mkawass

Hello Guys,

I just bought a CPO 2014 c300 4matic with 24k miles on it. everything is running well. I noticed that when the car is idle at park and i hit the accelerator to 3000 RPM, then remove my foot from the accelerator, i feel a small vibration. also when putting the car on drive while holding break and accelerating, then engine rises a little bit from driver side. i dont feel any vibration when the car is just at parked or while driving or shifting gear.
Took it to dealer, he said they lifted the car and check all engine mounts plus transmission mounts, not issue. he said because the car hydroponic mounts it is normal to feel it in that specific case. He offered to test a couple vehicles same model same year same mileage, and indeed when idle and just hitting the accelerator then releasing i tiny vibration is felt. i am trying to believe them!!!
Can anyone comment on this please?

Thanks!

tekfoc

Mercedes service dept makes good money on warranty repairs.
if the engine mounts were bad they would love to replace them and anything else they find.
what is meant is the motor mounts are internally liquid filled, very common on other car makers.

mkawass

Thank man. So this is totally normal due to the nature of these mounts been liquid filled?

tekfoc

yes

mkawass

Ok, great! makes sense especially after letting me test cars like mine showing the same results. You seem to know your game man! One last question for you then, bonus question!

when the Car Fan is on, i feel a small tiny vibration when my foot is on the break, not felt at the accelerator. nothing loud , just a small vibration, and it goes away when i turn the fan off. any what is it? or is just the air fan been placed close to break? or this should not happen?

Thanks a lot!

tekfoc

that's because the brake pedal is physically connected to the fire wall and thru to engine bay were it's then connected to a brake power booster then brake master cylinder.
sound waves easily transmit in reverse order.
gas pedal is just mounted to fire wall that's it.
it's a fly by wire control system.

good luck.

mkawass

Damn! Mercedes could have done better man! my Honda doesn't have all this! So again, it is all good?

tekfoc

it just of matter of adding additional insulators .
it may be a Mercedes but its far from perfect.
I had a Honda and even Honda is far from perfect.
but fantastic on the pocket.

mkawass

Ok. are you saying to should add insulators?

tekfoc

just enjoy it .
drive it.
I'm talking in engineering mode as what the manufacture could of done.