Talk to me about boot lids and water ingress.

[Meds]

Hey guys..
Good morning.

I'm starting the investigation into preventative maintenance of the boot lid. In an attempt to hold off any water ingress into the cavity which casuses corrosion from the inside.
I have no corrosion at the moment, no rust appearing around the seam sealer, the 3 drain holes are clear of any corrosion. I've popped the 2 plastic plugs out either side and it looks nice and dry in there. I dont spot anything bad. All good.

I want to understand where I can target to hopefully prevent any issues in the future.

The 2 main areas of ingress that I can see:

• The very top of the boot lid, at the roof. The rear glass seal, each side, allows for water to get underneath, it's not closed. Water will then run all the way down to the bottom of the lid, underneath the seal and collect.

• The same seal but at the bottom of the glass, where the bird bath forms. Can water get past this seal?. I suspect so.

Anywhere else?

Could this be a simple case of being clever with silicon sealant and blocking the top holes underneath the glass seal.
And also, runing a nice clean bead of silicon over the top of the entire length of the glass seal?
This is all reversable and could be a simple solution. If time is taken and done properly, with proper bacteria resistant black (or clear) silicon it could be an option.

Thoughts?

 

[z4pilot]

I personally think the rusty bootlid on these cars is a little like the IMS bearing on 911's - yes some cars have suffered, but it's not universally common and it's become something that people worry about, out of proportion to the risk of it happening.

It may be that it is down to seal failure or a manufacturing fault, but cars that have suffered seemed to have done so reasonably early in their life cycle ie they weren't generally rusty elsewhere.

Your car doesn't have it and is showing no signs of it. I'd be wary that preventative maintenance such as blocking up drain/ventilation holes might actually increase the risk? I'd just carry on with regular checks and make sure everything is kept clear.

 

[TOMGREEN413]

I can't be much help unfortunately, other than the usual inspection for muck and blockages, I'm a firm believer that garaging a car or using a car cover to protect from the elements is essential. Both our e89 and e86 are kept garaged but I appreciate many owners can't. I good quality storm cover is a must imop.

 

[Meds]

I personally think the rusty bootlid on these cars is a little like the IMS bearing on 911's - yes some cars have suffered, but it's not universally common and it's become something that people worry about, out of proportion to the risk of it happening.

It may be that it is down to seal failure or a manufacturing fault, but cars that have suffered seemed to have done so reasonably early in their life cycle ie they weren't generally rusty elsewhere.

Your car doesn't have it and is showing no signs of it. I'd be wary that preventative maintenance such as blocking up drain/ventilation holes might actually increase the risk? I'd just carry on with regular checks and make sure everything is kept clear.

This is good logic

I can't be much help unfortunately, other than the usual inspection for muck and blockages, I'm a firm believer that garaging a car or using a car cover to protect from the elements is essential. Both our e89 and e86 are kept garaged but I appreciate many owners can't. I good quality storm cover is a must imop.

.

Garaging, yes..
My garage was converted to a home office a few years back, sadly.. But a car port is being quoted for and hopefully the build can get started ASAP.!

 

[Mr Tidy]

I think z4pilot is right - it's pretty random.

My first E86 was fine, my second showed signs of it on the bottom of the driver's side and my current one is good for now!

I know some E86 owners reporting getting new tailgates under the BMW corrosion warranty, but it's too late now as it only lasted 12 years.

I've no idea if silicon sealant in those places would help, but I'd love to know if it did!

 

[Meds]

I've no idea if silicon sealant in those places would help, but I'd love to know if it did!

I dont know how we'd ever know.
The very top of the window seal by the roof looks suspect to me, to be honest.
I've seen water holding tight in the bird bath for a long while, I'm sure if that seal was dodgy, it would have started to empty, so I dont think I have an issue there.

What are the rubber plugs on the inside for? Either side towards the rear windows.