Motor cycling sound?
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Joined: Nov 2007
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2007 ML 320 CDI, 1999 C43 AMG
Motor cycling sound?
I am trying to identify the source of a new sound. When I turn the key to the on position I can here what sounds like an electric motor cycling. Similar to the electric lock actuator, but it continues as long as the key is on.
I have tracked the sound to the trunk on the passenger side. When I pull back the trunk liner I can see a dark foam block covering something. That something is making the noise and I'd like to identify what that is before I pull it all apart. Does anyone have an idea what is behind that foam block?
I have tracked the sound to the trunk on the passenger side. When I pull back the trunk liner I can see a dark foam block covering something. That something is making the noise and I'd like to identify what that is before I pull it all apart. Does anyone have an idea what is behind that foam block?
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12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG + Ultima Can-Am sold)
Probably the air pressure pump for the locks and seats. Are you sure the fuel pump hasn't become noisy? It does work when the ignition is on
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1999 C43, 2008 P30 E63, 2014 SQ5, 2024 Model Y Performance
The air pump for the locks and seats is on the passenger side behind the foam block.
From what you are describing it sounds like you have a leak in one of the air lines which causes the pump to continue to cycle.
From what you are describing it sounds like you have a leak in one of the air lines which causes the pump to continue to cycle.
Thread Starter
Junior Member
Joined: Nov 2007
Posts: 26
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2007 ML 320 CDI, 1999 C43 AMG
Guys thanks for the information. I didn't realize the locks were air actuated, guess you learn something new every day. Sounds like I'm going to have fun tracking down an air leak. Any advice on how to track this thing down?
Thanks for the help
Mike
Thanks for the help
Mike
Thread Starter
Junior Member
Joined: Nov 2007
Posts: 26
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2007 ML 320 CDI, 1999 C43 AMG
So after a bit of fiddling around with switches I have found the culprit. The passenger side thigh bolster is leaking. The good news is I can leave it deflated and the pump doesn't cycle.
Thanks for the help!
Thanks for the help!
