Weird buzzing noise at start up

[ScottyP45]

Any one got or had this? When first started in the cold, and on fast-idle, theres a raspy buzzing sound from the upper rear of the engine cover area, then it dies away as the revs drop to normal, its maybe a buzzing fuel injector i'm thinking but its barely audible once a minute has elapsed after cold start.

doesnt increase in pitch when revved, just in volume terms, while its idling high.

 

[shagga]

Yeah I do but heard it on two other's also.

 

[ScottyP45]

hmmmm - I wonder if theres a 5th injector for fast idle?

Its annoying cos its loud at first and want to head it off before it becomes a real fault.

 

[PW-Motorsport]

Sounds like the secondary air system, the air pumps can be noticable on cold start.

Similar thread running in the A3 section.

 

[ScottyP45]

No mate I dont think its the SAI cos i always hear that for a few seconds even before this buzzing started out of the blue. It sounds like an injector and is at the right rear of the head, the SAI is under the drivers wing, well away from where this new noise is coming from.

 

[Steve B]

Hi

Any news on this fault, I have the same kind of noise that lasts for about 30 seconds then goes, not sure wnat damage it could be doing.
Car runs well, with not faults but this is starting to get to me.
I feel there could be a trip to Audi coming on soon if I don't get to the bottom of this!!!!!!

any advise would be good?

Thanks.

 

[ScottyP45]

No further forward on this noise mate, but my battery died tonight, see the thread I just posted. Dont think its related, but might just be. The car made some freaky weird noises inside form the dash this time when it wouldnt even turn over...


I did originally think the noise was coming from the alternator, could be something buzzing as a dying battery sucks the life out of the system trying to replace the current taken form starting.

 

[g60jet]

it could be your abs pump.

 

[ScottyP45]

its not as far right as the abs pump, and there are no codes or lights, just a steady buzz for about the first minute of cold start running, then never again until next morning etc

 

[james@approvedfabricators]

It was an oil pick up problems..............sludge yeh!? Not enough oil getting to the top of the engine, I think the noise comes from a unit at the back of the cyl head but dont know its name.

Cheers

 

[ScottyP45]

no its not that. my oil pressure is perfect, level good and oil clean.

The noise is louder now than ever, is coming from the alternator area or behind it.

It sounds like a bit of plastic rubbing on a spinning bicycle wheel spokes - like you used to get from those things that were free in cereal...

Its LOUD and not coming from the auxiliary air pump or the abs pump, as I listen over each of those the noise is from the middle of the engine where the intake runners are.

It goes quiet when the revs drop from fast idle, is louder when revved but doesnt "speed up" with the revs, just gets louder...

 

[pjmspeedy]

Sounds to me that your brushes are gone in your alternator!

 

[ScottyP45]

doesnt get faster with rpms......

the alternator does.

 

[ScottyP45]

A wee update - I have done a phone vid and put it on youtube, could you guys listen to it and see if its the camshaft adjuster or the SAI pump, or what? Sorry for the dark picture but it was 7.45am to catch it stone cold. The sound is quiet on the vid too so turn up yer speakers lol (btw - it does not get faster if you rev the engine, just louder. And you can hear it die away in pitch and volume when the engine drops to idle from fast idle - then after 5 minutes its completely gone)

http://uk.youtube.com/watch?v=Ur5v0Va0kmI

Enjoy!

 

[NHN]

Its the secondary air pump system fella, its only present 1st thing in morning usually or on 1st start up of the day & only lasts for upto a few minutes or so, its much more noticeable in the winter trust me, the 8L S3 had it, the B6 S4 I had also had it, dont worry yourself as it isnt a problem, if it gets louder then could be sign of water damage as my S3 was from a split pipe, but tbh my S4 was noisy & wasnt faulty at all.

 

[ScottyP45]

ah cheers matey thats a relief!

I wonder if removing the fuse to the pump and living with the cel will be a good idea?

 

[NHN]

Uh no, as its only once a day for a few minutes surely you're not that anal fella, lol

 

[ScottyP45]

hehe - I am the pickiest person you will ever meet mate

I've changed cars because of the exhaust note, or the cornering, or because some plastic bits kept coming off of the interior....

The wife despairs - i've had the audi 8 months and i want to replace it because the gearbox is notchy and its too harsh over rough surfaces.

 

[aragorn]

that sounds very rattley to me, but obviously its hard to tell from the camera video as often it can make noises sound better/worse than they actually are.

What i'd do is pull the fuse or unplug the SAI pump and see if the noise stays. i would imagine that it should be possible to disconnect/remove the SAI and fool the management system into thinking its still there. I fitted a vauxhall X20XEV into a nova for my brother and it originally had SAI. As long as the SAI relay was connected to the ECU the engine management light stayed off, regardless of wether the SAI pump was on the other side of the relay or not...

 

[ScottyP45]

cheers aragorn, that was what I was thinking. I heard the fuse is in the ECU box, is that under the plastic scuttle panel?

I will pull it tomorrow, theres a chance that the "incorrect flow detected" dtc might appear if it uses an air-switch to tell if its running, but someone on another (yank) forum where they deleted the sai on purpose said the dtc stops coming up after a restart...

 

[J7USS]

Gosh! You need to have a word with Next door about their Harvester Evil,Couldnt even hear yours running - lol!!

Can see where you coming from now, that would annoy me for the rest of the day every morning I started it up.

 

[ScottyP45]

lol @ j7uss - it nips my tits. Every morning its zzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzz


It annoys the feck outa me. It is the SAI, its loud under the drivers wheelarch.

im buying a merc coupe next, the 320 cl or the cl500 c-class if the wife lest me get a 5 Litre motor #