Davebrossi

So I've noticed with winter approaching fast here that what was once a rare sound has become a bit more common. Upon starting my S in the morning I'm getting a strange whirring noise. I'm of the mind that somehow the Starter Solenoid is acting up and keeping the starter motor on longer than need be. Has anyone ever had a problem with this? It's true I've done a lot of work on the engine, but I'm leaning towards the Starter system. I'll be monitoring the camshaft derivations via Durametric to make sure I haven't somehow bungled the IMS change I did several thousand miles ago. I should add that other than the noise the car is wonderful as always.

Dave H.

quite a few Boxsters do it. mine's done it once every 3 or 4 months for the last 4 years.

sjfehr

That's probably your secondary air injection pump and nothing to worry about. SAI is part of the emissions system and runs for about 30 seconds or so after startup (depends on temperature), injecting fresh air into the intentionally-rich exhaust to ensure full combustion until the cat and O2 sensors are up to temperature.

You can monitor SAI operations by the response of the O2 sensors if you're interested. If the sound stops and you instantly see O2 go from open-loop to closed-loop operation, that's your confirmation.

Davebrossi

Just got back to this. Thanks all! glad to know it's not one of those 'be very concerned, the pin has been pulled' noises :-) I'll put the Durametric on it during a cold start and see what happens.

Macster

Agree with this. Reports of the type of noise the OP reported in his post upon the onset of cold weather are common and it is almost always the secondary air injection pump running. Additionally in colder temps cars transmit noises better so while the pump was probably running in warmer weather the noise is louder, more pronounced and gets noticed.

amondc

The gear on the starter will make that noise. You can pull it and spray with wd40 or something similar. Doesn't seem to effect the performance of the starter.