Warm Engine startup Knock / pinging 😢
Thread Starter
Junior Member
Joined: Mar 2024
Posts: 46
Likes: 2
c63 w204
Warm Engine startup Knock / pinging 😢
Hello,
My 2012 c63 has 48,000 miles on it, totally stock car.
Only on warm-start up just for 1 sec as the car is about to start i hear a loud pinging sound like the car knocks asif it has bad fuel or bad spark plug, it does not sound like lifter rattle or tick.
this knock/ping only happens if the car is warmed up Never on cold start and is very audible from in side and our side.
https://youtube.com/shorts/p6peb_atfyU?si=oHxoyYSyO_tev8Ao
car idles very good and drives normally not pinging even at wot or accelerating but i do hear a faint bussing sound coming from the right side of the cabin as I accelerate slowly from 2500 rpms in gear only never when i rev in neutral gear or parking, even if i rev it i don't hear any knock its just only warm startup.
please help me figure out what this is as im really worried about it .
thanks
My 2012 c63 has 48,000 miles on it, totally stock car.
Only on warm-start up just for 1 sec as the car is about to start i hear a loud pinging sound like the car knocks asif it has bad fuel or bad spark plug, it does not sound like lifter rattle or tick.
this knock/ping only happens if the car is warmed up Never on cold start and is very audible from in side and our side.
https://youtube.com/shorts/p6peb_atfyU?si=oHxoyYSyO_tev8Ao
car idles very good and drives normally not pinging even at wot or accelerating but i do hear a faint bussing sound coming from the right side of the cabin as I accelerate slowly from 2500 rpms in gear only never when i rev in neutral gear or parking, even if i rev it i don't hear any knock its just only warm startup.
please help me figure out what this is as im really worried about it .
thanks
Last edited by wheelspk2131; Mar 24, 2024 at 08:23 AM. Reason: Manage attachment
Thread Starter
Junior Member
Joined: Mar 2024
Posts: 46
Likes: 2
c63 w204
Thread Starter
Junior Member
Joined: Mar 2024
Posts: 46
Likes: 2
c63 w204
Newbie
Joined: Mar 2020
Posts: 10
Likes: 5
2010 W212 E63
Hi OP,
I think I heard a chirp/chirping sound just before it started. I have this problem on my M156 when the fuel injectors need cleaning/replacement. Check your fuel injectors for leaks/dripping. Normally I just change all 8 injectors and i'm good to go again. If you have a good fuel injector shop near you, you can have them test and clean them. I have also gotten away with just doing cosmetic cleaning as well.
Regards
Kamal
I think I heard a chirp/chirping sound just before it started. I have this problem on my M156 when the fuel injectors need cleaning/replacement. Check your fuel injectors for leaks/dripping. Normally I just change all 8 injectors and i'm good to go again. If you have a good fuel injector shop near you, you can have them test and clean them. I have also gotten away with just doing cosmetic cleaning as well.
Regards
Kamal
