Rattle on low gear acceleration and engine braking

[Byngo9]

2014 C4 Picasso B78 1.6 HDI manual gearbox.
If accelerating in 1st and 2nd got a strange rattling noise that settles down as you reach further speed and gears. Quite a different sound (occasionally) if I decelerate in gear ( no brake pedal application), this sound sounds deep and throaty and tractor like ( not quite so much a rattle).

Can't hear any unusual noises at engine idle or just revving engine, or operating the clutch in neutral.

Recent work in last few months has been local garage fitting new clutch and DMF.
Plus me changing timing belt and pulleys plus aux belt and both pulleys. New fuel and air filter and oil filter change

I'm wondering if the new DMF is failing premature or input shaft bearing? Could there be anything related to the new belts?
Been back to garage that did clutch about 4 months ago who said it's not clutch or thrust bearing and doesn't sound typical of the DMF.

Any ideas??

[RichardW]

Driveshaft? Wheel bearing? Exhaust knocking? Engine mount? Difficult to say - if not obvious you might have to wait till it gets worse!

[Byngo9]

Well, the local garage gave it a quick check over on the ramps checking for worn / loose things after a short test drive with me. To my ears, I was happy it wasn't engine noise but I kept thinking transmission related. Garage were confident it wasn't anything clutch or gearbox but coming from the area of off-side front, maybe wheel bearing but nothing like that was obvious at first look. I left the car with them for further investigation and not very confident because I'm thinking "I know what a worn wheel bearing sounds like" and if its suspension, why don't I hear something when coasting, steering or using the brakes , on / off kerbs, over speed humps etc.
Diagnosis was OSF tie rod ball joint and suspension arm bushes (now replaced by Garage). Also said the OSF "crash bar leg" bush worn but dealer only part at circa £270. I'm a bit confused what this part this is? Need to check with them if they mean the Anti-roll bar.

The good news is, the noises I was hearing in 1st / 2nd gear either in acceleration or engine braking have gone. Confidence restored !!

[Rob112]

Good result

[wurlycorner]

That's great news if they've successfully diagnosed it and repaired it for you - I'm similarly surprised that it's suspension bush related, although I have also had situations where strange vibrations on over-run have been due to ball-joints/suspension bushes are worn. I think it's because it caused the tracking to go out, giving tyre scrub etc.