Clicking noise on acceleration

[///AMG55]

Hi all,

I have an S500 (W220) and am hearing faint clicking noise on acceleration. Would be great if I could get some advice on what may be the cause of this noise. Please find below all the details relating to this noise:

- Faint clicking noise on acceleration only
- Noise goes away as the car get some speed.
- More pronounced when engine is still cold.
- More noticeable when accelerating uphill and cold
- Noise is still here when engine is warm but much less noticeable
- Does not occur when revving on idle.
- Can only be heard inside the car with windows closed.
- Comes behind the dashboard area

I have tried to make a video but the noise cannot be heard on the video because the clicking is very faint.

Would really appreciate if anyone could help me.

Thanks
Jake

 

[Deleted member 126251]

your exhaust is not making enough noise.......

 

[merc85]

Cracked exhaust manifold?

 

[///AMG55]

Was thinking of cracked manifold as well.

Does anyone have any tip to check whether manifold is cracked?

Thanks

 

[Teego]

Contaminated fuel? Pinking?

 

[John]

Pinking?

This was my first thought.

Last time I had it is was a rattling sound although I knew it was pinking. More pronounced when more demand and hot.

Was in an M3 Evo when nothing greater than 97RON was available but the car needed 98RON.

Was fine on 98RON once finally available at Shell and Tesco in the early noughties.

 

[RichardF]

Worth checking your flex discs, my front one failed, it started as a click under load.