Sounded like I had a flat, but I didn't
 

My and a co-worker were cruising back from lunch when a sound appeared. At first it sounded like I was going to slow in a high gear and the engine was getting bogged down, but the tach was up around 2k, so I knew that wasn't it. It really sounded like maybe a flat tire. The sound seemed to change with vehicle speed too. We turned down a residential street and parked under a tree, prepared to change a tire, but all 4 were fine. After looking around, checking tire surfaces, wiggling wheels that might have come loose, etc we decided to drive and see if we could figure out which corner it was coming from. The noise was gone!

Along with the noise, you could feel it in the car. The passenger felt it too.

Totally gone now, no idea what it was.

Theories on what the heck that could've been?

Only thing I can think is something was stuck on a tire and fell off when we stopped.

Maybe there was water in the fuel from somewhere that was causing a backfire, but you burned it all out.

maybe you picked up a stick?

Maybe it was unintended non-acceleration?! OH NOES!

There was a chunk of stick near the car when I got out to look at it. About 8 inches long and not quite an inch thick. It seemed louder than a stick would be though.

Brett

In my Civic, when it rains, water causes the exhaust to touch the bottom of the car and the cooling makes it expand then contract. It's pretty loud and at first thought it was an ABS malfunction or flat tire. This noise also changes with RPMs.

Was it raining?

If not, then I don't know what it was, maybe something just got stuck in the wheel well.

My first thought was that you may have got a rock somehow thrown between the caliper and the wheel; however, when that has happened to me (twice in my life now) it sounds HORRIBLE with screeching as if the wheel were going to blow off.

Describe the sound in more detail.

Sounds like bad gas to me.

I've had a few sticks stuck to the underbody of my car before (live on a dirt road) and it does sound a lot like a flat tire. It's louder than you think it would be because it resonates through the shell of the car. It's definitely the kind of thing that makes you pull over right away and take care of it. That's my guess, especially with the car being so low to the ground it wouldn't take much to pick something up.

I'm pretty sure he knows what bad gas sounds like.

Ripping fabric.

:clap:

And we just had a thread yesterday where folks were saying spare tires are too much weight.

Imagine if this had been a flat tire. He could have just parked it and waited for a flatbed? That's no fun!

Isn't think it was gas, though I did just eat Chipotle. I put the cluth in when I heard it, and the noise slowed down with the car, while the engine maintained a constant idle speed. The fact that you could feel it in the car pretty well was the most troubling.

I really hope it was just a stick!

It was dry, sunny, about 70F today. Going about 30-35 MPH on a paved road when it happened.

Brett

My spare will be in the trunk, on the car, or on the paddock during autocross. I don't need reduced weight for going to the grocery store it to buy dog food :)

Brett