Is this a faulty vac pump???

Is this a faulty vac pump???

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Discussion

Ydraiggoch

Original Poster:

2 posts

1 month

Friday 3rd September
quotequote all
Hi,

I'm hoping someoone might be able to give me some help with diagnosing what the problem is here.....

I have a Volvo XC60 (2012 - D4)

When the car is running idle, all sounds fine unless you remove the Oil filler cap and there is a distinct 'popping' noise - I say popping noise as this is what people on Youtube describe it as.

Put the cap back on, and the sound goes away.

https://youtu.be/7kyEyPIOTtE

Now, if you press the brake pedal, then the noise can be heard without removing the filler cap. Once you release the brake pedal, then the noise slowly dies away (again, this is all from idle - car stationary).

https://youtu.be/wWQ563BkIzw

after further investigation, I have pinpointed the noise to this;



I think I'm right in saying that this is linked to the Exhaust Flap?? When the brake pedal is released the little ball goes up and down making the noise, until eventually its pulled up. This unit is linked via a hose which comes from the Vac pump to a Sensor, then from the sensor to this device.

It's almost like there isn't enough vacuum to pull the (shut?) the flap? If I remove the hose to the Flapper unit, then the noise goes away, but the ball / rod stays down (open?).
The vacuum from the pump feels like its pulsing ie not a constant vacuum like a vacuum cleaner (if you know what I mean).

I'd be grateful if anyone was willing to share their thoughts on this,
Is the car still ok to drive?
What other checks can I do to diagnose whats causing this?
What's likely needing replaced here?

MAny Thanks in advance for any advice.

GreenV8S

29,023 posts

254 months

Friday 3rd September
quotequote all
What you're describing is a vacuum pump. It shouldn't surprise you that it makes a noise when it is working. I suggest you stop fiddling with it.

Ydraiggoch

Original Poster:

2 posts

1 month

Friday 3rd September
quotequote all
I don't believe the noise to be the VAC pump. The Noise appears to be coming from the Exhaust flap which is 'flapping' up and down when the brake pedal is released.

I wouldn't be 'fiddling' with it if I thought the noise was normal. This has only recently become apparent, therefore, something has changed.

Regards

LimSlip

757 posts

24 months

Friday 3rd September
quotequote all
The vacuum pump exhausts into the cam area, this is what you can hear. When it's pumping more air (e.g. you just applied the brakes) then it gets louder. That said it should be relatively quiet under normal conditions, so it's possible you have a vacuum leak.

paintman

6,625 posts

160 months

Friday 3rd September
quotequote all
Not being funny but it sounds like it would be worth finding an indy Volvo specialist in your area and letting them have a look at it.