This is driving me nuts, since it is sporadic:

I'll be driving along just fine, when suddenly a horrendous squeal/whine starts, and I can feel vibration in the floorboard.

If I tap the brakes, it quiets down for a second, then starts up again. If I tap the brakes a bunch of times, it will often go away completely, and then maybe not come back for a day, or maybe come back in 5 minutes.

I think it's one of the front brakes, but so far I can't quite trace where the sound is coming from. Of course, if I jack up the car and spin the wheels, no sign of any rubbing issues. Wheel bearings seem fine.

Any suggestions?

Thanks!!

Is one of the calipers loose? How about a broken spreader spring or brake pin?

The calipers "seem" fine. I took off both front wheels and didn't see anything of concern. And, as mentioned above, no sign of rubbing at that time.

(Of course, the car wasn't making any noise at that time... it is so sporadic that I can't check it out while it's making the noise..)

Maybe a spring is not always springing?

If you'd like, I can stop by sometime tomorrow evening and have a quick look see? Might help to have a second set of eyes.

Hey Ethan, that would be great! Plus, I get to see your nifty blue 914 again... that engine and exhaust sounds fantastic!

I'll PM you my address and phone number. Call first, since I might go out for dinner.

Thanks!

If it starts making the sound again, have somone walk along outside the car and help identify which corner of the car the sound is coming from. You can be easily fooled. I had a squeal that turned out to be a tiniy rock pinned against the rotor and the dust shield. It would go away when I hit the brakes. Sounds like something more in your case because you have the vibration.

^^^ I can't get it to make that sound at walking speeds. It generally happens any where from 30 to 60 mph.

I had Mike Mulligan's mechanic take a look too, last week. We went out for about a 5 mile drive, but of course, it didn't make that sound during the drive.

Last night, it was doing it pretty bad though.

OK, Ethan came over this evening and we drove about 10 miles, streets and freeway. Of course, not a squeak, squawk, or rumble.

He took off all four wheels and checked things out... no sign of rubbing or anything "funny."

Guess I'll have to wait until it's making this noise on a more consistent basis to diagnose.

Ethan, thank you VERY much for looking at the car... extremely appreciated!