SET

It is like clockwork. At exactly 2,200-2,300 & 3,200-3,300 & 4,100-4200 RPM there is a metal on metal sound . Increasing and decreasing RPM has the same result. Does anyone have an idea of what could be causing this?

pl

i feel i have the same problem.
i can feed the metal2metal vibration on the streeing wheel.
my car is 996 MY2001 3.4 tip, 50KMile. last oil change was last year spring.....

SET

i can't feel it, just hear it - and it does NOT sound good.

Benjamin Choi

Hmmm might be slight knocking (click noise) especially at lower RPMs which I understand is normal operation

wdonovan

If you're lucky, some junk rattling inside a cat. If you're not, a resonant timing chain vibration?

BruceP

That's where I'd look first. I had a scary noise in mine when I first got it, turned out to be a broken baffle in one of the mufflers. Don't panic yet.

redridge

let us know your findings please... TIA

pl

my car also makes a big metal to metal noise when starting up, if it sits for a few days.
could be the timing chain.....

99firehawk

why are you reving the car in neutral, what are you hoping to acomplish.

timing chain vibration engine knocking......where do you guys come up with this stuff

1999Porsche911

Are you drinking again Brad? No one said anything about reving the car in neutral.

grant911

Just to enjoy the lovely symphony of a flat six would be my guess.

J.Seven

Any update?

J.Seven