Some of you are going to start thinking I don't have my car serviced

I'm now on my third noise. I have the clonking, and the droning wheel bearing. Now I have a third one for you experts.

On starting the engine, I'm getting a whirring chattering noise for the first 30 seconds or so.

It's not the hydraulic tappets.

It's not the petrol pump (I don't think)

It sounds like the injectors ticking, or a blow in the exhaust, except louder. However after the first 20 or 30 seconds, it stops abruptly, and everything returns to normal.

It used not to do this. It only does it when starting from cold.

Any ideas?

Sounds like the seconadry air pump to me.

The rivets holding the plastic casing together have a tendency to corrode away, allowing the compressor housing to split, causing the noise you have described.

No need to fork out silly money on a new one though, you can fix it (DIY guide here somewhere). Just a case of removing the pump and drilling out the rivets, and replacing them with bolts to keep it sealed.

Found the guide! Step-by-step guide for repairing the Secondary Air Pump (with pictures) - uk-mkivs

It's nothing major anyway, mine is a bit noisy, but I haven't bothered to do anything about it yet!

I agree with Bodge. Hope his info helps you!

Fab! I'll see if I get time to take a look at that at the weekend. Thanks guys.

Update. Sorted. Some 2BA bolts and nuts, and some spring washers, total cost £1.86, and some bits left over. Did it without removing the pump, you can rotate it all the way still in the mounting. Many thanks.

That DIY has just saved spending around £350 for a new pump. :shocked:

They should be ashamed of themselves, the rubbish it's riveted together with initially!

Update. Sorted. Some 2BA bolts and nuts, and some spring washers, total cost £1.86, and some bits left over. Did it without removing the pump, you can rotate it all the way still in the mounting. Many thanks.

Nice one! I'll need to do mine soon....