407 loud thumping noise under the car when driving over bumps [not lower ball joints]

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FlorianPaun
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Joined: 03 Mar 2021, 00:30

407 loud thumping noise under the car when driving over bumps [not lower ball joints]

Post by FlorianPaun »

Peugeot 407 from 2004, 2.0 HDI, 6 Speed Manual, 66.000 km (yes, really).

I get a short loud thumping noise when I drive over bumps. It is louder when driving at low speeds (<30 km/h). It doesn't sound like it's coming from a wheel, but rather from the middle, I'd say between the front seats and the engine.

I brought the car to a mechanic and after checking it they said it's the lower ball joint from the front right wheel. Had it replaced but the noise is still there.

I've just noticed today that I can also hear the noise quite loudly when I put the car in gear and release the clutch just enough so the car starts to move and keep it there. I noticed this when I put the car in reverse to park it, I needed to go really slowly so the clutch was maybe 50% still depressed.

So before I bring it back to the mechanic, what do you think it could be? Engine/Gearbox mounts? Exhaust pipe hitting something?
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GiveMeABreak
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Re: 407 loud thumping noise under the car when driving over bumps [not lower ball joints]

Post by GiveMeABreak »

Hi

Have a look at my posts below - the 407 has the same setup, and I suspect it will be the same bush as mine that is highlighted in the diagrams. The weight of the car on braking or falling back after a hump or harsh take-off causes the sliding on the lower pivot support when the bush has worn. You will find it hard to replicate unless it is on a 4 post lift and using some strong pulling pushing to get it to clunk - so don't be surprised if you can't replicate it. The mechanic trying to move mine was built like 'Arnie' and he had a job to slide it - but it was obvious was he managed it. As said, PSA don't sell the bush separately, but these can be bought on the aftermarket very cheaply and can be refitted.

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