JimmyR

Would pre-ignition ie pinging routinely trigger a CEL? Or would I have to run a diagnostic check and look for fault codes to pick up this sort of problem??
The reason I ask is that I have a stock P31 ie no tune and have noticed what sounds to me very much like pinging under acceleration. It seems to be most noticeable for a brief period at relatively low rpm then settles as revs increase. No obvious loss of performance. I thought it might have been due to a bad batch of fuel when I first heard it but have refuelled several times since with several different fuel companies (all 98 RON) and still hearing it.

Merc63

Pre ignition is not the same as ping (detonation).

The car has a knock sensor that will cut timing I'd it detects ping, so I doubt you are hearing ping.

AMG893

i hear a similar noise too, in similar circumstance, but i hear it more in a tunnel, or when near a concrete barrier, as the noise echoes off that, and if the driers window is open, it can be heard.

I have always said i will record it.

Merc63

Probably the lifters or the cam adjusters. They both can make a clicking noise. The cam adjusters when going bad will produce a rattle or metallic clicking noise.

Diabolis

+1 on both of Merc63's posts above.

nkc

i hear pings constantly in my C63 and if u live in nigeria, am sure u wont mind as our fuel maybe RON 50 , it pings so bad that its a way of life, octane boosters do little to help.

once in a while we get good fuel and the car doesn't ping at all under any load......