why dose my s3 sound so pants (need to sort it or its going)

[harvey01]

hi all ive got a 3 inch down pipe with a decat and it sound poo almost like it rattles from cold as the air rushes down the flexi. Its also got a jr induction kit witch dose add power but it may as well not be there sound wise . And to top it all off there is a rattle sound as i change gear and it pulses as low rpm ! im trying to stick with the s3 but its not making it easy HELP

 

[Benjiman46]

Sounds like your DP is touching your subframe mate... Is your car an APY? Secondary Aid Injection makes it noisy on startup too... Remove it if you have an APY cos you don't need it with a decat (or even with a cat for that matter...)

 

[harvey01]

it an amk and ive looked around the down pipe and its got room around it . the rattle has been there from the day i got it happens on start up im thinking its a camchain prob but dont no how to check it . im going to put a sports cat in the exhaust to take the tinny sound out but it sound pant from cold

 

[coatesy]

have you checked all the heat shielding on the exhaust. i had this cause a right noise.

you would know if the DP was hitting the subframe, when i got my custom one fitted it sounded like my car had vtec when getting in to the higher revs because it was touching so much.

 

[harvey01]

no it not the downpipe how do i check oil pressure and the camchain and would it make it pusle at low rpm

 

[coatesy]

when you say a pulse what do you need a hunting idle or pipes rubbing slightly ?

oil pressure the only thing i know of is buy a oil pressure gauge.

and cam chain the only thing i could say is maybe take the rocker cover off and see if the chain is tight

 

[harvey01]

it is hunting at idle and i think i will take the cover of and have a look . how hard is it to change the camchain tenchener

 

[coatesy]

if its hunting at idle maybe you've got a vacuum leak or your maf is on it way out, have you scanned the car with vagcom?

to change the cam chain tensioner i think you will have to take the cams out, im sure some body will back this up, as when i changed mine it was when i was rebuilding the engine so the cams where already out.

 

[harvey01]

hi mate thanks for your help id like to have it vagcomed but i dont no anyone local to me other than audi im in brighton

 

[Greg-S3]

The cam chain tensioner wouldn't make it hunt at idle, does the car drive well through the rev range? Is it just lumpy at idle? If so it would be worth smoke testing the car. We have a smoke tester at work and it can pick up the smallest of air leaks! I'd personally start with the basics, check for air leaks, check the boost pipes, check the vac pipes, brake servo pipe, perhaps spray some brake cleaner on the inlet manifold (if the revs pick up the manifold gasket is leaking) check the exhaust manifold doesn't have a slight crack in it, I think that's all your problem will be! If you want to smoke test the car, most good garages have one, we charge half an hours labour to smoke test and that will show air/boost leaks so it's money we'll spent!

 

[harvey01]

ok mate ill look in to it

 

[<tuffty/>]

We smoke test most 20v's that come in with running issues these days as its all too common for them to leak... pipes under the inlet manifold being prime candidates...

They look like this on an AMK/BAM... APY is a bit different but the principle same applies... PCV pipes and vacuum pipes rot and split... there are plenty of threads here with details of how to sort and look in the stickies too...

Its not just the OEM stuff either... see a lot of 'custom' builds that have issues too


<tuffty/>

 

[harvey01]

hi all so i went to santa pod today and ive notice that my rattle is easy to her outside the car . it happens when started from cold and when you chainge gear just as you come back on the power im thinking it must be my cam chain but is it worth changing the gides first or getting the hole thing and if how much as i thik it needs to be done ??????????????????????????????????????/

 

[harvey01]

help

 

[Greg-S3]

It's hard to say without hearing it mate, any chance of a video inc the sound to maybe help narrow it down? Ive heard cars with chain rattles down to a water pump rattling, heat shield on the cats, could be so many things mate it could be.

 

[harvey01]

ill try but its only when its cold or hot ive looked for heat sheild but its not that

 

[Greg-S3]

Is it just for split second from cold? Or does it rattle all the time? May sound silly but is it a mapped car? If so what fuel are you running it on? Only asking as the acceleration noise may be pinking? Like I said mate its hard without hearing it. Maybe buy a cheap stethoscope and get someone to start it from cold while listening the the cam chain, may help either confirm or rule it out, they are always handy to keep anyway for listening to wheel bearings etc!

 

[harvey01]

it sound like a heat sheild noise but ive looked at all that and the car is running a standerd map

 

[Greg-S3]

And it sounds like its coming from the chain area or just the bay in general? Have you looked underneath? When was the oil last changed? It may be worth taking the sump off, check the oil pick up pipe isn't blocked, just in case it's oil pressure related and upon first start and under load it's taking a second or so longer to get the oil picked up! They do suffer from blocked oil pick up pipes

 

[harvey01]

thats what i was thinking but i did it before i went to the pod ! it dose sound like its coming from the top right and my car is an amk engine so a new one is £350+ thats why i wont to no if i could try the gides first as there £30 ish but i dont no where to find them .

 

[Greg-S3]

You don't know where the guide is, or where to get the bits from? So you've had the sump off already and cleaned the oil pick up? How many miles has your car done?

 

[s3gazz]

i would of said downpipe too but if u say its the top of the engine god nose get it scanned well werth it

 

[Greg-S3]

Have you checked the oil pressure?

 

[harvey01]

not yet how can i do it ?