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Discussion Starter #1
When idling in gear, I hear a lound rumbling noise..... This only occurs with the the transmission engaged (forward or reverse) and stopped or near stop. Move to park or netural and the noise stops..... No problems shifting or when running....... only when idling and not moving. Almost feels like the transmission is trying to move the the truck forward.... Creating a grinding sound.... Sounds and feels like the motor is idling rough, but looking under the hood, it is not the motor...... or the brakes... and it will occurwith or without the brakes applied

Any idea what would casue this? How to fix? Just started yesterday everything was fine till then.

2002, ML320, 70K miles
 

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Discussion Starter #2
Still Having Problem

I'm still having this problem...... does anyone have any ideas on how to determine what is the problem? I need to take to dealer... but hopefully there might be a simple solution I can address myself........

Any insight would be appreciated....... Rumbling noise is very pronounced when idling and in gear. Move to neutral or park....... no issues........ no issues when driving......... Read some of the transmission posts........ do you think I might need to change fluid? or a more serious problem?
 

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2000 W163 ML430 1997 E39 BMW 528i
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277 Posts
When the tranny is in neutral or park, the engine rpm is usually higher by approximately 50-100 rpm. Be absolutely sure that it is not coming from the engine bay area.

If your tranny is grinding like you describe it, it will shift (or not) rough. Pop the hood open and keenly observe where the nosie is originating from.
 

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2005 E500, 2007 ML350, 2007 VW Rabbit
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cal45fan said:
Pop the hood open and keenly observe where the nosie is originating from.
But please dont get yourself caught in a fan.

As the son of a former ML320 owner (I drove the car the last 6 months before we traded it on an '07 ML350), I can say that we had to replace the spark plugs at least twice because the engine was running noticeably rough. The may be your problem.

If you really think it's the tranny, then you should get to a dealer pretty soon. Good luck. :)
 

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1999 E55, 2001 E320, 1990 560 SEC, 2004 ML350, 2001 ML55, 1995 S500, 1998 SL500, 2010 E550 Sport zoo
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Could be a motor mount...

Get a diagnosis... could be a motor mount too, not unheard off..
 

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2002 ML320, 2005 S430 4MATIC RIP, 2010 F150 Crew Cab
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11,305 Posts
MBRob said:
It was the motor mounts......... Thanks
I was reading your thread with interest and already had it pegged as motor mounts. My friend's 300SE done the same thing.
 

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2002 ML 500, 1994 Ford Explorer donated to Doctors without Borders
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I had this problem on another car once and it was a loose exhaust heat shield. Since the car was 13 years old, I just ripped off the shield. It lived happily without it.
 
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