pinging/rattling sound at 3100rpm

[boxster1]

03 Boxster S is getting a sound that I would describe as rattling or maybe pinging coming from the engine at almost exactly 3100rpm. +/- 100 rpm and it runs perfectly smoothly. This has been happening for more than a month now. It is fairly loud. Any ideas what this could be?

[Kurt W]

Mine does that exactly as you describe. I think I recall something about vario-cam action at that speed. I do know that mine has made this sound since the day I got it and no ill effects.

[Lobo1186]

i get some chatter at startup sounding similar to what you describe and im not sure the car gets quite up to 3k when i start her but... idk hopefull someone shed some light for ya

[clickman]

Engine size?

[Lobo1186]

well i ahve a 2001 2.7 and teh OP im guessing has 3.2 since its a 03 S

[boxster1]

yes, it's a 3.2

[blue2000s]

It's most likely to be the engine mount.

[clickman]

I would have said motor mount too, but for that it's described as pinging/rattling, when I thought motor mount created vibration. I've got the 2.7 and occasionally, not always, get the seat-of-the-pants vibration at around 3100-3200. I'm at 50k miles, so in theory I'm due for the motor mount.

[blue2000s]

Originally Posted by clickman

I would have said motor mount too, but for that it's described as pinging/rattling, when I thought motor mount created vibration. I've got the 2.7 and occasionally, not always, get the seat-of-the-pants vibration at around 3100-3200. I'm at 50k miles, so in theory I'm due for the motor mount.

Symptoms depend on how worn the mount is.

[boxster1]

I don't feel any vibration. I only hear the sound and it is fairly loud.

[Daniel R]

Could be a number of things. My 2000 S has exhaust resonance at the same rpm, but then I am running no cats and 2" pipe from the after-market headers to the muffler so it is to be expected.

The first thing I would look at is the exhaust. Maybe a part of it is touching the body of the car??

I would not think it is an engine mount, I replaced mine last week and am familiar with symptoms, but I could be wrong.

Good luck with your diagnostics.

[sd_boxster]

3000ish RPM is where our exhaust hits resonant frequency. If you have a loose heat shield or a catalytic converter that is starting to degrade, that's the RPM where you'll hear it rattling/pinging.

If you post up a sound clip, you might get some better guesses. Good luck!

[dm1270]

Originally Posted by sd_boxster

3000ish RPM is where our exhaust hits resonant frequency. If you have a loose heat shield or a catalytic converter that is starting to degrade, that's the RPM where you'll hear it rattling/pinging.

If you post up a sound clip, you might get some better guesses. Good luck!

I have a 2001 boxster with 100,000 miles on it. I hear a rattling from the catalytic converter, I know, because I used a stethoscope to detect where the sound was coming from. Might be an oxygen sensor cap.

[Matt Fredrikson]

Might sound odd but I had a similar problem and it turned out to be the steel clip the sandwiches on the center of the under body paneling. Didn't have a nut on it so it was just rattling around in there right at 3000 rpm as well, worth taking a look! Just reach under the car with a flashlight or whatever and wack the under panneling and you'll know right away.

[speedyellow]

Took it to the dealership numerous times , mechanics on both LA Auto Gallery and Pacific Porsche told me it's nothing to worry about, it's just the fuel injectors. 5 yrs later no problem so far.

[Bobiam]

If the car has more than 50-60K on it and you plan on having it next year, you might as well do the engine mount now. First there is a good chance that some minor vibration is causing an exhaust rattle. The 3000rpm area is exactly where the problem is most often noticed. And if that wasn't it, you will likely need one by next year anyway. It should be part of the maint schedule at 60K.