My battery died in a month or two when I started observing a similar problem, although my case can be irrelevant.

Kalt, your post may have helped me piece all of the problems together. I originally thought I had some kind of electrical "gremlin" that was killing my battery. I'm actually on my third battery. I had one replaced under warranty and later splurged and went for an Interstate AGM and a CTEK. My indie checked the alternator/charging system and it was good. Between the dealer and indie, I've had this issue looked at over 6 times in the past year. I was almost about to throw in the towel and pick up a "toy" from Ingolstadt when Belarus told me his starter story.

I bought a Bosch remanufactured starter and the difference is like night and day. For one, it starts instantly...hadn't seen that in over a year. Two, I was charging my battery daily. If I skipped a day or two, it would take two days to charge it to capacity. The battery seems to be less discharged at the end of the day.

I'm only on day 2, but based on what I've seen so far, replacing the starter seems to have helped my situation considerably.

great news , pretty positive your problem is solved. 👍

4shizzle,

Can you give an update on your starting problems? Has replacing the starter fixed things?

thanks,

Peter

So it has been exactly two weeks since I had the remanufactured starter installed. Based on my experience so far, I would have to say that ALL of my issues have been resolved. No more bog or long cranks while starting my car. It just like the day I bought it (CPO 5k miles). So for everyone out there who is experiencing similar issues, you need to strongly consider getting your starter looked at. If you plan on purchasing a starter on your own, please be advised that the RWD car has a different starter than the 4-matic. I took Belarus' advice (thanks!!!) and purchased on eBay. For whatever reason, there were lots of new Bosch 4-matic starters available, but I only found remanufactured starters for my RWD car. I wound up paying for an hour of labor at my Indy. If anyone has questions feel free to post or PM me.

Good to hear!

Thank you very much for your posts on this. I also drive a 2010 E550 and it is very good info that you provided. I have experienced a long crank only twice that I know of. One of them was probably 4 seconds long while the other was probably 3 or so. My car normally starts very easily with about 1 second crank and did this last week after the car sat three weeks at the airport while I was on a trip.


If I start having starting issues i will look into the starter first unless the dealer wants to replace the battery for free first.


Thank you very much indeed!

Hot Start of my SL500, less than 11,000 miles on the clock, has been a problem for 6 months. The engine turns over very strongly with no hesitation, so nothing wrong with the starter or battery. The time between initiating the start and engine firing is 1-6 seconds for hot start and 0-1 seconds for cold start, which is always perfect. No error codes and dealership cannot find any problem with the fuels system pressure or the ignition system. My theory is that the hot engine causes the petrol vapor pressure to rise in the injection piping forcing the fuel back down the pipes. When stone cold the vapor pressure collapse and the fuel comes back up to the injectors or near to them. However when still hot i.e. after 10 minutes to 3 hours, there is a large vapor lock that requires a long series of injection cycles to clear. Then the cylinders get petrol and the engine fires, if one bank of cylinders stayed hotter than the other and in consequence had a longer vapor lock then the engine may run for an instant quite roughly until fuel reaches that bank. Normally as soon as the engine starts, even after a 6 second crank it runs perfectly. The car runs perfectly all the time once started and so I think there can be nothing wrong with any of the systems. I bought the car after it had been standing for 4 years in an underground garage; it had averaging lass than 200 miles per year for a number of years. I suspect the fuel in the system was very old and that this has caused a problem.
So does anyone know where there is a none return valve or some other device that may allow the fuel to push back from the injectors and which may have been damaged by fuel standing for so long?

Finally replaced starter
 

Finally got around to changing out the starter yesterday. Not too bad a job; a couple of cables and two bolts - the upper of which is tricky to get to but if you've a good set of sockets and universal joint you'll get it done.

As others have reported, night and day difference in starting, new starter really spins the motor over.

Thanks to the group for helping diagnose this...

Peter

you changed it yourself?? real good job!!!:eek:

The answer to the hot start problem, long engagement of starter, was the fuel pump. The pump must have a none return valve incorporated that holds the petrol at the injectors. This valve had failed allowing the fuel to be pushed back down the pipework when the car engine was hot. The fix, under warrantee, was a new fuel pump though an enterprising person may have been able to fix the none return valve. The solution was not a crank shaft position sensor (CPS) or a starter motor or the starter battery although the CPS was my first candidate.

So I'm experiencing what i thought it was long cranks...2-3 seconds. This happens around 90% of the time on a cold start. I know some of you said 4-6 seconds which is really long!! I will def bring this up to my SA on my next service visit in like 2 months or so.

You changed yourself? Any "gotchas" to watch out for? I have no problem doing this on my own and I am having the same issues as everyone else is describing.