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.

[DSLiverpool]

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

[DSLiverpool]

guitarcarfanatic said:

DMF?

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

[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

[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?

[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 !