2000 V70R Whining/Buzzing Noise in Engine Bay

[abscate]

Rhythmic 3 Hz burst of 500 Hz metallic sound. That fancying language makes me technical And is absolutely no value in solving the problem.

I would get a pipe stick in my ear and follow the end around the engine To locate the source that way. When it gets loud , you are close

[bmdubya1198]

Yeah, I'll have to poke around a little more and see if I can narrow it down.

But what's the point in describing problems if you can't throw some technical speak in there?

[abscate]

Rhythmic 3 Hz burst of 500 Hz metallic sound. That fancying language makes me technical And is absolutely no value in solving the problem.

I would get a pipe stick in my ear and follow the end around the engine To locate the source that way. When it gets loud , you are close

It’s more like 1 Hz

CVVT solenoid
tCV
Purge valve

One of those. Pull wire on each while idling, see if it’s stops

[RickHaleParker]

Rhythmic 3 Hz burst of 500 Hz metallic sound. That fancying language makes me technical And is absolutely no value in solving the problem.

I would get a pipe stick in my ear and follow the end around the engine To locate the source that way. When it gets loud , you are clos

It’s more like 1 Hz

Human hearing range is 20-20,000 Hz. A few people can hear as low as 15 Hz.
Unless you have superman hearing, you are not hearing 1 & 3 Hz.

[bmdubya1198]

I guess we just have super human hearing!

[erikv11]

Rhythmic 3 Hz burst of 500 Hz metallic sound. That fancying language makes me technical And is absolutely no value in solving the problem.

I would get a pipe stick in my ear and follow the end around the engine To locate the source that way. When it gets loud , you are clos

It’s more like 1 Hz

Human hearing range is 20-20,000 Hz. A few people can hear as low as 15 Hz.
Unless you have superman hearing, you are not hearing 1 & 3 Hz.

According to the post, he's hearing 500 Hz. He's using 3 Hz and 1 Hz to refer to how often the rhythmic, 500 Hz sound occurs.

There, now I have also contributed more of nothing to solving the problem!

[wizechatmgr]

At what RPM is this car idling when we hear this noise? My thought is valve train or a nasty vac. leak.

Abscate had a weird one where the hose going to a check valve would suck closed but then blow open while it had pressure... Made for some really weird symptoms. Hose looked like one that a cartoon character put an acme bomb in... Split on both sides right down it for several inches.

[bmdubya1198]

It's idling totally normal, about 850 RPM. I heard it LOUD earlier when my cousin pulled it off the alignment rack at his job, but it went away as usual. It's very weird, it just comes and goes when it pleases.

I think I know the hose you're talking about, the one under the intake manifold that goes to the check valve and then another hose to a vacuum tee. That hose was split in the same way when I first bought this car. I think just about every vacuum hose on this car was split like that, plus the ETM was bad. I have no idea how anyone drove this car before all the work I did, it was an absolute wreck mechanically.

[bmdubya1198]

Checked it out again today, and I knew for SURE it was the ETM when the car didn't start (for some reason it does that sometimes when I clear codes in VIDA) and the ETM continued whining. Once I got it running after a few minutes, it continued as usual.

Now I'm feeling like my other issues are related to an ETM wiring issue. I know the ETM itself isn't the problem because I've replaced it 3-4 times already.

[RickHaleParker]

Now I'm feeling like my other issues are related to an ETM wiring issue.

There are known issues with that ETM/ETB loom.

"When there are diagnostic trouble codes stored for the ETB, it doesn’t necessarily mean that the ETB is defective. A large number of failures are caused by poor tension on the ETB connector plug. Volvo acknowledged that problem and released the ETB harness repair kit PN.31409380."