C5 RS6 can hear a rattle at 1200revs??

[Voooom]

Hello guys, hope everyone is well.

I have a question that hope you guys can shed some light on:)

Recently took the RS6 to my local garage after a persistent rattle at roughly 1200revs for a split second, similar to the sound of loose vibrating undertray, previously the garage said it was just something loose, nothing to worry about. This time I told them to take it up on the ramp and have another look, now diagnosed as coming from the engine??? Mentioned something but I haven't got a clue what he meant.

Its very hard to notice it but I just don't know what it could be.

Any input would be much appreciated.

[audi_driver79]

Your always going to worry about something but if you can't remember what the garage said better double check. Last time I heard a strange noise I had a cracked sprocket as you all know, could be anything. Hope you get it sorted.

[Voooom]

Cheers for your response.

The mechanic said its something you can't do anything about, unless you change the engine otherwise it'll run fine like this but it'll just have the tiny split second rattle. But it's only got 78k surely the engine can't be needing replacing at such low mileage???

It's very smooth to drive and gears are nice and smooth also.

In the process of trying to sell it as well and obviously now that I know this, its my responsibility to tell any potential buyers even though the mechanic said don't mention it as its nothing obvious and the car will run fine. But any interested party will run a mile after being told this.

[SuprSi]

Its the variable valve timing, mine does exactly the same at ~1100-1200 rpm, just for a split second like you said.

I got flamed last time I suggested it, but I bet they all do it if you actually listened out for it and raised the revs slowly. It's not something you'd notice with normal driving.

[Voooom]

Does it sound similar to a loose undertray? Performance is not affected its just that sound.

I'm in the process of selling so unsure as to what to say to a potential buyer, unless its something common on the C5 Audi RS6s?

[SuprSi]

I'll see if I can get a recording of it when I get home for you

[Voooom]

Cheers mate, that would be brilliant:)

And is it something to worry about? Will it have an impact on my asking price? At the moment my 2004 RS6 C5 Avant 78k is on for sale £9499 and on here for £9199.

Again any input much appreciated.

[Voooom]

SuperSi did you manage to make a video recording of the noise?

Might swing it round to Audi when I get a chance.

Iv had enquiries about the RS6 but as soon as I mention there is a slight vibration for a split second, the buyer is put off straight away. So a bit stuck at the moment especially as I don't know whether this noise is even serious as no performance is affected, is barely noticeable and wether it is somthing common within the Audo C5 RS6

[SuprSi]

Hi, sorry I forgot to do this yesterday. Here's the link to a short sound clip, it's in the noisy industrial estate at work so I blipped it a few times. It's a pretty quiet noise, definitely the variable valve timing in my opinion as the revs hesitate when it gets to 1200 and makes the crunch noise, more throttle is needed to get past that point.

https://clyp.it/ycxq0ibh

[Voooom]

Cheers for that mate and Yes that's the noise.
How long has yours been there?
Is it something serious?

[SuprSi]

No worries. It's done it since I bought the car at ~134k, it's done 151k miles now and the noise hasn't changed or got louder. I think it's just a normal noise to be honest.

[Voooom]

I'll still have to mention it to any potential buyers.

Iv dropped the price on it to £8899.

[SuprSi]

Why would you have to mention and discount for a normal engine sound? That doesn't make any sense.

[Voooom]

True. My concern was due to me being unsure.

Thanks for clearing that up and all your input.

[Voooom]

My engine management light has also come on!
Code read along the lines of: Engine Bank 1 too rich and another code for Bank 2

Any ideas, lambda sensors? MAF sensor?