'93 2.8 300E 150K miles. i've got a roaring/whine noise for about the first 30 seconds after start-up which lasts longer if the temp is very cold. However, it's been there for 50K miles! I believe it's the air pump. anything serious? all replies are appreciated.

 

The air pump is to warm up the cat converter, that's why when the car warmed up, the air pump cuts off. it's just annoying noise no major worries, I replaced my at 100k miles.