Saw like Sound on Cold Start Up. Any Ideas

Hi Everyone, I have started to notice an electric saw like sound when I start the car in the morning from cold. Sounds like this clip I found on YouTube http://www.youtube.com/watch?v=0KaEMCm4FMQ The sound only happens when the car has been left standing for a few hours and then goes away after 40 seconds Approx. Its starting to get louder and i wanted to know if anyone else had encountered this. Doing some quick research, I found that some people think it could be the air pump. Do i need to replace this? If so how much does it cost? Any thoughts, suggestions or ideas would be welcome. Thanks

Get down to your Indie immediately !! An experienced ear will tell you straight away what it is ............. I am just hoping it is nothing to do with engine internals!

Thanks Paul. By the time I have driven there the sound would have gone. Gonna book it in. The car drives perfectly, its just that initial noise.

It does sound like it might be the auxillary air pump. This runs for between 50 and 179 seconds, depending on the temperature. You could try disconnecting the pump when it is cold, or your indy could rig up a 12v supply to it so can run it in the workshop. Edit: Porsche price for the air injection pump is £1022 inc VAT.

Hi Richard, Good to hear from you and thanks for your diagnosis. Is it serious? ie can i continue to drive. or should I take it in straight away as Paul suggested. Does the pump need replacing? I have noticed the sound for a week or so now but as mentioned, it is not affecting any other aspect of the car. Was planning to get it all checked out when I book it in for a service next month.

It isn't going to get any better by itself, so I would get it sorted as soon as poss. Edit: If it was me, I would disconnect it until you can get it sorted. You may get a CEL, but I wouldn't worry about that.

Okay, Thanks. Any idea on what sort of cost I am looking at?

Sorry - my edits cross with your posts! Price is as above. Like I say, try disconnecting it.

WOW!!!!!!!!!!!!!!!!!!!!!!!! Thanks Richard Better start saving up

Bosch OEM equivalent available for fraction of price. I could only find this US site for them but must be available here from somewhere. Or just import. http://www.autoatlanta.com/results.php?partnumber2=996%20605%20104%2000

Hi Geoff, Seems like a bargain. Just need a UK supplier. Just phoned Porsche Apart and they have one for £120 (with 30 day warranty). Its a back up option. Looking at Rennlist etc it would appear that is not an uncommon problem. Some people have fixed it by giving it a good clean. My pump seems to be working however I do not know to what capacity so do need to get it sorted. I am sure the boys at Jaz will be able to help. Just out of interest is there anyone else who has had this problem????

You could also try Type911, EuroCarparts, or Design911 for the Bosch equivalent.

Richard could you kindly confirm the part number please? I have found 996 605 104 00 and the bosch equivalent is 0 580 000 022 Type 911 and design 911 are going to get back to me. I think this is the part http://www.ebay.co.uk/itm/Porsche-996-Engine-Air-Pump-996-605-104-00-/281074673031?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item41715b2587

Yes, that's the correct Porsche number. I can't say about the Bosch number, I'm afraid.

Just an update for you. Phoned Northway and they can get the part from Bosch in Germany for £541 + VAT. Huge saving so thanks Geoff for the suggestion. Richard, can you tell me where I can find the pump as I want to disconnect it myself and see if it the real problem here. The most gutting thing about this is that the job to replace is only 30 mins (if that is the problem)

You can see the pump here, and there is a plug/socket to disconnect it:

OMG!!!, I think I may just have to have a go at this. Richard, prepare yourself. I am going to have a go at disconnecting the plug and start the car. That way I will know if its air pump thats gone. Gonna have your mobile number set to speed dial just in case (Joke!!!) Thanks

Just wanted to say a massive thanks to Cotswold Porsche Specialists especially Lyndsey, who provided some great service in locating the part for me as well. Thanks

Think you might want to try this before laying out £££££ to Porsche. http://forums.rennlist.com/rennforums/996-forum/737900-removed-sai-bearings-w-pic.html DIY http://forums.rennlist.com/rennforums/996-forum/735878-sai-repair-diy.html You might have to register but I think it will be worthwhile.

Hi Richard, Just had a look at this, and is something to try. I have been told that possibly a good clean out with compressed air may help as well. Thank you so much for finding this. I asked before, but no response..... Has anyone experienced this sound before????,

I'm pretty sure you could remove it and still pass an emissions test anyway. Another load of EU Bull if I'm not mistaken. ???

Just an update everyone, I removed the old one this weekend and it was pretty easy. Removed the air duct, three 10mm bolts for the bracket, disconnected power. Removed the old unit from the bracket put the new one in and put everything back as before. No more sound!! I just hope its working!!! [8|] No CEL as well! I just wanted to thank everyone for their help!!

Well done Tiku! Good result! And the start of a DIY career, no doubt.......

Tiku. Can you do a quick service for me? It's due next month