I was looking for some help.

I have a 2000 discovery 2 series 2, with 96 thousand miles. When i start the car and the car has been sitting for more then 10 hours. there is a high pitch noise coming from right inside the fire wall (on the engine side)on the passenger side that goes for like 3 minutes. but once the noise stops the car runs fine. somtimes when the car is making the noise it idels rough. i think it may have somthing to do with the smog-pump or an o2 system. i recently got one of the two o2 sensors replace. the check light comes on every once and a while but then goes back off.
--sorry this is soo long. but i could really use some help
Jon

 

Sounds like your Secondary Air Injection pump is starting to fail. They do make quite A bit of noise when started cold. But if it is squealing, it's done. Could also be your SEL light problem.

 

Well the pipes running the unit making the noise, run to each side of the engine, right about where the spark plugs are located. could that be the secondary air pump? what purpose does that have? after it stops making noise the car runs fine.
jon