low whine on cold start

[hucqym]

I have this low whine on cold start on my 2001 boxster (115K miles) that seem to last about a minute or so and then stops. It sometimes changes pitch a few times while I do nothing but sit idle. Doesnt change with clutch/gas-pedal press/release or vehicle moving/stationary. I have checked the drivebelt, waterpump and other pulleys but none seem to indicate any wobbliness! Any clues?

I wish there was a glossary of porsche sounds/noise somewhere so I could be more apt :) ...but I guess whine/screech would be close fit.

I do have signs of a clutch on its way out. That is new and most likely completely unrelated. Just wanted to throw it out there anyway.

[RFM]

The noise at cold start is probably caused by the secondary air pump, the pump is always a little audible when running in cold start conditions, even when new. From here i can not hear how much noise the pump really produces, but if the noise increases, i would certainly have it checked.

[grover]

The secondary air injection pump is part of the emissions system, and will always run when you first start the car, and will continue to run until the catalytic converters and O2 sensors are up to operating temperature. It's located on the top-front-right of the engine, right in front of the AOS. When you say "low whine", is it consistant with a fan you just weren't expecting to hear, or does it sound like it's failing?

The good news is that if it fails, it's not going to impact the driveability of your car at all. The bad news is that it'll throw a CEL you won't be able to get rid out without fixing it.

Edited August 4, 2012 by grover

[hucqym]

yup a pump that I wasnt expecting to hear would pretty much fit the bill. (...not just because thats a happy situation I was hoping for! ;))

..and then throwing CEL isnt really bad news now, is it? Its that which doesnt throw a CEL that one needs to be wary of! :)

Thanks RFM and grover!