[PinkyandPunky]

Hello everybody.

I own a 2009 1.4 petrol 5dr i30 that has developed a fault. The exhaust sounds very loud when I start up the car and can be heard within the cabin. The loud noise vanishes when the car has been driven for a few miles.

A few other symptoms of the problem are that upon start up, the car idles above 1000rpm but eventually drops down to below 1000 when the engine has 'warmed up'. There is also a tiny tiny rattling coming from underneath the car when driving, although most people can't hear this as it is such a small noise (I have very sensitive hearing).

Any help would be appreciated.

[josh1990]

Often as metal heats up and expands, leaks are sealed thus eliminating the noise. I would lay under on a cold start and check the flanges along the exhaust pipe. May just need a few $ or £ gasket replaced. The slight rattle may also be the same issue, and the flange just needs nipping up.

[CraigB]

I’ll put my dibs in for worn catalytic converter