Hi all. I have had a 2003 Octavia VRS estate since Feb and am very happy with it apart from one annoying thing. When its started from cold it is extremely noisey for about the firsr 2 mins every time. The revs are up at about 1200 rpm and I am getting a noise almost like the exhaust is blowing inside the engine bay. Then it warms up, the rev go down to about 8-900 rpm and the noise goes and it ticks over quite nicely. Any ideas??

Secondary Air pump.

Do a search, but basically it pumps air into the cat for 1-2 minutes on cold starts to improve cat efficiency.

The rivets holding it together fail, making the pump housing split apart and leak.

It can be taken out and repaired with small bolts.

Mine was failing when I removed it:

How to remove:

http://www.pimpmyskoda.co.uk/V2Images/ModsEngine/AirSystemRemoval.htm

Look here. http://uk-mkivs.net/forums/t/141240.aspx

I had a similar problem with my vrs and it turned out a couple of bolts had worked loose on the turbo manifold, had new studs fitted and problem solved!

Skoda dealer diagnosed and fixed the problem, maybe worth checking?

His symptoms are classic sign of a leaking SAI pump housing.