Check Engine Light and engine whine, 1998 S70 T5

volvoS70FAN · Post by **volvoS70FAN** » 30 Dec 2006, 15:25

Hi there. I have a 98 S70 T5 that recently has developed a problem. The check engine light comes on, but the car still drives fine. The only thing noticeable is a very loud sound coming from under the hood that sounds like a jet engine whining up and then down again. This usually happens a few minutes after starting the car, even if the car is still in park without touching the gas. It is a turbo, and has 93,000 Km on it (Canadian car). My wife drives it to and from work (only 2 km), and the car seldom sees highway driving, especially now that this has happened. Is this a problem with the Turbo? Any advise would be greatly appreciated. Thanks.

Post by **MadeInJapan** » 30 Dec 2006, 15:47

Doesn't sound like the turbo. I would be willing to bet that it's the secondary air pump located under your battery. Water gets in it from condensation when the SAS valve (it's up near the fire wall...looks like a brass mushroom) fails. It is best to replace the valve and also the air pump. You can read up on how to use a VW air pump to replace the one you have in there for cheap in the maitenance data base.

All this said, please have your codes read at a AutoZone or other car parts place (usually for free) and report the codes back here before being conclusive that it's the air pump.

Btw, if it is the air pump, you won't harm anything by driving the car with it making that sound. All that will happen is that you'll burn rich for the first few minutes after your car starts as the pump isn't pulling the exhaust out like it's suppose to. However, if you have an emissions inspection coming up, without this issue being taken care of, you won't pass.

volvoS70FAN · Post by **volvoS70FAN** » 30 Dec 2006, 17:04

Thanks for your help. I'll have the codes checked out and post them. To add to the problem, the service light came on today as well. I guess it's time for an oil change and tune up. At least that light goes off after a couple of minutes.

Post by **JRL** » 30 Dec 2006, 18:35

I would say, definitely the secondary air pump

Leatherneck · Post by **Leatherneck** » 31 Dec 2006, 18:06

Ahh, good tip. My Wife's car has been doing this for some time now. I will have to order the parts and tackle this problem. Could this also throw a P0171 code? Is there any other maintenance that should be done when doing this replacement?

Post by **pfeener** » 31 Dec 2006, 18:58

if the air pump fails it will post a PO410 code. The 171 code is "system too lean (Bank 1)

Post by **MadeInJapan** » 01 Jan 2007, 01:44

and that is a front 02 sensor code but that doesn't necessarily mean that the 02 sensor is bad.

Leatherneck · Post by **Leatherneck** » 01 Jan 2007, 06:01

Thanks, I replaced the sensor not to long ago after looking at it. It was pretty crapped up. Gonna try to see if it has a leak in the vacumn today. Had hoped that maybe this could be the culprit as it has been getting the jet engine whine the OP stated for almost as long as the CEL came on. Gonna check on the connections and lines for the Cruise when I do this repair. Thanks for the help.

Post by **pfeener** » 01 Jan 2007, 06:50

The O2 sensor shouldn't be "crapped up". It should be a sort of even light chocolate brown color. If it's crapped up it usually means there's some sort of contaminate in the exhaust such as antifreeze or if a silicon sealant was used on the engine that wasn't sensor safe. Both conditions will render the O2 sensor inoperative.