[casualDIYer]

It's time for an update. As posted on June 19 the initial results were very good. Most of the creaking was gone. I'd rate it as 95-97% gone. As of Aug 31, 2.5 months later, here is what is happening.

The 3 passenger doors (rear x 2 + front passenger side) remain silent. The driver door has started to creak a bit but only in a) hot weather, b) when the car engages in high degrees of flex such as entering or leaving an incline, and c) to a moderate to low degree. The driver side door rarely creaks during normal driving, even when encountering uneven pavement (pot holes, road cracks, sewer grates). Even when it does, the creak is somewhat muted.

Guessing, I believe the creak comes from the window guide expanding under heat and sticking to the black shadowline just like a tire sticks to the road as it is heated. The reason the problem isn't immediate when a car is new is likely due to a moulding compound using during the window guide manufacture. It would take quite a few door openings and closing or use of some sort of cleaning chemical to remove the compound. The compound may also break down over time, again, mainly due to exposure to water and dirt that would act like an abrasive and rub it off.,

The moleskin tape may start to collect contaminants as the door is opened and closed, reducing some of it's effectiveness. As the other 3 doors for passengers are rarely used, they remain mostly silent. I will try cleaning the shadowline trim to see if that helps. Given the creaking is occasional, I will continue to test this solution. With fall-winter coming, there is going to be a creak holiday for about 6-8 months, after which I may re-apply the moleskin tape or try another method. I've recently discovered that Xpel Ultimate is a visually superior, easier to install type of PPF and may move to using that as an alternative.

For now, moleskin while not perfect, remains a highly effective, easy to apply, solution, that anyone with access to a pair of scissors, a non-silicone based cleaner, patience, and common sense can apply. If you are doing a job that allows you to buy a BMW, you're qualified to give this a try. Just as a review here is the latest update

BMW Window Guide (sometimes referred to, incorrectly, as a window seal) - Shadowline Creak Solutions
1. Replace the Window Guides
100% effective for getting rid of the creak.
Expensive (~USD$100+ per door)
Hard to install. You will need a special chemical to install the guide
Lasts 1-2 years

2. Swap shadowline to chrome trim
100% effective for getting rid of the creak
Expensive (~$1000 for new parts)
Harder than it looks (you'll need fingers of iron to pry off the trim, be careful to NOT scratch your car, you'll need new plastic clips)
You'll likely hate the look of the chrome trim
Lasts years

3. Coating the trimline with teflon film
100% effective for getting rid of the creak
Way more expensive than you'd think. Used in industrial machines on rollers, a roll of genuine 3M teflon tape is ~USD$250
If you are not a klutz with tape, you'll be fine installing this yourself
Will last for a year or so

4. Coating the window guide with moleskin tape
95-100% for getting rid of the creak depending on door
A moderate cost, roughly USD$40-60 for both sides of a sedan
If you can use scissors and not cut your fingers off, you can do this yourself.
So far, effectiveness on less frequently used doors remains 80%+ On doors hardly used, effectiveness is 95-100%
No data on how long the solution would last beyond 3 months. Note that creak, when it does occur, is somewhat muted, as the one goal for hush tape is to reduce sound

5. Using PPF or similar polycarbonate films on trimline
I've spotted some reporting 100% effectiveness
Not much data on longevity
Polycarbonate tape comes either in a 'sticky tape' format, where you apply it directly to the trimline without any other chemicals or PPF format, where you need a slip solution (water + baby shampoo) to apply it.
I couldn't find a lot of info on PPF but guessing, the PPF, if it worked well, would likely last quite a while as PPF is quite durable. Cheap sticky tape likely would last a lot less
Applying PPF on a flat surface is easy. On curves? This is why the installer is getting $500 a panel when he puts it on your car. Watch a lot of YouTube and be patient. Suggest Xpel Ultimate Plus as it is visually appealing (very good clarity) and easier to apply than some competitors.
Vinyl wrap may also work as it was used in the past to hide chrome trim
The key to PPF? Clean that trimline with panel wipe, a cleaner used by body shops to remove chemicals from surfaces they plan to paint.
Cost for sticky tape is cheap USD$10-$20. PPF, when bought in a length. you need roughly 16ft long x 2 inches wide for a 3-series sedan. Should be about USD$40 plus a can of panel wipe (~$20)

6. Treat the window guide with lubricating chemicals
Reports of initial application being 100% effective
Easy to apply
Some concerns over toxicity regarding Teflon. Tefon is an effective lubricant as it is long lasting and considered a 'dry' lubricant (avoids the collection of residue) but, as stated by it's manufacturer, is toxic. While commonly used for a lot of application, it may not have been intended for use in places where it comes into contact with skin.
Longevity has been reported as long as 6 months
Other lubricants that are 'greasy' may not be desirable as they the window guide comes into contact with hands quite often, potentially causing more mess.
Cost USD$8-$50

7. Treat the showline with lubricating chemicals (same as 6)
Some have reported using ceramic coatings on the trimline. Ceramic coating do contain silicone, a chemical BMW considers unfriendly toward the material used to make the window guide, but whether it's in a form that is unfriendly to window guides isn't clear.
Whether due to general ignorance of how ceramic coatings use silicone, or actual issues with it, not commonly used to fix the problem
Use of sealants and waxes has been reported as effective but concerns about silicone seemed to have made these solutions rare
$10-$500+ (yes, you can buy $500+ wax)
Easy to apply with some reporting 6 months of silence.

8. Use of silicone removing cleaners has also worked well for some
USD$15

9. Paint shadowline trim
Paint could work but it may also fail. In one sense, it's cheap and it's easy. It's also dependant on your experience. Perhaps a shot of extra hard clear coat would work but would it be compatible with the black paint already there? Or, you could strive for paint perfection then have the same problem.

Note: Reports of effectiveness tend to leave out what season the solution was effective in. It appears Hot and Humid are the most challenging conditions while Dry and Cool tend to be less severe. It may be if you live in places like Florida, the North Eastern United States, Canada, the UK, non-mountainous area in Europe, you may have to use more expensive solutions such as guide replacement. In places like Texas, California, the middle east, etc, you may find cheaper solutions work well. Suggest anyone with this problem start with BMW's silicone removing cleaner. No joy? Try the tape/PPF solution either to the guide or the shadowtrim. If looking for perfection, all the time, regular guide replacement may be like getting new tires. A consumable item. As for trimline replacement, chrome is effective but it's by far the most expensive. I'd find an example on a car similar to yours to see if you like it as spending over a $1000 is a lot to discover you hate the look.

[casualDIYer]

Originally Posted by mysterio

Another shadowline trim creak victim here. My accidental mitigation strategy: chassis stiffening. I noticed that the creaking on my car was reduced after installing a strut tower bar and then further reduced with the addition of an F32 rear subframe brace. https://f30.bimmerpost.com/forums/sh...6&postcount=29

Thanks to OP for investigating!

Good to know. I am thinking of doing the subframe brace upgrade.

[crazyazz]

Most ceramic coatings contain silicon dioxide, Is this form damaging? Does anyone know?

[casualDIYer]

Another update.

For most the time the moleskin has been on, the doors have kept quiet. But recently, even in the dead of winter here (0 to -15C) the creaking has returned. It doesn't show up daily but seems to be occurring when the humidity is lowest. So it seems, again, the culprit is the shadowline trim. Looks like it's time to try PPF. I have to admit though, I had tried it once in the past summer and despite having experience with PPF, I found my first attempt to be quite a challenge and had to abandon the project. Maybe the next time will be successful. Updates to be posted within a month.

[casualDIYer]

Originally Posted by crazyazz

Most ceramic coatings contain silicon dioxide, Is this form damaging? Does anyone know?

It might be. Avoid if possible,