So.... I have owned my 2007 SL550 for about a year and half. going into the purchase I was aware of the TCO of a older vehicle like this one and I was OK with it. I feel comfortable around tools and changing bolt on stuff that I can get to but I am no mechanic. Anyways, several months ago I started experiencing a slow crank and start and a real lurching crank, but would always start. When it would start, it would idle fine and perform well on the road under throttle. I started to get just a clicking no crank every now and then, sounds like a dead battery to me. I replaced the battery and that is when everything went to a soup sandwich. Immediately got a nice fast crank but no start, after 12-15 goes at it, the car would finally start. My service B was due (I am at (93K miles), so I changed the spark plugs, they all looked ok, no fouling. Still fast crank no start. I read around here to look at CPS, so I changed that too, still would take way too many cranks to start. At this point no codes in either OBII or Star. I felt that without anything smoking or on fire and no codes I needed some help, I took it to an independent with very good experience and ratings and he has now had it for 2 weeks, changed Fuel pump and filter, burned up my starter from so many cranks (it was probably on its way out anyways) replaced starter, it fired up but then started the same thing as before. he came across a old bulletin on the ECU being a possible culprit. He physically showed me under the no start condition a light tap on the ECU and boom... start right away. Our discussion was he would pull it, send it out for replace/rebuild to Beckman on the East coast. The shop has been very cool about all this and is covering everything under the original fuel pump charge. Anyone got any input on possible missed items? I have read bout NSS and camshaft sensors. thanks

***UPDATE***
East Coast shop is not able to repair my existing ECU. The hunt is on for a used one that is compatible, does anyone have a list of compatible p/n's? mine is A2731533979, and my understanding is that a used unit will need to be wiped or unmarried and then my shop
will reprogram the unit to work with my car. this is going South in a hurry.......

***UPDATE*** 10/10/2019
Ended up having to take the vehicle to local Benz dealer, $1900 dollars later I got my car back and running, absolute Sh*t show at the dealer. anyhow the following is a cost breakdown for the last 18 months;

• Consumer Battery (rear) $200
• radiator replacement $1100
• Rear tires $500
• oil change $17
• Starter Battery $200
• Front Brakes $300
• Front tires $500
• ECU $1900
• Service B $400 (spark plugs, etc...)
• this does not include the work done for free trying to diagnose the no start condition (Starter, fuel pump, fuel filter, relay)

All this doesn't include the Top Speed exhaust I put on (that sounded absolutely Beastly!) $700 nor the Icarsoft2 for $300 dollars

Bottom line the most amazing car I have ever owned. I knew going into it that maintenance and repairs were a bear but GAWD, I traded it in yesterday for a Lexus, I will try again in 5 years, thank you all for you words and input

OP

OP

 

Does your shop use mb star system? Seems like throwing parts at it otherwise. These cars have a highly engineered management system aboard. Managed system for fuel spark air. They can tell you where the problem (s) lie and how to r and r. Find a DAS system it could save time and potentially $$.

 

A very nice gesture, not charging you anything beyond the fuel pump. If a tap on the ignition key ‘solves’ your problem, it would seem you’ve found the cause of your trouble. I’ve read exactly that story on this forum.
Fwiw: under normal conditions, the starter battery only feeds the starter motor, nothing else. So, an enthusiastically crancking starter says nothing about other electric components like fuel systems, ignition, motor management etc. Or your (much heavier) accessories battery in the trunk...

 

Yes they have Star, but no diagnostics pointing to anything obvious

 

yes, we had the throwing parts at it discussion and I can tell they are a little embarrassed and want the car out of their shop as much as I want it back.

 

Ah..the deeper it gets the more $$$ will change hands, Sorry. Hard to understand how MB star could not discover major ECU problem.. If they need coding feature, they hopefully know what to do.. Keep us posted.

 

The very nature of EIS trouble (I think that’s the topic here) is that it messes up communication within the car. I could see that hick up extend to diagnosis from without the car. My car was misdiagnosed three times before the dealer agreed to exchange EIS, forgoing yet another diagnosis (not without my written consent).

 

Maybe the problem was with firing the primary ignition circuit for the spark plugs, and the engine controller is incapable of detecting a fault. Star Diagnosis won't report engine-related codes that aren't generated in the engine ECU.

 

***UPDATE*** 10/10/2019
Ended up having to take the vehicle to local Benz dealer, $1900 dollars later I got my car back and running, absolute Sh*t show at the dealer. anyhow the following is a cost breakdown for the last 18 months;

• Consumer Battery (rear) $200
• radiator replacement $1100
• Rear tires $500
• oil change $170
• Starter Battery $200
• Front Brakes $300
• Front tires $500
• ECU $1900
• Service B $400 (spark plugs, etc...)
• this does not include the work done for free trying to diagnose the no start condition (Starter, fuel pump, fuel filter, relay)

All this also doesn't include the Top Speed exhaust I put on (that sounded absolutely Beastly!) $700 nor the Icarsoft2 (to help diagnose and clear alarms and warnings) for $300 dollars

Bottom line, this is the most amazing, fun car I have ever driven. I knew going into it that maintenance and repairs were a bear but GAWD, I traded it in yesterday for a Lexus, I will try again in 5 years, thank you all for you words and input

OP

 

Pics of exhaust installed please

 

Other people can mate ECU's, even tuners so I'm not sure why that didn't work out.

Where did you trade in? Mileage?

Edit: also exhaust clip?