Humming sound when starting accelerate after a long period of no use
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2012 W166 ML350
Humming sound when starting accelerate after a long period of no use
2012 ML350 65K. I had this symptom twice. The first time was after the vehicle rested about 5 weeks. It started no problem and I drove out of the garage. When I got to the town road and trying to accelerate to 30mph the vehicle hums loudly and the rpm is about 2k. I drove about 3 minutes and then stopped and couldn't find anything wrong. So I started again and got on highway. and this time it didn't go over 45mph with loud humming sounds. I then got off the highway and drove on town road for about 10 minutes at 30mph and the symptom disappeared.
The 2nd time is about 4 weeks after the 1st occurrence and the vehicle rested about two weeks. again the first time I drove it, it hums when I tried to drive at 30mph on town road, but the symptom is lighter than the 1st one. After I drove on town road for about 10 minutes, it got normal.
I wonder what could cause this. Note that this was in January in MN.
The 2nd time is about 4 weeks after the 1st occurrence and the vehicle rested about two weeks. again the first time I drove it, it hums when I tried to drive at 30mph on town road, but the symptom is lighter than the 1st one. After I drove on town road for about 10 minutes, it got normal.
I wonder what could cause this. Note that this was in January in MN.
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W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
It's hard to tell without actually hearing the sound, but it could simply be your tires which will deform a little from the weight of vehicle sitting on the same spot for an extended period of time. The rubber hardens over time, especially when it's cold, and the tires can take 15-20 minutes or so of normal flexing (rotation) for them to warm up and return back to being round. It happens on all the cars I have sitting in storage over the winter months, even with the tires inflated to 50 psi during storage.
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2012 W166 ML350
This is a very interesting theory. I have been living in MN for more than 20 years and we always left cars undriven for couple weeks every year and never had this issue. next time, when this happens again, I hope it will not, I will record the sound and post here. Thanks for responding!
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MBWorld Fanatic!
Joined: Jan 2013
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From: The Great White North
W204 C63 Coupe, W166 ML350 BlueTEC, 928GT, Taycan GTS Sport Turismo, C5 Z06 & IS300 race cars
Was just re-reading the thread and saw your earlier reply... if you couldn't accelerate past a certain speed then it's definitely not the tires being flat-spotted from sitting. In that case I'd be looking at the torque converter of possibly the transfer case. If you mean that you couldn't accelerate past XX mph without the humming noise - but could with the car humming - then it certainly might be the tires flat spotting due to the car sitting on them.
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From: Boston, MA
'14 ML350, '13 C220 CDI, '07 C280, '98 ML320
I am thinking the issue is with transmission/torque converter/transfer case. Just need to eliminate one by one.
I wonder if there are any error codes are logged (related to the above components).
I wonder if there are any error codes are logged (related to the above components).
Last edited by pcy; Mar 2, 2018 at 05:10 PM.
MBWorld Fanatic!
Joined: Mar 2004
Posts: 1,175
Likes: 24
From: Boston, MA
'14 ML350, '13 C220 CDI, '07 C280, '98 ML320
If you have access to MB diagnostics code reader (or iCarsoft), check for codes in the transmission.
