2000 V70R Whining/Buzzing Noise in Engine Bay

Post by **bmdubya1198** » 15 Apr 2019, 07:55

While I try to diagnose a myriad of other issues with my V70R, I think I'll see if anyone thinks this is related to my low boost issue or whatever other problems. I've noticed this noise since before I modified anything, so I'm pretty positive this isn't my doing!

There is this whining/buzzing noise that I've noticed around the area of the power steering pump. It's very electronic-sounding, and I can't figure out what it is. When I removed the timing cover and listened, it didn't sound like it was related to the CVVT hub or solenoid, so I think I can rule that out. I don't think it's the ECU (but I guess anything's possible?). Initially I thought this was my fuel pump, but as I looked into the noise I discovered it was coming from the engine bay and nowhere near the fuel pump.
The noise isn't constant. It will start doing it for a few minutes here or there, but I have noticed that there are times when it does not do it.

I'm going to attach a video, and you can hear it pretty clearly in the video. It's a high-pitched whining/buzzing noise.

Post by **RickHaleParker** » 15 Apr 2019, 12:02

Secondary Air Pump.

Post by **jimmy57** » 15 Apr 2019, 12:54

That car wouldn't have the secondary air pump as CVVT effectively replaced it starting with 99 year model.
Is the noise variable with engine speed? I can't hear it in the video. The crankcase vent nipple on intake is on that end of intake manifold and the throttle can make air noises of various pitches. In gear and a/c and headlights on should make throttle open more and affect vacuum amount and throttle opening (more throttle and less vacuum). Turning everything off and putting it in Park will reduce throttle opening and increase vacuum. The evap purge valve can make noise and would not be consistent when idling as it is not always operated at idle. It is under intake but above starter further away from the power steering pump.

Post by **RickHaleParker** » 15 Apr 2019, 13:27

jimmy57 wrote: ↑15 Apr 2019, 12:54 That car wouldn't have the secondary air pump as CVVT effectively replaced it starting with 99 year model.

What am I missing?

Volvo part number 9179271: Secondary Air pump.

Applications:

Volvo C70 Convertible 1998, 1999, 2000, 2001, 2002, 2003, 2004
Volvo C70 Coupe 1998, 1999, 2000, 2001, 2002
Volvo S70 1998, 1999, 2000
Volvo V70 1998, 1999, 2000
Volvo V70 XC 2.4l 5 cylinder Turbo 2000
Volvo V70 XC 2.5l 5 cylinder Turbo 1998, 1999

Post by **jimmy57** » 15 Apr 2019, 15:53

They may put them in somehwere in the world but in US they dropped air pumps with intro of CVVT. The air pump only worked for a minute on cold start to pump air into exhaust to afterburn fuel in the exhaust and it sped up O2 sensor warm up and catalyst warm up. With exhaust CVVT you advance exhaust valve opening several degrees before BDC while combustion is still going and retard ignition timing to start combustion later. These two will cause active flame exiting the opening exhaust valves which will ignite tail end of the gsses of the last exhausted cylinder and assure the unburned fuel that could be there is burned to reduce hydrocarbons. The increased flame in exhaust does the sensor and catalyst heating too. Air pump systems sucked and failed a lot. CVVT is not without issues but is way more reliable than the air pumps.
The 2.9 S80 non turbo for 99-> and the 2000-> 2.4 non turbo 5 cylinder have intake CVVT only (until they went with dual CVVT) and the intake cam is retard together with retarded ignition timing to get a little bit of the same action with no air pump.

Post by **bmdubya1198** » 15 Apr 2019, 18:16

Nope, no air pump on '99+ P80s. My '98 has one, and it's on the driver side.

It does not vary with the engine speed, it sounds like some sort of electronic part. It's an oddly pulsating electronic humming/buzzing. Almost like an old fluorescent light bulb, except it has some ups and downs, almost like a wave tone, if you will. It's hard to describe.
I actually just replaced the PCV parts, and those are all sealed tight. The banjo bolt on the intake manifold is tight and not leaking, as far as I know. I ordered the updated version with the check valve, I'm definitely not looking forward to putting it in.

The evap purge valve is good, I just replaced it since it was clicking. A/C and headlights were off, but I don't think the A/C works in this car. I'll have to take a look at the compressor to make sure everything is hooked up properly.

Post by **abscate** » 15 Apr 2019, 18:38

Isolate the source with a rubber hose and your ear. It’s really hard to do subtle sounds over the Internet.

No air pump on either 99 in My fleet

Post by **RickHaleParker** » 15 Apr 2019, 18:41

Fashion a Ear Trumpet see if you can isolate where it is coming from. A clean transmission funnel works.

No secondary air on my '03 X40 S40, '98 P80 C70 has one. '97 P90 S90 has one.

Post by **bmdubya1198** » 15 Apr 2019, 21:08

Yup, my '98 S90 has one as well.

I have a mechanic's stethoscope, I'll have to poke around with that can see if I can track it down. It can definitely tough to try to point out a particular sound to someone, especially over the internet!

Post by **scot850** » 16 Apr 2019, 17:20

The ETM initialises when you switch the ignition on. It whines and buzzes but for only a few seconds or so. If it continues to do so it be it is failing.

Neil.