SL/R230: Normal noises ?
Thread Starter
Senior Member
Joined: Feb 2018
Posts: 258
Likes: 34
From: Gluckstadt, MS
2003 R230
Normal noises ?
When getting into my 03 sl500 I can hear several noises, besides my heart racing with anticipation, what are normal? After the windows close I can hear what might be a fan from in the dash near the radio. I also can hear some coming from the trunk I think it is the PSE pump that thumps 3 times and then a different thump from something else back there. Checked and no bodies in the trunk, could is be the hydraulic pump pressurizing?
When I insert the key I can hear others before starting the car. What is normal and what is powering up?
When I insert the key I can hear others before starting the car. What is normal and what is powering up?
MBworld Guru
Joined: Dec 2009
Posts: 10,782
Likes: 1,011
NO LONGER ACTIVE
Many of the systems in your car will "wake up" when there is activity on the CAN bus. Just opening the door will wake some things up. There is a fan in the overhead control panel that draws air across the humidity sensor, so you might hear that. The COMAND unit has an internal fan that you may hear spin up. The PSE pump will run and pressurize its devices, and you may also hear the fuel pump pressurize. Also, you may hear a definite pump motor sound under the hood, which is the SBC system charging the brake fluid pressure. All of this is normal.
Thread Starter
Senior Member
Joined: Feb 2018
Posts: 258
Likes: 34
From: Gluckstadt, MS
2003 R230
Many of the systems in your car will "wake up" when there is activity on the CAN bus. Just opening the door will wake some things up. There is a fan in the overhead control panel that draws air across the humidity sensor, so you might hear that. The COMAND unit has an internal fan that you may hear spin up. The PSE pump will run and pressurize its devices, and you may also hear the fuel pump pressurize. Also, you may hear a definite pump motor sound under the hood, which is the SBC system charging the brake fluid pressure. All of this is normal.
