Hi Guys, new owner here 2003 996 Carrera 4S. There is a strange whining sound on start-up sounds like a jet engine. Sounds like it's in the driver seat with you. However it's not as loud when you're at the engine and it quietens down after a few seconds. I bought it from a repair shop selling it for the owner. The mechanic said it was vacuum pump and they all make this noise. I'm not so sure. Is he right?

 

SAI pump - secondary air injection. Lights off at cold start, runs about 60 seconds and turns off. May come back on again, like if you hit a stop light. It pumps air into the exhaust system to fire up the cats (catalytic converters). It's an emission thing. Located left side of engine bay.

 

Thanks for that noise is a bit concerning to a newbie

 

Its not a catastrophic part that you have to worry about. But it can make quite a bit of noise. There are a couple of threads here on RL on OEM parts suppliers. Was a $300 part. Dont know what it is today. Mine makes alot of noise on the cold months and nothing in the summer. Keep forgetting to replace it.

 

It's $937 and 2.45x that if you want the Porsche brand product. Better off looking for salvage.
Porsche Secondary Air Injection Pump Vemo V45-63-0005 V45 63 0005 V45.63.0005 996.605.104.04 V45630005 996-605-104-04 996 605 104 04 4046001706530 99660510404 | Pelican Parts

 

Guys thanks for that, your cars are amazing your aftermarket is fantastic. I have nothing but a sun damaged interior!

 

Holy crap!

 

It amazing what Porsche wants $$$ wise for a stupid SAI Pump.....I left mine laying in the garage floor last time I had it off ....

Yeah I know I will have that code every time i run the codes....ppfftttttt !!!

 

Hi Guys, I have discovered that it is not the SAI unplugged the SAI the noise remained. I have tried to attach a link to a video you can hear a strange whistling sound any help identify and it would be great thank you.

 

Take a look at your steering fluid level.

 

Since you said the sound is in the driver's seat with you, have you made sure the noise isn't coming out of the speakers (door and dash). I know it is a long shot, but that sounds a lot like electronic interference buzz in stereo system that has a wiring problem. Easy to diagnose though.

 

Electrical engineer here. I agree with yvvvz. Since you are recording the noise in the cockpit, it matches the RPM and is very likely RF interference in the sound system. You can put your ear next to the door speaker and listen. Not sure how to eliminate it if that's what it is.

 

Yep sounds like a ground loop noise!
Turn off your stereo, or remove fuse to test.

 

Hi Guys, so I found it hard to believe that it could be from the stereo. However, I pulled a speaker out stretched it as far as I could on its loom, put my ear to it and you're absolutely right it's coming from the speakers.
I tried it with the radio, obviously very very faintly and the sound goes away so my question now is without driving around with the radio on permanently. How do I fix this?
I apologise profusely for my previous scepticism, any help whatsoever will be gratefully received.

 

Most commonly alternator 'whine' heard in stereo is caused by a bad ground to head unit. Try and repair ground wire to stereo or replace ground with heavy wire