magicgreg

I went out yesterday afternoon with my dad's mate who has a Carrera S for a spirited drive around some country roads, I was out for around an hour and a half and whilst out gave it a bit of right foot but nothing silly, I'd probably say I didn't go past 6K revs.

On the way back, taking things nice and easy, I noticed that the dump valve sounded a bit louder than usual, also when the turbo was spooling up it also seemed slightly louder.

Now today during normal driving the same is happening, the drive and power seem to be the same as is everything else, just the sort of building up humming/whoosing noise from the turbo is slightly louder and the same from the dump valve. Also when revving the car at a standstill maybe upto 3K revs, the engine doesn't sound as healthy, not too technical I know but I'm crap with these kind of things.

Is this anything to worry about or is it due to something such as colder weather conditions.

The dump valve and turbo are as standard BTW.

I haven't given the accelerator some jip today just incase it was something so I can't really say whether power was down.

Any ideas that may put my mind at rest or do the opposite are welcomed.

My Scoob is an 07 STi with 3500 on the clock.

Cheers

G

ethanrob

iTrader: (3)

take it to your local dealer for a diag check buddy,tell them its running funny,covered under warranty,so any issues will go through there till,also will give yourself peace oif mind

marcus

magicgreg

Aye, thats what I was thinking.

Although do you think they will kick up a fuss about a catback exhaust system??

G

bob r

iTrader: (46)

Take it to the dealers anyway, and if they won't look at the car because of the exhaust, take the exhaust off and try again at another dealer.

You could always swap the backbox before taking it which is quick and easy.

It does sound like a loose turbo hose or similar.

Mikkel

I would put it back to standard before taking it to the dealer mate, then if any work does need doing there will be no issues with warranty cover. Better safe than sorry.

marmski

I agree with putting the old exhaust back before taking it to the dealer.

I wouldnt worry too much about the dump valve sound, as this is normal. Mine did the same around 2k miles... i couldnt hear it at all until 2k then suddenly i could hear the dump valve and the turbo sounded stronger. (Dealer said it was normal and the car was running perfect)

I would be quite worried about the rough running though. Try sticking the standard centre pipe back in and see what it does, because im assuming you have a straight through centre pipe now fitted? (where as the stnd has a cat in it i believe... or certainly a resonator at least). Some newage imprezas boost spike when their centre pipe has been changed without a remap... some dont. Its kinda like luck of the draw.

Whatever you do... dont take the car back to the dealer with that exhaust on, because its almost a license to tell you its your fault!

magicgreg

I'd be surprised if it had anything to do with the exhaust as the backbox and centre pipe have been on my car for a month and a half now and there have been no issues.

I'm going to take the car out today and have a good listen and drive and see if it was just me noticing something different and being worried about it more than I should.

As I said the car seemed to be running as per usual, the only thing was the turbo and dump valve sounding slightly louder than usual, if however this is normal once you have put a few miles on the clock then all is good.

I shall report back today with anything that I find.

Thanks for all responses thus far.

G

marmski

I would be suprised if it was too.... but lots of people here have reported boost spikes with a changed centre pipe on a newage... where as others seem fine. I was only suggesting a possible reason for poor running.

If its literally just the dump valve u can hear now, then its perfectly normal... get it to a dealer to get it checked if ur worried.

mgcvk

It sounds like it may just be something you are imagining to be honest, particularly if everything seems fine with the car and you have no CEL. In my experience dealers aren't too concerned about exhausts particularly if they pop the hood and see everything is standard and as it should be - no induction kits etc. Clearly if you had suffered some kind of engine failure and wanted it repaired under warranty then going back to standard exhaust would be necessary. I have had CEL codes checked at the dealers (when still under warranty) with full decat and had no issues.

v8voodoo

Funny thing this, I noticed that my engine noises changed around 3-4000 miles. Dumpvalve noise became apparent and I was convinced I could hear the turbo spooling...? This was also after a spirited drive....

Maybe they do some sort of loosening up thing...?

Odd.

magicgreg

Firstly thanks for all of the replies!!

Just been out for a drive and found the following things:

The engine noise seems slightly different, more of a 'whirling' noise when revving at a standstill.

The car seems to be more free revving on the move and the dump valve is louder when changing at lower revs.

The car now idles at under 1K revs, more like 600-700K and is more quiet after the car has warmed up.

I am sure the car is still running ok, the power seems to be the same and I have had no lights flash up on the dash. I was sure at one point that it didn't feel as powerful when planting the a accelerator but I think it might just be in my mind.

When I say that this noise was louder or that noise was quieter, I am talking minimal changes but you just notice them when you drive your car everyday.

Could just be the car loosening up and changes happening or it could be something entirely different........

G

bushiwarrior

i would'nt worry bout the exhaust i would worry more about takin the dump valve off tbh they may not even look at it with it on.

magicgreg

Dump Valve is standard mate.

G

bushiwarrior

kool

Beastie

iTrader: (2)

You know it has an adaptive map? It adjusts to your driving style and can change from economy to power. I believe the light whipping you gave it has switched the mapping to the more agressive map and that is what you are feeling.
After my wife has been ***** footing about in my MY06 i have to drive it like i stole it to get it back to full beans.

magicgreg

That could be it then!

It does seem slightly more free revving.

It was just the difference in various levels of noise from different components that I didn't really understand but it seems a few people on here have experienced similar changes, plus I am nearly at the 4K mile mark so it maybe easing up slightly. Hopefully this is it anyway.

I am just going to keep a close eye on it for the next day or two and then make a decision.

Thanks again

G

Mikkel

Another option if you are still worried in a few days is to take it to Alyn at AS to run a quick diagnostic on it. He obviously won't be bothered about any after market parts and his prices are usually reasonable.

A different scenario, but my car sounds different after my remap (especially the turbo and dump valve) but it is running fine, so may very well be the map.

magicgreg

Yeah, I think it could be related.

At the moment the car is running as per usual (I think) and there have been no warnings via dash lights or in the drive or performance.

I'm going to see how things go and then if there are developments then I'll take it in either to a specialist, dealer or both.

Thanks again to all.

G

magicgreg

Just a quick update on my STi:

Gave it a good wash today and noticed something, the backbox seems to be hanging slightly lower than it was before, again its a minimal change but before I couldn't really get any fingers between the lower part of the bumper and the backbox but now I can.

Could this be affecting the engine and dump valve noise?

Also upon hard acceleration the engine noise now seems to over power the exhaust noise, there is a definite change in the engine noise, the build up of the turbo is pretty loud on hard acceleration. Performance wise it still seems the same.

Any ideas?

gallois

well first things first, get the exhaust checked as you said it looks as though it has moved and you are now hearing the turbo and dump valve a lot more, it is possible that perhaps you have backed into something and caught the exhaust and damaged a join on one of the sections.

magicgreg

Exhaust hasn't been touched so its weird that it has moved.

Going to get it checked tomorrow though to see what the score is.

G