220volt

2008 Boxster S 987.1 23k miles on it.

I recorded sound example. I rolled down the window and extended my arm down to the drivers door while driving on the parking lot. It sounds almost like a rusty mattress or even breaks squeaking.
https://drive.google.com/file/d/0B58...ew?usp=sharing

- Noise shows up only when car warms up. After 10-15 minute ride. Could not hear it while cold. And it is intermittent when warmed up. More present than not, but comes and goes.
- I can hear the noise louder when I roll down windows. It seems to be coming from left side of the car. Not sure if it's front or back. Did not test right side of the car.
- Gas pedal or breaking have no effect on the noise. Noise is there regardless what those pedals are doing.
- Turning the wheel while driving does seem to effect noise somewhat, nothing drastic though.
- No noise while stationary at the light, or when I turn steering while stationary.
- No noise while I rock the car up and down while stationary - if suspension is suspect, shouldn't I hear that noise while doing this?
- I put some WD-40 on strut and boot to all four wheels about 3 days ago, but it seems that it actually gotten worse.

Any ideas are appreciated.

Thanks

LexVan

I can't get the audio clip to play.

My guess would be water pump.

How do you know what a rusty mattress sounds like?

220volt

Try it now. I converted it to an MP3. When you press play wait for few seconds it should start.

Don't ask

LexVan

Still not working on the app with iPhone.

Archimedes

Take it to dealer and if they can't easily tell what it is, they can use a magic ear to pinpoint it.

220volt

So I checked steering pump pulley and it is not lose, it is pretty tight.
I pushed on front fenders and there is no noise.
If push comes to shove, I'll just take it to indy shop on Monday.

badabing

Does speed change the noise?

Engine rpm?

Road speed?

220volt

It does not. Also, throttle and break pedal have no effect on the noise.

kiesan

Next time it happens, try engaging the parking brake very gently and see if that makes the sound change/go away. Could just be the left side parking brake shoes still barely making contact inside the parking brake drum even when the e-brake is off.

220volt

So someone suggested to check bread dust aluminum shields and I did. I bent break shields outwards little bit, since it was warped and was little too close to rotors, and dusted it off with some canned air, and so far no noise, for three days already. Now, the weather has been very warm for the past few days, so not sure if that has to do anything with it, but we'll see when it gets colder if squeakiness returns. So far so good. Thanks!

220volt

It looks like with the colder weather the noise is back. You think it is a good idea to take off all 4 wheels and start lubing everything with some silicone rubber safe grease?

LexVan

No but it would be a good idea if you started telling us about your preventive maintenance and are you on schedule?

For example, when was the serpentine belt change? When was the water pump changed?

220volt

Car only has 23k miles. I got it 2,000 miles ago, but nonetheless I am religious regarding maintenance, so already change motor oil, gear oil, break pads, break flush, checked all three belts, check steering fluid/pulleys. I wanted to start from 0 since I did not know habits of the previous owner.

LexVan

Your serpentine belt should've been replaced in 2014. Has it been done?

I still think your noise is related to the serpentine belt a pulley or the water pump.

220volt

Hmm interesting. I just I called Indy shop that replaced my break pads, and they said to bring it in so instead of messing with it more, I'll bring it in tomorrow and hopefully will be able to replicate it. I'll mention the serpentine belt. Thanks