strange popping sound (like clapping hands) in cabin- 99 S70

mshinrockford · Post by **mshinrockford** » 05 Dec 2007, 20:27

Ok, so I was driving down the road the other day in my S70 with my daughter and her friend in the backseat when I heard my daughter clap her hands very loudly right behind me. I asked her, "Why did you do that?" She said, "Why did I do what?" I said, "Why did you clap your hands behind my head?" She said "I didn't." She also heard the noise and wondered what caused the sound. About 5 minutes later the same thing happened. Very loud. Very non-mechanical. Any ideas? Since it was quite cold outside (below freezing) my only guess is that the metal body panels were popping due to contractions from the extreme cold. Does this theory make any sense? In all my years of driving in the cold Michigan winters, I've never heard anything like this with any other car. The car had no other symptoms (i.e it drove and operated perfectly). Any ideas?

Post by **MadeInJapan** » 05 Dec 2007, 20:47

Hard to say....I would just keep an eye (or an ear in your situation) on it.

tripleb · Post by **tripleb** » 05 Dec 2007, 20:57

I have heard body panels popping from bad spot welds or cracks and I can see how cold weather can make the metal contract more than usual and make the noise occur.

These can be pretty difficult to isolate and repair. Ideally you want to be able to recreate the noise so you can take it to a shop, or body shop.

B

bobsnow100 · Post by **bobsnow100** » 06 Dec 2007, 14:19

Maybe something like a plastic bag or other road debris got stuck on something under the car.

Post by **MadeInJapan** » 06 Dec 2007, 15:22

Question:
1. Does it only happen when your daughter is in the car?

2. Has it happened since?

I tend to agree that it may have been something caught under the car, especially if the sound hasn't returned. If it has, take a look under your car with a strong flash light.

mshinrockford · Post by **mshinrockford** » 06 Dec 2007, 16:31

Thanks for your suggestions. I really don't think that it was coming from under the car since the sound seemed to originate from within the cabin area. If you clap your hands loudly that's exactly what it sounded like (no dragging, clanking, or stratching...just a short, loud pop). My latest thought is that it could have been the glass in one of the windows popping. Since the weather wasn't that cold, I can't imagine the cold air making the glass crack, but it was such a sudden sound that I'm starting to wonder if there was something going on with the glass. I'll inspect the glass later tonight to be sure that there are no cracks.

bobsnow100 · Post by **bobsnow100** » 07 Dec 2007, 13:10

Do you have a sunroof? Maybe the wind is picking it up and making it pop like you're talking about

mshinrockford · Post by **mshinrockford** » 07 Dec 2007, 21:22

Yes, I do have a sunroof. Thanks very much for your good idea. I don't that it's the sunroof since the noise was so sudden and just a very quick clap or pop. The noise was literally as quick as a clap...no noise before or after the pop. Just "pop!"....then nothing! It did happen 3 times during a 30 minute drive, so there was roughly 10 minutes of silence between the pops. The best was to describe the sound would be to image a large piece of glass experiencing an internal stress-induced crack. The weird thing is that I haven't been able to find any cracked glass. That's why I'm thinking that it may have just been a metal body panel "popping" due to the cold. I'm surprised that no one else has ever experienced this???

icelandic · Post by **icelandic** » 08 Dec 2007, 05:26

Take a good look at the rubber strip on top of the front glass. This strip has a t shaped profile and the vertical part of the t goes between the glass and the body. It sometimes breaks near the center and at certain speeds, due to air flow it starts vibrating creating a loud clapping noise such as the one you describe.

Good luck

Icelandic