S3 ticking/tapping/sticking at low revs?

[aterro]

i went to fit my new diverter valve today but before i did, i heard this noise.

Recently around 1/2k revs, it would sometimes get stuck, e.g. sticking revs at 1.5k and then go to normal idle.

The above never really bothered me as its only very occasionally.


Then today: the noise when i rev lightly upto 1.5k, it taps a few time then stops, if i rev more than 2k, no tapping at all.

Seems like to to be a ticking more than tapping, like ticking injectors? or something moving in and out ?


You can hear it in this video, a lot more towards the end of the video, so please try and watch the ending more than beginning.

Any ideas what this is?


Its an S3 8P!

http://vid182.photobucket.com/albums/x75/aaront1234/IMG_7599_zps42b98low.mp4

 

[S3 AEX]

Are the revs fluctuating on their own have you noticed?

 

[aterro]

When idling? Nope

It's only when driving and coming to a stop it gets caught sometimes.

Seems to be stable though

 

[S3 AEX]

Try a throttle body alignment via vcds mate first.

 

[aterro]

Haven't got vcds! Damn.

Would this be ok to buy
Item number on eBay.

131547889603

 

[aterro]

It's only doing the ticking noise when warm.

It sounds like a relay ticking but obviously it's not

 

[aterro]

Any ideas?

 

[aterro]

Anyone

 

[MarkpS3]

These engines will make a ticking noise, as you mentioned, it's the injectors. But that sounds a little louder than normal to me. Ever changed the HPFP or cam follower? Timing chain been replaced?

As for the RPM sticking....probably some faulty sensor so would need to scan for errors...

 

[aterro]

Never changed HPFP, cam follower was changed 2k ago? Could it be cam follower that makes a ticking noise if worn?

Scanned with vcds

No errors.

 

[MarkpS3]

I wouldn't think so on its own, I was more going in the direction of it contributing to a lack of fuel pressure.

Is this ticking there permanently when the car is idling or if you maintain an RPM, or just briefly during the 'blip' ? If you do mean the latter then I'm really not too sure if I can hear the noise you mean mate.

My local VAG specialist offered a diagnostic check on my S3 for £45. They had it in for around an hour or so and checked various things as I was concerned about a bit of extra engine noise. Perhaps worth looking in to, small price to pay for that peace of mind.

 

[aterro]

It doesn't tick at idle.

Only between 1k and 2k revs when raising revs with throttle

Could it be a sensor?

I may change can follower just in case. Looks quite easy.