spartacus2002

2010 E550 4matic with 44K miles. Bought it a year ago with 40K miles, have had zero problems.

About a month ago, it started having a slight issue when I turn the key to start it cold. Starter turns over once, pauses a half-second, then turns again and the engine fires up just fine.

Not sure if it is battery, starter, or other. Does the 2010 E550 4Matic flash a warning on the dashboard if the primary battery is dying? I plan to take this to an MB mechanic but wanted to check with you guys first.

Location is St. Pete, FL, where it doesn't get too cold. Lows the past month have been 55 degrees F. No other issues with the vehicle, and it has started/run perfectly fine before this.

belarus27

Battery or a starter(common issue with 550s)
there are threads about this exactly the same issue , id ppst a link but itll take some time to find them on the phone. So just search for it. Good luck

KEY08

Yeah, start with the battery. Heat is your problem not cold. The battery could be going and solves this slow crank issue for many. For others, it is the starter,

thefisch

OP, if it is the original battery it's probably time for a change. You could hook up a donor battery or another car to jump to see if that starts faster. If it's not the original battery, best to pull the battery and get it load tested.

Airmousam

I had my battery and starter replaced under CPO...Had the exact same issue. They replaced the battery as good will stating the starter had stressed the battery

Magicman09

Defiantly try to test your battery before having the starter replaced. However, I agree, it sounds like the starter may end up being the real problem..