[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,

[casualDIYer]

The quest goes on to kill off the squeak.
The dreaded sound all M, X, and 3 series sedan owners with shadowline trim experience over time with their cars.

Holding on for a week now, even in 29C weather: Xpel PPF Ultimate (it works but not as easy as you'd think to apply)

My first attempt was at the start of May 2025 but there were so many bubbles and stretch marks, even with a heat gun, I had to rip it all off and start again.

On May 11, another attempt was made with Xpel this time with far fewer bubbles than the first try. It still needs more perfecting but it seems to be working. The car is dead silent.

1. Wrap the PPF up from inside the car toward the roof
2. Do it in 2 steps. Note where the shadow line breaks mid rear door. That's the first piece of PPF. The next piece of PPF must be cut from a rectangle, not a long strip. There is too much tension attempting to do it as a strip.

Let's see how the rest of the summer goes but right now, PPF is looking good.

Here are three views. As you can see, bubbles are a problem. Not sure the best way to get rid of them

[Jvac]

Originally Posted by casualDIYer

The quest goes on to kill off the squeak.
The dreaded sound all M, X, and 3 series sedan owners with shadowline trim experience over time with their cars.

Holding on for a week now, even in 29C weather: Xpel PPF Ultimate (it works but not as easy as you'd think to apply)

My first attempt was at the start of May 2025 but there were so many bubbles and stretch marks, even with a heat gun, I had to rip it all off and start again.

On May 11, another attempt was made with Xpel this time with far fewer bubbles than the first try. It still needs more perfecting but it seems to be working. The car is dead silent.

1. Wrap the PPF up from inside the car toward the roof
2. Do it in 2 steps. Note where the shadow line breaks mid rear door. That's the first piece of PPF. The next piece of PPF must be cut from a rectangle, not a long strip. There is too much tension attempting to do it as a strip.

Let's see how the rest of the summer goes but right now, PPF is looking good.

Here are three views. As you can see, bubbles are a problem. Not sure the best way to get rid of them

Attachment 3741141
Attachment 3741142
Attachment 3741143

You sir, are committed. It's admirable. My car just recently developed the creaking of all 4 window guides after ~10 years. It's pretty annoying and it's exactly like all the other descriptions (shadowline trim, uneven roadway, warmer temps etc).
It's disappointing to see no lasting fix. I sure do appreciate the time and effort you've put in to share your experiences but it seems to be a bottomless pit trying to solve this issue.

[schernov]

The only lasting fix is Teflon tape carefully applied to the shadow line trim per TSB. And keep the door seals clean and hydrated with Gummypfledge.

[fe7565]

Looks like this has been a problem through several model lines. Seems to be caused by friction between the shadow line trim and the seals. Applying an anti-friction agent in certain areas seems to resolve it (depending what anti-friction agent was used) or had varied results.

https://www.e90post.com/forums/showp...1&postcount=13

https://www.e46fanatics.com/threads/...s-pics.709202/

[Igorwhitef20]

Is there a more easy way for fixing this or you must apply hundred of different glues and hope it will be fixed?
No one still found the universal fix?
I have this noise on my rear right door and i just volume up music loud enough so i dont hear it annoying me.

[casualDIYer]

Originally Posted by Jvac

You sir, are committed. It's admirable. My car just recently developed the creaking of all 4 window guides after ~10 years. It's pretty annoying and it's exactly like all the other descriptions (shadowline trim, uneven roadway, warmer temps etc).
It's disappointing to see no lasting fix. I sure do appreciate the time and effort you've put in to share your experiences but it seems to be a bottomless pit trying to solve this issue.

Go with PPF. Any shop can install it or you can do it yourself. The shadowline is in 2 parts. From the front of the car to just past the b-pillar. You can use a 50mm wide strip of ppf, apply it from the top of the shadowline, wrapping inward. For the next section though, you'll need to cut a large square of ppf and cut out the shape. A strip of ppf won't work as that will cause too much tension in the film.There is a vinyl kit out of a company call slickmod.com. Same idea but that kit is vinyl.

[casualDIYer]

Originally Posted by schernov

The only lasting fix is Teflon tape carefully applied to the shadow line trim per TSB. And keep the door seals clean and hydrated with Gummypfledge.

Actually, that's not true. The teflon tape also fails over time because the teflon itself rubs off the tape and the tape needs to be re-applied. I know people who have used the teflon tape and needed it re-applied more than once.

[sling44]

My 328i has got the door seal noise too. And it's a prime candidate: Shadow line trim, older car, in a tropical climate. I've read this thread a while ago and have kept coming back to it whenever the noise annoyed the hell out of me again. Which has been frequently. And now, finally, I've done something about it.

I bought two different tapes off Amazon Germany (available elsewhere too, I'm sure), as I wasn't sure which one would work better. One was a teflon tape. It was described as reducing friction in drawers. But it turned out to be whitish, not clear, and with a kind of fabric backing. That's not what I wanted. The other tape was described as nano tape - whatever that's supposed to mean. It's a clear tape, and at first glance similar to acrylic tape, but neither quite as stretchable nor as sticky. Nano tape apparently is most common in a double-sided version, but I had ordered the single-sided one. And that's what you want. Search for "clear nano tape single sided" on Amazon.

As casualDIYer suggested, I stuck it to the underside of the shadow line trim above the door. I started all the way at the front, near the fender, and went back to just before the sharp downward curve of the trim above the rear wheel arch. The tape was not flexible enough to go around that curve without throwing creases that I didn't want, so I ended it there. My tape is 3 cm (1.18") wide and therefore wider than the shadowline trim. So after I stuck the tape as far inward as possible, to where the trim meets the car body, I went back to the front and slowly smoothed the overhanging tape upwards, getting rid of as many creases and bubbles as I could. My tape is described as "reusable" and "removable with a trace", and I could in fact easily peel a stretch of it back off when it didn't sit properly, and then reposition it. With the doors closed, if you look closely, you can see the edge of the tape now, but it's thin and clear (like PPF, really), so not obvious at all. If you can find a thinner tape, maybe 2 cm wide, that would be even better.

It's early days, but for now the noise seems to be gone. I have to go up a pretty steep incline from an underground garage, and when I go up at an angle (so as to not scrape the front splitter), the car flexes as usual but the doors now stay quiet. Same over speed bumps. CasualDIYer said that the teflon on teflon tape will rub off over time, but I could imagine that this won't be the case with the nano tape. It doesn't seem to be coated as such. Potential long-term issues may be that it turns yellowish with age (as PPF often does too), or that the edges lift off and won't stick anymore, but I'll have to see about that. Will report back here how it goes, also if the noise does come back eventually - as it seems to do with so many other "solutions" too.

[casualDIYer]

Sounds like another good solution. I am waiting for my vinyl chrome delete kit to arrive to see if that works. Fingers crossed. So far, after a year or so, PPF has worked well. I did the driver's side of the car, and it is mostly silent. The passenger side creaks like an old boat. I will try the vinyl and see if that helps.