Searched, found this post : https://www.matthewsvolvosite.com/forums/viewtopic.php?f=1&t=27028&start=0&hilit=secondary+air+pump

Indeed it does sound like the secondary air pump. I will test it by unplugging it, then try to find one at a junkyard as I am already spending money sending my ABS module ...

Manual:

http://apps.volvocars.us/ownersdocs/199 ... 70_000.htm

I've been pretty religious about the oil, changed every 3-4 K with semi-synthetic, but I bought the car with 91k miles on it, so who knows how it was treated before me? So it may well need a flush. I know I need to do the PCV system.

I'm pretty certain it's not the blower; I can hear it whine from ...

My turbo on my 98 V70XC has started making a noise. I notice it when the engine is cold and I am just starting out of my driveway. It seems to wind up once and then I no longer hear it at road speed. It also occasionally kicks in when the car is just sitting idling. The car was in my garage the ...