98 S70 : For a while the service light would occassional come on, now that went off & check engine light is on..there was a "pump" sounding noise that happen in the winter time. Ran a code search, found out it's the air pump. I'm not hearing the noise anymore. I'm holding off on replaceing it. Is it necessary to replace immediately?? What would happen if I didn't replace it?? Thanks:)

The air pump help heat the car up first thing in the morning.
You should replace it pretty soon.

What will happen if it breaks on me and how will I know it went? I know these may be silly questions, but I'm glad there is something like this where I can go to, it is obvious that I have no idea..there really isn't someone where I can go that knows about this car, thank you so much

Your welcome.

If you don't hear it anymore then it isn't working.
2 things happen to the air pump motors.1. Either it fills up with water and shorts out the motor and the relay.
2.The battery leaks and leaks acid onto the motor and shorts it and the relay out.

http://www2.autopartsauthority.com/parts/autopartsauthority/wizard.jsp?year=1998&make=VO&model=S70-T-002&category=B&&part=Air+Pump

Here is a company that sells it.It is pretty expensive but cheaper than the dealer.

ANGEL,

I replaced the Air Pump on my 98 S70 several months ago. The Tech and I discussed this problem in a previous message:

http://www.volvoforums.com/m_3175/tm.htm

During my searches online, for a new Air Pump, I discovered that many different merchants were selling the exact same pump (Part # B6010-113076) for a different price dependent on what Volvo model it was listed under. I did a Google/Froogle search for the Part # and found it for $309, instead of the $389 they wanted when I searched for my specific car. Just checked a few minutes ago and I found it for $325. Just wanted to pass this along so that you don't spend more than necessary when looking for parts.

Don't forget to get new hose clamps before you start to replace the air pump. I discovered during my install that the factory clamps are the crimp on one-use kind.

Good Luck.

Air Defender