I didn't buy one.
I got spooked by the guy giving me information that was contradictory to the dealer for the years relating to specific model years and pumps.

Plus my smog isn't due until the end of the year.

 

What year Discovery do you have?

 

I bought and installed a re-built air pump and it solved my problem. The one I bought, is below. It fits perfectly and costs $139. You have to send your used one back as a core.

Landrover Discovery 1999-2004 Secondary Air Pump Rebuilt - Rebuilt Air Pump.com

I no longer have an extremely loud blower noise at start-up! The install takes about 20 minutes (5 bolts).

The filter on my old one was in perfect condition, so I am assuming it was the bearing.

 

Hi all, I have a D2 2004 V8. I also have a louder noise in the morning, that goes away after about 1 minute. I understand this is normal (though earlier I didn't have this noise). Now I also have a Check Engine light and the garage says the diagnostics show "Secondary Air Pump" problem. What should I do? BTW, I had the light reset, but the light comes bach on after a few minutes. What should I do?
thanks

 

Just popped P0418 04 D2 w/SAI- SAI initiated after driving 3 miles and began its normal screaming routine. Turning it off again and the fault is sustained with SAI staying engaged. Can i run with it temporarily like this or unplug it and be ok ( understanding that cold starts might be different)