2002 Boxster S squeal

[kk2002s]

I have had experience with my SAI pump with a high pitch whine while running. There is a sealed bearing (Images of IMSB dancing in your head) in the pump and guess what the grease dries out. My fix (Researched fixes) was to take the pump apart, pull out the bearing.
Use a grease gun with a needle tip
Slip the needle tip over the bearing seal and pump grease back into the bearing from a few location around the seal.
My SAI pump has been quite for a couple year now.
A lot cheaper than replacing the SAI pump @ $300+
Be careful with the vibration (Rubber) mounts as they can tear in half due to age

[Twin headlight Ernie]

Thanks for the reply kk.
That's exactly what I wanted to hear.
Winter is very near here in Minnesota and I'm sure I can pull it apart and grease it up.
I'm a retired old school mechanic that would rather fix than replace.
I worked at a Porsche dealership for a very short two years back in the early 80's.
I've moved on to bigger and better things but still enjoy tinkering on bikes and cars.

[Twin headlight Ernie]

Could someone give me a explanation of the SAI's function?
What it does and why?
I'd like to get a education on this since I'll be fixing one soon.
Thanks again for the help.
Ernie