Noisy/blowing Exhaust - No Holes

[dunc 0]

I got a 1.9gti (8v) about a month ago and the exhaust started blowing and had been gradually getting worse. So got round to checking it out yesterday, jacked the car up and started it. Then proceeded to examine the exhaust to see which bit I'll have to replace, couldn't find any holes/blows though.

 

Can only assume that one of the boxes has packed in, does this sound right?

 

I don't know where in the exhaust though and don't particularly want to replace the whole system. Not sure what make it is but it doesn't look to old, is this common or is there something else I'm missing?

 

Thanks in advance for any assistance,

 

Dunc.

[j_turnell 137 3 Cars]

Have you checked the exhaust manifold for cracks as this is a common problem?

[dunc 0]

I gave it a quick check but might have missed it as was expecting something obvious like gaskets in that area not cracks. Will look again, cheers for that

 

Dunc.

[johny105_y2k 1]

i've found when the baffles have gone in a box that if you give it a tap with a hammer you can hear the stuff rattling about in there.

[lagonda 42]

Are you sure it's actually blowing?! My car has always sounded as if the exhaust is blowing, when it isn't, so have other CTi/GTis I've driven.

[dunc 0]

Assumed it was, sounds like an exhaust with a hole in it - the noise is coming out the back of the exhaust. Engine runs like a dream but exhaust noise is rank.

 

John, I know that trick but it's not a rattling buzzy sound like loose baffles.

 

I'll take another look tomorrow, manifold seems ok though, where is the usual place for them to go?

 

Thanks for the pointers

 

Dunc.

[allye 530 3 Cars]

They can rot inside-out, so sounds like one of the boxes is bu**ered!

[omega 82]

but your hand over the end of the exhaust and you will hear if its blowing

[Rupertfinch 6]

It's bound to be a Bosal exhaust - noisey friggers. The increase in noise is psychological, you largely ignore it at first but then it starts playing on your mind, more and more the droning continues until you can't take it anymore...

 

Sorry I'm on my third Lemsip.

[McDude 33]

When my manifold cracked it was underneath and very hard to spot. In fact I only noticed the crack when I removed it to fit a new dipstick tube.

 

Didn't sound especially noisy though, so I'd probably rule that out.

[dunc 0]

but your hand over the end of the exhaust and you will hear if its blowing

Yeah tried this and there's no holes so must be the internals.

 

Thanks for the advice everyone

 

Dunc.

[james_ix 0]

It's bound to be a Bosal exhaust - noisey friggers. The increase in noise is psychological, you largely ignore it at first but then it starts playing on your mind, more and more the droning continues until you can't take it anymore...

 

Sorry I'm on my third Lemsip.

 

I would agree with this statement following damaging the exhaust on my 205 Gti rally car on an event, so badly that it all needed replacing. A standard manifold, standard down pipe, brand new bosal centre box and brand new ashley rear box got fitted to the car.

 

Every part was installed correctly with new gaskets and mounting rubbers, but the centre box always sounded like it was blowing!! So the car got jacked up and everything checked, checked and checked again. No holes, no cracks just concluded that those BOSAL centre boxes are noisey and sound like they are blowing when they are not!!!

 

Check if it is a Bosal box by looking for their name embossed on the can section. If your still not happy, change it

[dunc 0]

Will check when I get a chance to get under the car, thanks.

 

Dunc.

[paulsupervts84 0]

my 205 done this and i found out it was a cracked manifold, i checked it and now it is spot on

[gav_mi16 0]

If a cheapo downpipe has been fitted, (without the centre split), this tends to create more noise, and if it has the split it may have come apart at the top, restricting the flow and creating noise.

 

Currently the girlfriends std 205 blows through the down pipe bracket (the bit that clamps to the manifold). It's supposed to be continuously welded all round, but its not

 

took me ages to work that out, i thought the manifold had cracked again, it is damn noisy.