Metallic Woodpecker Noise

[DSLiverpool]

It will be going in to the specialist (again) but here's what I can tell you about my little robotic bird friend

XC70 diesel 163 2005

Sound can be like a tat tat tat tat tat tat tat like knocking a screwdriver blade on a silencer or just a tat ........ Tat tat ....... Tat ...................................
Hardly does it when cold but when hot it's "turned on"
Not speed related
I can't make it happen by steering side to side
Possibly it does it more in deceleration but that might be in my head

These cars have an issue with prop shaft hitting the exhaust - it's not that, not that type of noise plus they already modified the bracket.

I was thinking maybe the CAT ?

Any info appreciated, it's not in till next week but once diagnosed I will update.

[Smokehead]

Only time I had a noise like that was in my V70 when the power steering fluid was a bit low.

[DSLiverpool]

Sounds like it's coming from the back or middle of the car, steering just had flush and additive

[guitarcarfanatic]

DMF?

[DSLiverpool]

guitarcarfanatic said:

DMF?

It's automatic - I'm no mech but DMF is manual ?

[morgrp]

Could be a knackered propshaft bearing if its coming from the middle/rear of the car
Or a seized rear caliper that is seizing on when hot and freeing off when it cools down

[IanCress]

I had a similar noise in my old 2003 V70 which turned out to be an ABS sensor. The sensor was failing and was causing the car to activate the ABS on every wheel rotation. Eventually it failed and put the ABS and traction control lights on.

[DSLiverpool]

It's not been in yet as car just isn't being used but they already did the exhaust hanger as a update when it was in for a shakedown.
They didn't notice the metallic woodpecker as it needs a good few miles before it starts wouldn't a propshaft do it from start ? Abs maybe but doesn't feel it, transfer box is only used when slippy ? Or is it all the time and connects drive at the rear when slippy ? Will take in next week

[MJG280]

I had a similar noise from the front of an S60 2005 and it was both ABS rotors on the drive shafts had split because of rust on the driveshaft so the ABS was working intermittently. There was an intermittent message for ABS Service Required for that one.

Also previously to this had, at speed, a chattering noise which was the rear caliper being partly seized after a pad change so was not moving properly and left a gap between the pads and disks so that the pads flapped about.

[mybrainhurts]

DSLiverpool said:

Sounds like it's coming from the back or middle of the car, steering just had flush and additive

Check under the boot floor for naked leprechauns. They get cold at this time of year.

[DSLiverpool]

Not fixed yet, a thump sound was the detachable tow bar in the wheel well but the "metallic woodpecker" only happens on deceleration / throttle off making me think the exhaust is flexing with the engine?

[Yodafone]

If it happens on acceleration I think it could the manifold gasket, as my S60 had did this rattle sound on acceleration it was vibrating against the engine.

[DSLiverpool]

Yodafone said:

If it happens on acceleration I think it could the manifold gasket, as my S60 had did this rattle sound on acceleration it was vibrating against the engine.

It's totally random,on Tuesday its going in again for a check over.
I've never had anything so perplexing !