Sounds like something is just caught in there.
 

2000miles into my 3500 mile roadtrip, I fire up the car after stopping for dinner. Belt starts a very mild squeek, increases with revs but VERY minimal. Put the car into first, I hear a "flap........ flap......... flap........." noise as I roll down the street. Coming from behind the passengers, somewhere behind us we can hear this. It kind of sounds like it is coming from the passenger side wheel well, cannot pinpoint while driving. So I move up the revs and shift into second "flap... flap" noise still emanating sounds like every few rotations of a wheel or something a light "flap." noise. Increasing as the car speed does.

I put a little movement into the throttle, and then this happens all within a 1 second time span:
1) the motor torques up ~500 rpms
2) but no power to the wheels,
3) then all the power to the wheels and the rear tires even squeek like I just hard dropped it into gear.
4) Flap noise is gone. Belt squeek is gone.

I cruise around for 5 days and 1500 more miles, no problems, no noises, seemingly perfect 2.7L.

My passenger said "sounds like something just got caught in there... and it worked itself out." I agree that is what it sounded like but I joked and said what in where? Pieces of palms trees don't just get "caught" in the motor. Or maybe it did?

Anyone have any idea WTF happened? I have a shot in the dark theory but want to hear some experts' opinions first.

I have had little stones get caught in my rear disc brakes a couple of times.

second time i figured it out immediately so i stopped, backed up 5 feet and hurrah the noise was gone when i resumed going forward.

my e-brake line rubbed against the wheel and it sounded just like that, though i didn't have the rpm weirdness...

vid link

Is it like an intermittent hamster wheel squeal? Mine was much to my shock a loose spark plug. I'm not the only one who had this in fact someone sent me a sound file you might find in a site search. The sound file was dead on for my noise, two loose plugs found.

Have you looked under the car to see if anything is wrapped around your driveaxles or if there is any sign that something was like a torn boot or areas of the axle that are cleaner than others? What kind of condition are your cv joints in? I have a CV that is going out and it will make a noise for a few days and then nothing for hundreds of miles then noise again.

not to hi-jack this thread
 

but the strangest noise I've ever experienced was a week ago. Car had been sitting in the garage for a few weeks with e-brake on. I started it, put it in rev. (6 spd man.) released e-brake, let clutch out and heard a very gut-wrenching loud "clank"!! I put the clutch back in, put it in first and rolled it fwd a little then back in rev. and back a little. Noise never came back again. What the heck was that?? Was it the e-brake stuck on then disengaging? It was a terrible metallic clanking noise. The car just turned 40k and has been meticulously maintained it's entire life. Anyone experience this??

sean

Davemon,

You said you stopped to get a bite to eat, returned and heard the Flop, flop, flop driving away? Sounds like you had a cat under your car and once you accelerated it decided to "depart the fix". :p

Your water pump is right behind the passenger seat.

Can you tell if anything was stuck in the wheel well?
Are all your CV Axle bolts tight?

Give me a shout when you get back in town if you want Danny
to give it a once over?

mike

Was it moist/damp during storage or was it raining the last time you drove it and parked? The parking brake was likely glued onto the rotor by rust. I've had that happen on other cars I've had but not onbthe boxster.

It was actually very dry. I do suspect the p-brake though. I don't use it very often and had it pulled up to raise the top the last time I drove it. You're sticking p-brake theory is a good one. That's kind of what it felt like.

sean