Noisy downpipe?

I've just had the downpipe and backbox replaced on my clipper and it now sounds terrible! 

I sent it back to the garage and had the backbox replaced under warranty but I'm sure it's the downpipe that's the issue. It's an almost hollow, blowing and metallic sound to it now, sounds pretty ok at low revs but over 2k revs it's unbearable!

Anyone else had this before?

The garage reckon it's because it's a cheap aftermarket exhaust so won't sound as good, but the last one was from Kwikfit (I know…) though.

I'm thinking last resort I might buy a different downpipe, I'm tempted to get a stainless manifold jobby but would prefer to do it on a budget as I think I'm going to have to (after 11 years) let the car go soon for something more practical anyway.

Any help or advice will be much appreciated! 

sounds liek it may be blowing, what kind of joint does it have the single downpipe with the 2 metal C clips, or double pipe with flange and 6 nuts

Get about 1m of garden hose and start the car, stick one end of the garden hose in your ear then move the other end around the joint on the exhaust pipe and exhaust manifold, I guess you have the C clips holding the exhaust downpipe on and the garage may of not replaced the O ring style gasket on the exhaust manifold and that's where it's blowing?
Try not to touch the hose on the exhaust pipe as it may melt!

Did the garage fit new C clamps?

O ring and C clamps so you know what I mean.
http://www.ebay.co.uk/itm/VW-GOLF-MK1-CABRIOLET-MK2-CADDY-SCIROCCO-EXHAUST-GASKET-CLAMP-161298115-A280-/221347468477?fits=Model%3AGolf&hash=item33895654bd:g:om4AAOxyA7tSZnGi

Also check you have no grommets missing in the engine bay on the bulk head or a split UJ rubber boot on the steering column as a lot of noise will come through the firewall into the cabin.   

Hey, thanks for the quick replies.

Yeah the garage fitted new C-clamps and replaced the gasket/donut thing. I can see they've dolloped a lot of heat paste around the join where the clamps are too, to be safe I guess.

I'm pretty the exhaust isn't blowing, I've covered the tail pipe and I couldn't see any leaks, there seems to be a lot more pressure than there was with the old exhaust too.

I'll have a look around the manifold as I wondered if it may have cracked or something when they changed the downpipe but it's not a 'blowing' sound though, it's more like a metallic echo, like there should be something to muffle the noise but its missing, or its a larger diameter pipe or something. …Its hard to describe as you can tell!

I can see why the garage thought it might be the backbox because it almost sounds like a dodgy big bore exhaust, but worse. Also I'm sure the noise comes from in front, not behind me.

I'll have a look at it over the weekend if the weathers good and report back. Any more advice or thoughts in the meantime will be much appreciated.

Just to update (and to get some more advice) I took it back to the garage who agreed that it wasn't the same as it was before but put it down to the exhaust note due to a different brand cheap exhaust. Hmm. They did however agree to swap the backbox, which made no difference whatsoever!

So I've been driving it for a few weeks and I thought it had quietened down until a mate got in the car and pointed out it was just as bad.

So now I'm thinking I might just swap the exhaust for another. Can anyone provide me with any advice on a brand to get? I don't want to spend megabucks, just something that is reliable and isn't going to make the car sound like a tractor!  

The above tests for a blowing exhaust aren't very good, the only way is to put your hand against it to feel leaking gases. I know its difficult to do when it gets hot, but I don't think you can 100% say its not blowing until you've done this. For example they might have caused a crack in the manifold during removing/fitting the new exhaust, that would need checking.

I'll go with hole in the exhaust somewhere.

Cheers Paul. I took it to another garage a few weeks back and they couldn't find any leaks. I've just had a look too and couldn't spot any either.

I have noticed though that the backbox really doesn't fit very well, so much so it's not actually attached to the back hanger! It's made by Klarius and reading on here, looks like loads of people say they're a rubbish fit.

If the backbox is that bad a fit, I'm wondering if the downpipe is coming away from the manifold under acceleration?

So I don't want a Klarius - are Bosal, Hoffman or Ernst any better? 

If its properly connected, the downpipe won't come away from the manifold under any conditions except when its being removed.

Have you checked for missing steering rack UJ joint boot and any missing grommets?

Have you tried some garden hose to listen for any blowing.

It not easy to try and feel with your hand for any exhaust leaks as the exhaust manifold will get very hot in a matter of minutes when the engine is running so be very careful.

The U-joint gaiter split about 8 years ago when Kwik Fit changed the original downpipe. I'm sure its because they forgot to fit (and then lost) the heat shield. Anyway, I wrapped it in aluminium tape and it's been fine ever since.

Couldn't spot any missing grommets… There aren't any blanks are there? All the ones I found had cables and hoses, etc

Haven't tried the hose pipe trick as I don't have a hose pipe lol. I need to get a oil leak sorted and tyres changed so I'll ask the garage to give the manifold a once over when I take it in.

When I changed my UJ boot as it was split for about 4 years I was really surprised how much noise was stopped with a new boot.
 There is also a big rubber bung which lives inside the car at the bottom of the steering column and sits on the shaft of the UJ which also helps stop the noise travelling into the car.

I thought I should update just in case anyone ever has the same problem in the future.

I ended up buying a replacement Bosal downpipe and backbox from Amazon of all places. Really quite cheap too - £80 for the backbox and £30 for the downpipe. Well worth checking in future for random parts, I just searched for the manufacturer part numbers on Google and they popped up.

It's worth mentioning the quality and fit difference between Klarius and Bosal too. The Bosal backbox just slotted straight in like you imagine a genuine part would. I had to check a few times I'd not missed anything as I was sure it shouldn't fit that easily!

Anyway, all sorted now. I fitted the new backbox first - small improvement. I then had the downpipe swapped (including new fitting kit) by a garage and it's back to normal now. Well pleased to say the least!  Thanks for everyones help and advice.

Good to hear the feedback on the exhaust and glad you are happy with it now, I bought a NOS exhaust for my Mk1 scirocco the other year and that was make by Bosal.
You can see the VW logo and lable on my back box.