Expanding foam squeaking?

[birdie2000]

I used expanding foam to seal up my IB wall, and also fill a couple relatively small voids to seal my trunk from my cabin as best as possible. I now have a lot of squeaking coming from that general area of my car, although it's not always there. I'm pretty sure this is what is causing it, it just sounds like that's what it is. I noticed it very infrequently after I first installed everything this summer, but it has seemed to have gotten worse since then. I have no idea if it's because of the cold or if it's just a factor of time.

So, has anyone else had this experience? Any thoughts as to what can cure this, or what to use next time to prevent this?

[drtool]

Cold, more squeaking, check. Strut tower in the trunk might be a good cure. Or part of one.

[Chad]

if it does not adhere it will squeak.

[pionkej]

What kind of expanding foam did you use? Great stuff?

[BowDown]

Isn't that ironic. Go from rattles to squeaks. Not sure which I hate more.

[birdie2000]

Yes, great stuff. I wasn't using it to cure rattles or anything, just to seal off the trunk from the cabin for an IB setup. As far as adherence, that makes sense, but at the same time the stuff doesn't seem to want to adhere all that well. I think that it pretty much adhered in the beginning, but through either chassis flex or the expanding/contracting of metal from the weather it has become detached. Unfortunately it's hard to look for though because a vast majority of it has been carpeted over.

[ErinH]

I know exactly what you're talking about. Though, I can't hear it in the install per se, I do hear it when I'm removing excess or the like.

[birdie2000]

Yeah, I don't hear it because of the system playing, but when the car is hitting bumps, turning, or braking. Basically anything that causes the chassis to twist/flex in some way. There's nothing I'm really willing to do right now because I'm looking to get rid of the car soon. Aside from this issue I'd like to try an IB setup again in my next car, and I don't want to have the same problem again. This might be enough to keep me from doing it again though.

[ErinH]

if you find that you hear the squeaks, I'd venture to guess that the wall needs to be addressed. I can't tell you what Xmm of displacement in the foam causes XdB (the point at which it's audible). However, I would suspect that you have a good bit of movement in the foam, and that makes me think there's likely too much movement in the surrounding areas, thus compressing the foam enough for it to be audible.
IOW, I'm wondering if you can't just address the wall, make it much more rigid so that there is no movement on it, and thus no audible creaks/squeaks from the foam because it's not being compressed near as much.

just a thought...

[birdie2000]

I did use it to seal some gaps up in the corners where the rear deck/quarters/rear windshield all meet too. I'm guessing that's where most of the noise is coming from. Today driving around, I heard nothing, which is the case for 75% of the days I drive it. I could stiffen up the wall too, it's currently only one sheet of 3/4" mdf holding two of the eD buyout 12's (EHQS12). I didn't think I needed much more since those are relatively wimpy 12's. The wall is pretty rigidly bolted to the vehicle though, and fits rather tight between the strut towers on its own. Could theoretically be the wood rubbing against the metal in that area too now that I think of it.