SL55/63/65/R230 AMG: Knock coming from under rear end
Thread Starter
Newbie
Joined: Apr 2021
Posts: 4
Likes: 0
SL55 R230
Knock coming from under rear end
Hello guys, i purchased a stock SL55 02', 150k kms in january, i did some things (ic pump, soft trunk close, battery leakage from teleaid), but now i would like to take care of this weird sound.
Car is running perfeclty fine i guess, engine and transmission, abc ok. I can hear a knock coming from under and behind the seat, not from the trunk. It's like something hitting the frame with a little hammer, only when i am turning. No sound when i ride on a bump, no sound when i brake or accelerate (i think). When i go to the left then to the right, clunk. Another thing i noticed, when i stop the engine after i drive of atleast 20min, i can hear this same sound (i guess) under the car. I can hear it clearly. It's like hot metal cooling down after a ride if you know what i mean but loud. Is is normal ? I could make a video if needed.
I thought of a relay (if there is) inside the end of the gearbox, of something moving freely but i have to go under the car to check this.
Thanks for your help !
Max
Car is running perfeclty fine i guess, engine and transmission, abc ok. I can hear a knock coming from under and behind the seat, not from the trunk. It's like something hitting the frame with a little hammer, only when i am turning. No sound when i ride on a bump, no sound when i brake or accelerate (i think). When i go to the left then to the right, clunk. Another thing i noticed, when i stop the engine after i drive of atleast 20min, i can hear this same sound (i guess) under the car. I can hear it clearly. It's like hot metal cooling down after a ride if you know what i mean but loud. Is is normal ? I could make a video if needed.
I thought of a relay (if there is) inside the end of the gearbox, of something moving freely but i have to go under the car to check this.
Thanks for your help !
Max
Hello guys, i purchased a stock SL55 02', 150k kms in january, i did some things (ic pump, soft trunk close, battery leakage from teleaid), but now i would like to take care of this weird sound.
Car is running perfeclty fine i guess, engine and transmission, abc ok. I can hear a knock coming from under and behind the seat, not from the trunk. It's like something hitting the frame with a little hammer, only when i am turning. No sound when i ride on a bump, no sound when i brake or accelerate (i think). When i go to the left then to the right, clunk. Another thing i noticed, when i stop the engine after i drive of atleast 20min, i can hear this same sound (i guess) under the car. I can hear it clearly. It's like hot metal cooling down after a ride if you know what i mean but loud. Is is normal ? I could make a video if needed.
I thought of a relay (if there is) inside the end of the gearbox, of something moving freely but i have to go under the car to check this.
Thanks for your help !
Max
Car is running perfeclty fine i guess, engine and transmission, abc ok. I can hear a knock coming from under and behind the seat, not from the trunk. It's like something hitting the frame with a little hammer, only when i am turning. No sound when i ride on a bump, no sound when i brake or accelerate (i think). When i go to the left then to the right, clunk. Another thing i noticed, when i stop the engine after i drive of atleast 20min, i can hear this same sound (i guess) under the car. I can hear it clearly. It's like hot metal cooling down after a ride if you know what i mean but loud. Is is normal ? I could make a video if needed.
I thought of a relay (if there is) inside the end of the gearbox, of something moving freely but i have to go under the car to check this.
Thanks for your help !
Max
maybe your transmission mounts/suspension
there are some mounts everywhere on this car that must be replaced especially if your car is a 2002
Junior Member
Joined: Mar 2007
Posts: 34
Likes: 18
I'm in the midst of troubleshooting what I think is the same noise on my 03 SL55 w 33k mi. It's a faint knocking—a slightly metallic noise coming from behind the seats either under the car or behind the rear bulkhead. I initially thought it was a tick not unlike an exhaust cooling but it's too rounded a sound and mine is also rhythmic (about every 20 secs). I'll hear it for awhile after shutting off the vehicle, maybe up to an hour. I suspect it makes noise while i'm driving or when the car is on, it's just not as apparent with engine and road noise going on.
I had the car up on my home lift, immediately after driving and isolated the noise to this spot:
It's coming from behind that heat shield…
My indy mech has not had time to inspect yet but I suspect it's part of the ABC system as there's a valve block where lines run to.
I had the car up on my home lift, immediately after driving and isolated the noise to this spot:
It's coming from behind that heat shield…
My indy mech has not had time to inspect yet but I suspect it's part of the ABC system as there's a valve block where lines run to.
Thread Starter
Newbie
Joined: Apr 2021
Posts: 4
Likes: 0
SL55 R230
I'm in the midst of troubleshooting what I think is the same noise on my 03 SL55 w 33k mi. It's a faint knocking—a slightly metallic noise coming from behind the seats either under the car or behind the rear bulkhead. I initially thought it was a tick not unlike an exhaust cooling but it's too rounded a sound and mine is also rhythmic (about every 20 secs). I'll hear it for awhile after shutting off the vehicle, maybe up to an hour. I suspect it makes noise while i'm driving or when the car is on, it's just not as apparent with engine and road noise going on.
I had the car up on my home lift, immediately after driving and isolated the noise to this spot:
It's coming from behind that heat shield…
My indy mech has not had time to inspect yet but I suspect it's part of the ABC system as there's a valve block where lines run to.
I had the car up on my home lift, immediately after driving and isolated the noise to this spot:
It's coming from behind that heat shield…
My indy mech has not had time to inspect yet but I suspect it's part of the ABC system as there's a valve block where lines run to.
Junior Member
Joined: Mar 2007
Posts: 34
Likes: 18
Mine is definitely persistent not dynamic. I thought it might be the same as yours because yours is evident after the car is off while no components should be moving. I also thought it was a tick at first but the more I isolated it, realized it wasn't.
If you get a chance, next time you drive and park, pop your head under the car in front of the rear driver's side wheel. It wasn't until I got a lift that I pinpointed the sound. It initially sounded like it was behind the passenger seat. I had an ABC flush not too long ago and everything was in spec but it might be the valve block at the very initially signs of going.
If you get a chance, next time you drive and park, pop your head under the car in front of the rear driver's side wheel. It wasn't until I got a lift that I pinpointed the sound. It initially sounded like it was behind the passenger seat. I had an ABC flush not too long ago and everything was in spec but it might be the valve block at the very initially signs of going.
Thread Starter
Newbie
Joined: Apr 2021
Posts: 4
Likes: 0
SL55 R230
So i tried many things today. I rode about 15 minutes then i stopped and recorded this the noise :
The noise is in reality stronger than what you can hear on the video. The tick can be heard every 6 sec, the more i wait the more it takes time, and stop 15 minutes after turning off the engine. Then i removed the two fuses that i believe are the ones used for the ABC system, no change, then i removed the two fuses of the gearbox, no change too. Next time i will disconnect the auxiliary battery, it be will clear if it's something related to some actuators or not. Abc fluid level is ok, but i don't have dipstick for the oil tranmission. When riding the car, i can hear the little noise when i brake hard or accelerate a bit. I know i have a little leakage coming from the gearbox cover i believe, i think i have to change the seal.
