GTI Backbox on a TDI

[GT_SPORT]

Hi Guys,

I have a 105 1.9 TDI and a couple of months ago  changed the exhaust back box for a GTI one. The main reason for the change was due to the twin exhaust pipes. The work was carried out by a exhaust centre and they used a sleeve in order to fit it to my existing mid pipe.

I have been driving the car for the past few months and the car drives fine, however since the day I got the backbox changed, the car makes a "woosh" noise. This tends to happen more when I engage the clutch and change gear. Also, after a long journey, if I leave the car on and walk towards the boot, the exhaust sounds as though it is "hissing".

I have took it to a few exhaust garages and they have assured me that I am not harming the car, however for peace of mind I would like to know if this is normal or have I got a dud backbox which needs repalcing.

[gazon69]

The whooshing is Nothing to worry about mate. It is the turbo you can hear as the gti exhaust will be less restrictive and larger diameter piping. As for the hissing, im not too sure about. Maybe there's a snake stuck up there? 

[GT_SPORT]

Lol @ a snake.

I was told it maybe the baffles that have gone in the backbox?

[Dave_TDI]

I have the same car with a gti exhaust, mine also made funny noises and i was told it was fine, 6 months later my turbo died, i now have a brand new turbo an it no longer makes the sound, sorry to scare you but get it checked out properly :)

[chrisr763]

Two people with a TDI and a GTI backbox  Does it sound good? Should i make the change?

[skard]

The reason I and others had a GTI backbox is down to GT170 boxes being so scarce and expensive in comparison. Either way it still needs adapting to fit the 140 bore.

[Trekmeister]

The transformation to the cars looks is astounding in my opinion

Sent from my GT-I9300 using Tapatalk 2

[GT_SPORT]

Thanks for the replies.

Indeed it does transform the back end and its true, 170 back boxes are very hard to come across as opposed to GTI ones.

Thanks for the head up Dave, at 90k miles my turbo is showing signs of wear but surely the hissing cannot be linked to the turbo?

When I had the standard 105 downward facing backbox I had no issues with noise or sounds from the backbox.

Prior to your turbo going, what signs did it give out? Loss of boost? Flatspots?

[skard]

Can you pinpoint it to the backbox 'hissing', or is it where the sleeve is? Could always be possible the sleeve needs nipped up (unless welded!).

[GT_SPORT]

Skard, it maybe the sleeve, it was fixed into place and and the exchaust place used exhaust paste, it maybe possible that the sleeve is loose at little.

[skard]

Try get underneath/look from the side and get someone to rev, you'll probably hear it better.

Sure mines did this once when the sleeve U clamp needed tightened. Could be that there is a slight gap where the cut is.