Pinging/Knocking/Detonation? Sounds like rocks in the engine on acceleration..
It basically sounds like engine knocking to me. You get on the accelerator and it immediately starts to sound like rocks are flinging around in the motor. As soon as you let off on the gas, and get back on it the sound goes away. Has anyone else had this problem?
Couple of notes: Car is a 2017 C300 Coupe, 2.0L Turbo motor, about 4500 miles. Uses 91 Octane gas (highest available in Tucson, AZ). Tucson elevation is ~2400 ft above sea level. Outside temps around the 80 degree F range. Car is in "Comfort" mode when it happens.
Also, knowing that it's intermittent, there's about a 99.9% chance that the dealership won't experience the problem at all while they have it, and hand it back to us.


