B Chester

I have a 2003 Boxster S with 17,500 miles. Lately, on a cold start, it emits a metallic engine whine that lasts for several minutes until the engine is warm, then the noise disappears.

Any thoughts on what this might be?

Macster

My first thought is you are hearing the secondary air injection pump running which it does upon a cold start and sometimes for a minute (or more) when the air temp is cool to cold.

But it is impossible for me to say with any certainity this is what you are hearing and that it is normal.

My experience with my Porsches and other cars is the pump sounds like a hoover vac running in the distance. I can hear the noise but it has no real characteristic, metallic for instance.

The noise could the pump but the pump is going bad.

You really need to have someone with some experience give a listen and advise you.

Sincerely,

Macster.

logray

Post a recording on you tube!

B Chester

you tube video as suggested

Lightning MO

Yes, that sounds like the air injector pump, and the bearings are starting to whine. To be sure, remove the engine cover and verify that the sound is coming from the air pump on the passenger side of the engine compartment, circled in the picture:





You may or may not be able to service this pump (maybe clean it out and lubricate the bearing surfaces), otherwise if the bearings are hammered and there is alot of shaft play it will eventually need to be replaced (but you can still drive the car). Others may have more experience messing with it...

- Lightning

http://www.youtube.com/lightningmo

logray

+1 to above post, and it doesn't sound all that abnormal to me, but maybe that is just the other sounds making it difficult to hear.

Macster

Agree, after listening a couple of times to the clip. My hearing's not the best so I'm always a bit worried about what I hear being what everyone else hears but I heard nothing disturbing.

The secondary air injection system is a sophisticated system, critical to emissions reduction, and the DME is quick to identify any problems in this area. If the check engine light is not on unless a tech deems the noise scary my WAG is there's nothing abnormal about the noise.

But the OP should have a qualified tech give a listen just to get an expert's opinion.

Sincerely,

Macster