Ive searched this subject and have yet to come up with an answer.When my 2010 E350 is sitting in the garage,i hear a sound coming from the engine bay that ressembles a servo motor turning on and off abour every 5 minutes.It lasts about 3 seconds.Any ideas? Thanks in advance

These cars love to make noise when sitting, but not every 5 minutes. I would have a pro look into that one.

If it's happening that often it shouldn't be too hard to pop the hood and listen to pinpoint the source. I'm surprised your battery hasn't died.

The car has fans that will run for up to 5 minutes after its turned off for cooling. That is what the noise is

So, OP what is the noise?

Every 5 min? Did you leave a hooker in the trunk??