I bought my 2007 SL550 earlier this year and I couldn't stop smiling when I drove it. The problem is every other time I start it I have to take it in for that mysterious parasitic battery drain problem. This morning I got the red battery light and the order to turn off the car. I'm going to dump this thing at a loss and find something more reliable. I guess the moral of the story is never chase your dreams because they can turn into nightmares. Good luck with yours. Out.

 

Are you mad? Did you try taking it to, oh I don't know, a car shop?

 

Of course I did. 3. Money down the drain.

 

Any of those shops use a STAR diagnostic to troubleshoot?

 

No idea. I've researched this problem extensively and my last stop will be the MB dealer to get it ready to sell.

 

Where are you located?

 

Des Moines

 

The MB dealer should have been your first stop for the battery draw. It isn't that difficult to diagnose for someone who knows what they're doing.

 

Not sure what procedure the last mechanics you visited used but here's a video from a reputable YT mechanic that shows how he found the battery drain in a SLK- I'm sure the procedure is very similar for any mercedes

In this case it was the SOS button/Fuse

Give it one more shot......

 

Im kinda with you. Im about 2 months into my SL journey and its been rough. To the tune of about $5k of repairs. Partly real car issues, partly mechanics not knowing what they are doing...
Seems be ok and im having my wife drive it daily, but one more issue, its out. It only 15k miles on it so maybe it just sat too long.

 

I am pretty close to you, sending you a PM.

 

That'll be the final screw.....if you decide to sell it to the dealership.

 

If your car is over 10 years old with that millage you need to treat it like 100,000 miles and start replacing all of the service parts that would have happened in the last 10 -115 years . In other words start at zero. All of them and beyond .

 

That makes sense and i think most if not all of that has been done. Mechanically it seems to be ok. No leaks and i did replace both batteries and the alternator. The main issue was the top, $4k of the $5k i mentioned above. And of that $4k, $3 of it was wasted on a mechanic that didnt know what they were doing.
I think what the orginal poster is missing is a mechanice that really knows these cars and can actually fix them. If i hadnt found this person, im sure i would have sold it by now. And to the orginal poster, i actually found the mechanic through my mercedes dealer. Its who they use to fix the older cars and they nicely just sent me directly to him which has saved me a ton of money so you may want to talk to your dealer to see if they have some type of arangement like that.

 

UPDATE: After two weeks of attempting to extract some sort of response from the dealer I have been vindicated. They have admitted that their response was lacking and this problem was actually caused by them and they failed to fulfill the sales contract by correcting a problem with the car when I bought it. They are not only paying me for the two mechanic bills I incurred but they are sending the car to the local MB dealer to have it fixed. I credit this response to my wife who viciously Yelped them. When the car comes back they may have mostly redeemed themselves.

 

Well there ya go! Lets see the review

 

SL battery issues are often misunderstood by those not familiar with the system. The dual battery setup and the related battery management module and other parts are far from rocket science, but it's a lot more than a standard charging system, it should have gone to MB from the start. Glad you're getting it straightened out.

 

We bought our '19 GLC300 from a local stealership's used car lot, they had promised us IN WRITING that they could/would handle the periodic maintenance (oil changes, tire replacements, etc). When the first servicing was coming due, we scheduled it, 3-4 weeks in advance, PLUS the rear two tires were almost bald, so I told them to order the tires. Then I took it to that particular stealership, they gave me a ride home, and said that they would call me and send me a ride to go pick it up when it was done. THE NEXT MORNING, I called them up to check on our GLC...."we're waiting on parts." At that point, I LOUDLY (my entire neighborhood heard me) reminded them that I had scheduled it weeks ago so that they could have the parts there when I brought it in. My wife and I (BOTH) Yelped the snot out of them, every day, including the day that we picked it up. They had our car for 4 FULL DAYS, before they finally called and picked us up, to go get it. I had also ordered a part from them for my truck on Veteran's Day, before calling to schedule the maintenance. They were constantly telling me "the part had not arrived, yet." When we picked up our GLC, we added that to our grievances with them. Before we got home, the service/parts manager called me to let me know that my part will be at my house the next day via UPS. 2 days later, it showed up. Our '19 GLC300 has NOT been back to that stealership since, not even to pick me up after dropping my truck off for work.

OH, 1 week after the part for my truck arrived, I had time off and installed it on my truck. TWO WEEKS LATER, the stealership's parts department called me to tell me that they found this part, WITH MY NAME ON IT, sitting in their warehouse, package was "received dated" before Thanksgiving. I almost went down there and picked it up, but would be my luck, as soon as I sold it, they would figure out that they gave me two.

 

Glad that you found some resolution to this. Your dealer is probably not going to like the Mercedes service bill, but that's not your problem.

 

Ooo, EVERYBODY loves a happy ending‼️ I’m going and get my keys and hit the Beltway with the top down for a minute in your honor. You picked the right girl sounds like. Seriously though, this forum has made me so very smart about this car. When it does go to my mechanic I’m armed with good knowledge after doing research here. Thanks for sharing your issue.

 

And please do tell in the end what the problem was and what they did to repair it. I also recently bought an '07 SL550. So far so good. I bought it on the basis that it had only 2 previous owners, and that the seller was a mechanic that bought it at dealer auction and brought it to spec for sale. Lots done to it for the sale but with these cars you never know. Every story is a lesson for the next owner.

 

With these cars, it's crucial to have a shop that has techs who know the car. I'm lucky to have near me a shop that's family owned over 30 years and they are honest and they have techs on site who used to work at Benz dealerships. They will do anything a dealership would, other than steal things out of the car, for less money and their guys are as knowledgeable as anyone at a Benz dealer. Plus they warranty every thing they do for a year longer than the Benz dealer would. I also have an indy guy who is a one man shop, I actually know more about these cars than he does but he is great for things like motor mounts. Everything he does is accomplished in less time than the "book" says. Between the two, I am really lucky. You have gotta have a shop locally where tehey can be trusted and hopefully they have someone who knows these cars. There are enough R230's out there that it can't be impossible. Most dealerships are probably okay, but the one near me did things so horrible I'll never bring a car there again. My '07 SL550 is about as trouble-free as I could wish for. I did spend about 5 grand on my SL600 --trans service, brakes flush, coolant hoses all replaced, coilpack rebuilt and several other things, but all that's to be expected. It ain't a celica!

 

Update update and final post.
After 5 weeks with the Mercedes dealership it was determined that some lights come on sporadically. They are doing a wire by wire search. The dealership I bought the car from has agreed to totally refund my purchase price and take the car back. Yes, I'm as shocked as you are now but their policy is "do the right thing" and they apparently live by it.
Bye.

 

ive posted a few similar threads and responses about being done with my SL, but after finding the right mechanic that was able to actually fix the issues, its been flawless. Its a daily driver for my wife and shes put close to 3k trouble free miles on it over the last couple of months. Actually seems to run better now that its driven daily.
So my perception of these things has changed. Actually thinking of buying a second for me...

 

you should post the vin number in case a prospective owner googles the vin and finds this thread at some point in the future.