I have a 04 Disco with a strange problem. When I cold start there is a loud squealing noise. The noise is coming from a motor or fan enclosed in a small plastic round case in the engine compartment in front of the pasenger seat. Im guessing ac compressor? The ac and heat works fine so it may be going out or it's not that part. Any ideas, also any ideas on repair cost

 

Your SAI pump motor is either very dirty or failing and needs to be cleaned or replaced.

 

that's it! any ideas on where to get one affordably and how to on how to (step by step) replace?

 

Here's page from the RAVE, the free factory tech manual set. Whole thing is a download in my signature, you will want this on your PC.

Here is one source. Discovery Secondary Air Injection Pump

Here is new Pump Secondary Air | Land Rover Engine Parts at RoverParts.com

As much as I love salvage yards, a used SAI pump will eventually have the same problem you have now. But if you can get to a u-pull-the-parts junk yard, $25 - $40 for a heater fan (that's what they will think it is) beats $400+ for a new one.

Note: there is a filter inside you can change. And the 04 pump is not the same as an 01, for example.

 

Great info, I will definitly call some local junkyards to see if they have some discos to save a buck!! If not 175 is not a bad price. I found a site that has a step by step replacement and it looks simple to replace.

 

The RAVE manual page is not enough? They have a lot more in the manuals.