Starter replacement on 2011 E550 Coupe
It's been a while since i've posted, but I was noticing an issue with my car for the past few months where it would take quite a while to start up. Originally, I had thought it was the battery or maybe the alternator, but just last week I had tried to jump start my car and nothing. All I would hear when trying to start was a CLICK. I did notice that the battery had a voltage reading (via multimeter and on board vehicle diagnostic) of ~11.7 V. From what I gather, that is a bit low, though all the interior lights and dash work properly, it's just that the engine wont start. For good measure though, I tried to start the car with a new battery (voltage was ~12.2V), but still the same symptoms; lights and dash turn on and I only hear a CLICK from the engine bay.
From the above, I think I've narrowed it down to the starter and NOT the alternator or battery (though please let me know if I might be wrong or there are other tests I can perform to narrow down the culprit), and I was wondering if anyone might know the actual part number of the OEM starter that needs to be replaced. I'm looking to get it from RockAuto (or maybe there are other better places to get it from?)
Any help would be much appreciated
Thanks!




For the starter itself, i'd do what Chevota said before swapping in a new starter, check all electrical connections, starter relay ( if it has one ), any related fuses and make sure all connections are bright metal.
Let us know you get on with it....
When you try to crank and get said click, do the dash lights dim at all? It's just an indicator that the starter is trying and drawing a ton of power. Or the battery can't supply the power it needs, but with a new batt I doubt that's the case.
Assuming the lights stay bright, then the power is not getting to the starter. It could be a bad connection, like corrosion on either Pos or Neg, or the solenoid on the starter is worn or broke, or the brushes are warm/broke. Sometimes the windings in the starter can fail but pretty rare imo. Whatever the case, the power is not getting to the windings.
On my car, with a new batt and apparently good starter, cranking the engine sucks a lot of juice and voltage drops below 11. I measure at the ECU which is no doubt lower than at the battery, but fyi.
When you say takes a while to start, does that mean cranking and cranking before it lites off, or click click click over and over until it finally cranks and starts normally? The latter is classic solenoid failure. A redneck fix for that is smack the solenoid, or whole starter, hard with a hammer or steel rod. Smacking bad electronics/electrical things works surprisingly well at resurrecting them, if only for a little while. It's also a big clue when trying to figure out wth is wrong. If that brings it back to life then you can repair or replace the solenoid, or replace the whole starter. I don't replace the starter unless I have no choice because new are usually stupid expensive and rebuilt almost always, somehow, fail very quickly. I don't know how they can screw up a starter rebuild but they're masters at it. The solenoid usually looks like a short/fat cylinder mounted on the starter, it's the part with the wires going to it and you almost always have to remove the starter to replace it.
I've never even seen my starter, so I can't give you any specific advice about it. I assume it's down in the usual spot but despite poking around under there for other reasons, but don't recall seeing it. So the aforementioned troubleshooting and tips is generic starter info, but I can't imagine this is any different. And with all starters, the solenoid is the #1 failure point, which may or may not click, but the bottom line is it won't pass the power to the motor so no cranking. Unless maybe you smack it good
I had one car with a bad solenoid that I dreaded pulling the starter because it was such a pita to get to, and I hated the car (Saturn). So if it wouldn't crank I carried a long heavy steel bar that could pop the hood and reach deep down in there to smack it. Eventually I bought a new solenoid, which was like $20, and swapped it out. It had a sealed solenoid, as most today are, but some are not and you can fix 'em. There was once a place near me that, long ago, that rebuilt them and actually did a good job, but the point is they would sell you just the parts, which was super cool. Good luck finding a place like that today. I'm pretty sure all rebuilds today are done outside the US, with whatever secret ingredient that makes them fail quickly. So when you see a rebuilt starter with a lifetime warranty, like all the local chain autoparts do, don't do it! Same with alternators, which also have that secret ingredient. Probably TMI for you, but better than too little 
Thanks again for the detailed reply
Thanks again for the detailed reply

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I agree though with making sure all electrical connections to the starter are renewed to bright metal before the OP invests in a starter. RockAuto or FCPEuro may have the correct starter..Konigstiger can supply the correct p/n to check. My preference would be FCPEuro due to the warranty on everything they supply.
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Thanks again for the detailed reply

And did you go OEM or Aftermarket?




