E89 Boot leak

[Rob M]

Just to update this issue....
Taken a couple of weeks but seems water dried up in the rails now.
Did 200 miles last week and no more water pooling now.
Issue now is I have a set of boot vent seals to replace but "chalked" the area and no evidence of water ingress from these, the usual seals, lights seals in fact anywhere!!
Jet washed round lights and boot and also poured water round boot with it open plus blasted the arches.....Nothing.
However the water initially got in I do not know.
Will keep it all stripped for now to monitor but really weird!!




I know there are many discussions and answers on here but I am stumped!
I have 2016 E89 and noticed water under battery tray so duly dried out and also checked light seals/bolt holes and also the rubber seals all round and finally the rubber flap/boot breathers at the side but seems no leaks. Dried up water three times and even blew out with high powered blower and vacuumed out water. Even with no rain, every time I drive water appears, not much but makes foam round the motor wet. I will keep drying out and have most panels removed at the moment.
Found mainly to be behind driver and worst possible corner with all the electronics there but not lifted out all all cable tied in so just blew water out from underneath.
I even noticed white paint on all rubber seals so maybe to confirm any recall or mods performed.
No obvious leaks anywhere and poured (carefully) three watering cans full of water round channels and nothing immediate.
Also hosed over boot and round lights too.
Still not obvious but once in there it travels around I guess?
Can't seem to remove back panel as there are chrome buttons (maybe boot poppers?) that not sure how to remove but water does seems to be travelling along lip under this.

Anyone found water ingress from anywhere else?

 

[Argyll Andy]

You seem to have checked the usual suspects but water can get in, and stay in!!!!

Don’t know if this will help but have a look at Clarker63’s posts in this thread about the water getting stuck in the chassis rails and then reappearing randomly.

https://z4-forum.com/forum/viewtopic.php?p=1911310&hilit=Water+chassis#p1911310

 

[Rob M]

Thanks Andy!

 

[flybobbie]

Been suggested million times, get some kitchen towel and lay as rings around the battery compartment to see which direction it's coming from.
Obviously if that doesn't get damp, the leak is in the well.
Did this on an old car, drivers carpet damp, turned out there was a small pin hole in the seem welding under front window.
Also found a fuel leak in cabin of aircraft doing the same.

 

[Rob M]

[Good idea. Will give it a try. Pulled up passenger side and small pool of water there too so will see and drive around stripped out to see

 

[Nictrix]

The chrome buttons you describe on the back panel are basically fancy bolts and will loosen with a tap of a hammer and screwdriver.

 

[Rob M]

Thanks, thought might be the case but good to know.

 

[warmasice]

Completely strip all trim panels and linings. Get yourself some blackboard chalk (blue/red is best). Create a crossed hatched pattern on all interior metal work. Make sure you draw some around the vents each side of the boot. The water will soon show where's it's coming from as the chalk runs.

This will help you figure out if the water if coming in from around the vents, light seals or boot seals. Just make sure you give the car a good blast with a jet wash including inside the arch lining.

Once you've replaced the culprit you will still have water in the chassis rails. It's gutting to think you've resolved the issue, only to find there's more water. But fear not, I've posted about it too, use lots of tissue and drive around some sharp bends and steep up-hill runs which should get the water out of the rails. The water collects in the area furthest left and furthest right of each rail as you look into the boot.

Finally, place some of those pound shop dehumidifier cartons in the boot for a few weeks to get everything bone-dry.

One more thing...I'd also check to see if the rear light seals are seated correctly. The rubber should lip over both (inner and outer) sides of the sheet metal.

 

[Rob M]

[Thanks, I plan to try everything and driving it 200 miles next few days. I agree water does seems to form at end of the rails but I just cannot see where it is coming in but will try the chalk. There seems to be moisture on the rubber flaps but not leaking even with full watering can poured over the boot seals and lights with boot open! I will persevere....

 

[warmasice]

Honestly I'd replace the vents and boots seals as a matter of precaution anyway. They both use really poor foam gaskets. Chances are that'll solve your issue and be done with it.

 

[javis20]

My leak was coming from a crack in the boot seal. Boot seals are very expensive... Here is what I did to fox the problem...

https://www.youtube.com/watch?v=-0LUeMhHwWw

 

[flybobbie]

My leak was coming from a crack in the boot seal. Boot seals are very expensive... Here is what I did to fox the problem...

https://www.youtube.com/watch?v=-0LUeMhHwWw

That's interesting, my cars ok, but just an observation, i need to look, are there holes in the tube bit at the lower point of seal to let air escape as we close the boot. Might explain water in battery compartment but no where else.

The bottom of rubber would be the last to be compressed as boot closes, therefore logical to put air escape holes there.

 

[B21]

My leak was coming from a crack in the boot seal. Boot seals are very expensive... Here is what I did to fox the problem...

https://www.youtube.com/watch?v=-0LUeMhHwWw

Neat trick

 

[javis20]

My leak was coming from a crack in the boot seal. Boot seals are very expensive... Here is what I did to fox the problem...

https://www.youtube.com/watch?v=-0LUeMhHwWw

That's interesting, my cars ok, but just an observation, i need to look, are there holes in the tube bit at the lower point of seal to let air escape as we close the boot. Might explain water in battery compartment but no where else.

The bottom of rubber would be the last to be compressed as boot closes, therefore logical to put air escape holes there.

Yes, there are 2 slotted holes. One on each lower corner. I believe a replacement boot seal is around $250.

 

[flybobbie]

Yes spotted the two slits when i looked this morning.

 

[warmasice]

Yeh, if unsure save changing the boot seals until last as they cost so much.