Whimpering noise

[dtr1001]

Hello I've been noticing recently a kind of odd noise that I'm assuming is coming from the engine compartment which sounds like a small animal whimpering. (I checked, there is no small animal!). I'm wondering maybe something to do with the air con that I have used a lot recently. Has anyone else noticed a noise like this?

[cheshired5]

Take off the auxiliary belt and if the noise goes away, it's pulley related. Aircon, alternator, tensioner etc.....
What's the belt change history?

[dtr1001]

Thanks. All belts were replaced including timing las December?

[dtr1001]

So you know when you are pulling away, you go from 1st to 2nd and continue to pull away then what I get is this occasional slight loss of power which i would call a flat spot and it's accompanied with this noise so i'm thinking something to do with air intake maybe. The engine is the 1.6d which is running fine other than this. Would a faulty swirl valve make this noise or could it be something else?

One other thing. I have not reset the average MPG recorder for over a year. I do a lot of motorway driving so this used to always hover around 58 mpg which went down a bit when i used the car locally but always back up to 58mpg when i got back on the road again. It's now hovering around 55 mpg so fuel consumption has climbed a little. Related?

Thanks again.

[cheshired5]

Not sure the 1.6 even has a swirl valve.

Have you tried the belt off test?

[dtr1001]

Originally Posted by cheshired5

Not sure the 1.6 even has a swirl valve.

Have you tried the belt off test?

What's the belt off test?

[dtr1001]

Originally Posted by dtr1001

What's the belt off test?

Sorry, i was rushing earlier. I haven't done the belt off test since the noise is accompanied by a flat spot so couldn't see why an auxiliary belt / pulley / bearing issue would cause or be associated with a flat spot but i'm always ready to be educated?

[cheshired5]

If a pulley is seizing, this will place additional load on the engine and could easily create a flat spot at low engine speeds.

Take the belt off.

[nickfole]

Originally Posted by dtr1001

Sorry, i was rushing earlier. I haven't done the belt off test since the noise is accompanied by a flat spot so couldn't see why an auxiliary belt / pulley / bearing issue would cause or be associated with a flat spot but i'm always ready to be educated?

Have been trying to describe the same noise to several garages on my 2010 V70 SE 1.6 Drive. Wimpering sounds about right. General happens with slight hesitancy at 1500rpm.
Could also describe as a springy chuckle sort of sound. Quite distinctive.
I have had no luck with any Volvo garages on this.
Ive driven 70000 miles with the noise. Still doing it at 125000mls.
Note that the EGR failed during which time the noise and hesitancy dissapeared.

Note that Ive had problems with EGR which has caused problems with DPF. Not sure if this is all as a result of this "wimpering".

Any advice would help me too.....

[dtr1001]

Hooray! Someone else recognises the noise. I had my DPF and EGR changed about 6000 miles ago so I'm hoping it's not related to those parts as it cost a few bob to get these parts changed. I had all my belts changed at the end of December last year so was thinking new belts might have put a strain on a pulley or idler maybe?