1998 V70 Does the Air Pump Actually Do Anything?

PierogiSmash · Post by **PierogiSmash** » 20 Mar 2014, 08:53

Hi All,

My airpump has started to sound like a vacuum grinding up a cat. Of course, the noise only lasts a minute or so, then it stops and all is well. I guess I have 2 questions:

1. What does the air pump do?

I ask this because the car runs no different before the thing kicks in and no different after it shuts off.

2. If nothing changes regardless of this thing being on or off, do I actually need it? Can is be simply unplugged and ignored?

Some people may gasp and sputter at that last statement, this is an honest question looking for a direct answer...

Thanks.

youropeen · Post by **youropeen** » 20 Mar 2014, 09:11

It can be removed, but only after you do an air pump delete modification to the ecu. It will trigger the check engine light if you don't do the mod. It's very simple if you follow the directions here.

http://volvospeed.com/vs_forum/topic/14 ... with-pics/

My pump died a few years ago and I was driving it with the cel on. I had to reset it before every yearly state inspection.

I did the mod last summer and have not had any issues since.

Post by **rspi** » 20 Mar 2014, 09:18

Do you want a DIRECT short answer. That would be YES.

The primary purpose if the pump is to keep the CEL out (as viewed by most people). If you unplug it, the CEL will come on and you will not pass state inspection. There is a way to disconnect it and bypass it in the computer. You should Google "Volvo S70 SAS Delete".

It helps send air to the motor when the motor is cold. Only works for a minute or two.

Welcome to the forum.

PierogiSmash · Post by **PierogiSmash** » 20 Mar 2014, 10:01

I figured it didn't do anything. Thanks for the info guys. This site is great...

Post by **Fish stick88** » 20 Mar 2014, 12:57

I had the same problem. Mine would turn on, and sound terrible. Well. After striking it with fear, and planning to modify it in a month or so, it either "fixed" itself, or completely seized, or burnt up. Either way. No CEL, and no problems, and most importantly, no "sound(s) like a vacuum grinding up a cat."

Post by **erikv11** » 20 Mar 2014, 16:16

The direct, short answer IMHO is NO - the air pump is unimportant and engines that are otherwise identical may or may not have an air pump.

The air pump is strictly an emissions gimmick, it has nothing to do with warming the engine.

Get rid of it, the first reply to this thread has the info you need.

instarx · Post by **instarx** » 20 Mar 2014, 16:30

erikv11 wrote:The direct, short answer IMHO is NO - the air pump is unimportant and engines that are otherwise identical may or may not have an air pump.

The air pump is strictly an emissions gimmick, it has nothing to do with warming the engine.

Get rid of it, the first reply to this thread has the info you need.

An emissions "gimmick"? No. It is an emissions device that reduces emissions during the first few minutes after a cold engine start -- when emissions are the highest. It increases exhaust gas temperature and brings the catalytic converter up to operating temperature faster.

Post by **taxi** » 20 Mar 2014, 16:45

+1. It simply pumps air (oxygen) into the exhaust to ignite the catalyst converter, or get it to operating temperature faster.
That's also why it can only run for about 180 seconds, soon after that the oxygen sensor comes into play and the ecu would not like that.
later versions also runs the pump for a second or two after no less than ten minutes of driving, at idle, to diagnose pump by looking for reaction of oxygen sensor.
The ecu only runs the pump if the engine temperature is between -12 and +30 degrees Celsius upon startup.

Post by **jreed** » 21 Mar 2014, 05:00

Taxi-- Thanks for posting that information... I always wondered why my '97 855 GLT will turn on the air pump after the car has been driving for a short time, generally just after coming to a stop at a traffic light and idling.

Post by **rmmagow** » 21 Mar 2014, 06:29

I replaced mine with a cheap aftermarket part. Turned off the CEL, makes no noise. There's the silver can thing at the back of the motor that may need to be replaced to if it's stuck open, again, any cheap after market part is OK. SAS delete is pretty easy to do, I didn't do it only because I didn't trust myself and the parts to fix it didn't cost a fortune (genuine would be killer priced though). The job also gave me a chance to clean up under the battery tray, find my charcoal canister, find the shifter control thing and generally bond with some obscure mechanical, electrical, and vacummicable things. Mickey-Mouse parts have been fine for 60K miles.