I removed the perfectly good looking rubber seal, I noticed the rubber weld was at the top (center of the trough), that part of the rubber is week & irregularly shaped where water could start jumping over the lip. So I rotated the rubber bringing the weld to the bottom rear edge of the trunk lip. Applied a bead of silicone to the lip, squeezed the entire length of the seal prior to re-seating it.
Adjusted the black threaded supports, leveling & tightening the trunk on the seal. Also, as an additional precaution, removed the two floor plugs at front & rear of spare tire.

 

I have a 1999 S-Type and I have stopped the water leak as follows. I completely removed the rubber seal that circumvents the whole boot. This was not difficult and I managed to remove it from the car by pulling it over the boot lid. Under the rubber seal was all kinds of 'grot', ie. road dust, composted leaves, spider web, loads of old mastic and debris. Using white spirit I cleaned the raised metal seam over which the rubber fits. I then cleaned the underside of the rubber seal with hot water/washing up liquid using a stiff nail brush and small screw driver. I then stuck a length of black electrical insulation tape all around the boot over the raised metal seam. This allowed the rubber seal to go back on nice and easy and firmly. After I had replaced the rubber I used a small amount of 'Capt. Tolley's creeping crack cure' (available on line) and hay presto, NO more leaks since I did it a month ago. One other tip that may be useful, when I replaced my rear number plate I found 4 old drilled holes behind it. These holes feed straight into the boot and with the 'airflow' from moving forward I have no doubt that in heavy rain this water would have been drawn into the boot either side of the boot catch.

 

JFYI... everyone knows that one right?
just for your information. My car had a leaky boot, I felt for a dampness after a rain and dicovered that the fender top seam near the passenger side boot hinge had suspect tightness so in that painted channel just outside of the boot lid gasket I smeared some goop in that crack and walla... no more water last I checked.

 

OK, so not to discount all the explanations above but this is my story and solution.
04 S type, small amount of water collected in the bottom of the boot (trunk). The seals had already been siliconed and the issue only occurred when the temperature dropped. I found that my boot/truck vent was blocked, unblocked the vent no more leak If your boot is sealed and the temperature drops the pressure inside the boot falls and it tries to suck in air. If the weakest point is actually a flooded area you suck in water. e.g. the channels round the boot/truck lid.
So my 2c , check the boot vent is clean

 

Sorry but the trunk is not tightly sealed to create a vaccum in any conditions and depending on conditions water does not go up hill. Check for the obvious along with opening one of the plugs to drain.

 

I hope the vent you mean is not the battery vent - which should have tubing all the way to the battery itself.

+1 the boot isn't a sealed place and also it should not have water getting in.

 

On my first S-type (2004) I had water in the boot but cured it completely by putting a bead of sealant along the top edge of the tail light units.

Never had any more trouble after that.

 

Thanks for this, you just saved me weeks of heartache on my cat. My leak was a combination of the boot seal and the bumper bolts coming loose. Stood there pouring water on it to find all the leaks, but you pointed me in the right direction. Re-tightened the bolts and leak has stopped. Thanks!!

 

I've got it too on our 2001 Y reg Sport in 2013. So will give all or most of these a go thanks guys and dolls one and all.

Cheers

Derek

 

Great car despite some gremlins. But no rust unlike your average Mercedes.

 

Unfortunately I have tired all the suggestions below and when it rains heavily I get a lot of water in my boot and am really worried about all the electrics in there. Any other suggestions appreciated guys

 

Talc or the like to see exactly the path it gets in.

Or get in with a torch and have someone use a hose then watch where it gets in.

 

Did anyone mention to get right in the trunk with a flashlight and have someone hose it ? It's what we had to do in the Ford garage if we had a leak on warranty.

 

2001 S Type just started having the same problems so have siliconed the seams near the rear lights and the gaping holes just above the corner of the lights.
Interestingly , with no rain for a few days I was feeling above both these points on the UK driver's side in the area behind the boot spring. It feels damp there still. Condensation or ingress of early morning mist?? I did also put some silicone on the seam in the channel just below the corner of the rear window. It will rain soon enough to check progress. I just know I will be going in the boot but am relieved the remote has a boot opening button and the rear seats fold back!!


Mike.

 

Can anyone tell me the part numbers for these boot grommets? I have a leaky boot.