b6 S4 Shutter on cold startup
 

Hey everyone,

2 weeks ago I bought a used 2004 S4 with around 69thou kms on it. Beautiful condition, Audi certified, all the major wear parts (clutch, tires, brakes, rotors) replaced and the full Audi inspection was done. I went through the vehicle with a fine tooth comb before I bought it and it was immaculate. So my vehicle paranoia kicked in the other day when I started it for the first time in the morning after it sat in my parking garage for the night.
Upon cranking the engine, for the first 10 or so revolutions there seems to be a metal on metal "shudder or clanking" sound that happens right when the engine fires up but immediately goes away. It will not happen again unless the car is left for over 12 hours in the cold parking garage. I can even fire it up, and shut it down immediately and i can not duplicate the noise.
From my basic mechanical knowledge I can tell everyone that its not the starter, and the sound sounds more like taking a piece of sheet metal and tapping it against another metal object. It makes no other noise throughout the entire rev band, just that initial "cold startup" noise.
So i scoured the internet and found only 1 site that made mention of the phenomenon..... v8esfo.com
The author addresses this noise as a "subtle nuance" of the 4.2 engine, and that is literally the only resource I can find on the matter. I contacted Audi care and they had no bulletins or recalls to tell me about but (of course) suggested I take it to the dealer.

My problem with the dealer is... if I take it to them, they will need to park it inside or somewhere cool for the entire night, and when they start it in the morning, they will only get 1 shot at identifying the noise, because even if they shut it down and try again, the thing wont make the noise. So that means I give up the car for 2 days and they tell me nothing is wrong! haha lame...

My question to all you 4.2 owners out there (especially the B6 2004 people) is HAS ANYONE EVER HAD THIS HAPPEN TO THEM? Should I stop being paranoid and chill? If this has happened to you, had you gotten any answers at all? Any repair advice? Any damage this may be from or (worse) may be causing?

Thanks in advance for any ideas guys, Ill post a picture of my baby to show you how pretty she is, even in stock form...

J

Re: b6 S4 Shutter on cold startup (Answered)
 

So I got an answer to this question. Its no big deal for anyone else who may be curious about this.. below is the Audi tech bulletin..

Re: b6 S4 Shutter on cold startup
 

Some Audi engines are louder than others regarding cold startup valvetrain clatter. Even tho the TSB listed the 2.7T, I don't hear any valvetrain noises at startup, yet the 3.0 is famous for valvetrain clatter on startup and it is quite noticeable, to the point of asking the same questions you did about your 4.2

BTW, nice S4 Avant!