When you first start the car, you cant hear a thing even after 5min of normal driving. When however the boost kicks in after 10min of driving then I get this loud rattling noise coming from the downpipe of the exhaust. I have taken the car to a garage and was told by the sound of it that I would need a new downpipe as the cat has gone on it.

Can anyone confirm if this is true or if it is a gasket problem ?

SC008Y

 

Sounds more like heat shield is heating up and vibrating probably one of the spot welds gone , when cold it contracts and is tight fit heats and expands and is loose , heat shields are also on the headers could be these ?

Mark

 

I have got it checked and it is not the heatshield, it seems to be the cat inside the downpipe. Replacing the downpipe should do the trick I hope.

 

You're chance to get a de-cat or sport cat downpipe? Unless you're talking warranty here, I would'nt fit a OE item!
JohnD

 

Sounds like the cells in the cat has come loose

time for a decat

if its not under warranty ofcourse

 

The downpipe on my car is a decat (from the looks of it) so how can there be a noise coming from the cat inside it? Is there some sort of filter still inside it?

Since the noise started, the petrol has been sucking too much aswell

What could be the problem here ?

 

Hi this is my first time here as i've only had my scooby 6 weeks, and what a 6 weeks they have been. Don't know why i never got one of these cars sooner.

Just i have one problem- when starting from cold there is a rattle, it's dead tinny. Iv'e had a look all over and can't find anything. Someone please help me before i take everything apart..

 

You should first learn to start your own thread mate

 

Does it make the noise when idle?
Try revving it parked up and dip the clutch at the same time, does the noise stop?

Mine used to make a rattling noise just as the turbo was coming in so initially the garage thought the turbo bearings were gone or the insides of the Cat were loose.

After dipping the clutch we realised it was the clutch release bearing and the noise was transmitted up through the gear box. It sounded bloody awful.

New clutch kit fitted and end of noise for the last 10k

 

The noise is still there even when being parked up, I had the car lifted up and think it is really coming from the exhaust downpipe. But I have a decat and was told the noise is coming from the cat

 

i have the same problem. when parked up. when you rev it then come off the gas..as the engines loses rpm..it sounds like a load of marbels are going threw the downpipe / exaust. could this be the cat?

 

so were in the same boat then, I was told by a mechanic that its the cels that have come loose in the cat in the downpipe. But how can this be if the downpipe is a decat from the looks of it