SL55 AMG, SL63 AMG, SL65 AMG (R230) 2002 - 2011 (2003 US for SL55 and 2004 for the SL65)

SL55/63/65/R230 AMG: Question on the V12 coil pack problem

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Old Jan 14, 2012 | 01:07 AM
  #1  
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2005 C55 AMG - 2018 340i - 2006 SL55 AMG - Sold
Question on the V12 coil pack problem

In September it was hot (110o) as I live in Arizona.

I had my car parked outside a rental property and started the car 3 times in a row rather quickly (started it, remembered I forgot something, turned the car off, started the car, remembered I forgot something else, turned off the car, started the car for a 3rd time).

After the 3rd start, I felt a shudder and my check engine light came on. I could tell the car was "missing" and I turned it off. I knew right away it was probably the coil packs since they always seem to go bad on these cars.

The dealer confirmed that the coil packs had thrown the code but my warranty would not authorize repair because by the time an inspector came out to look at the car, the check engine light was off and the car was no longer having problems.

Sure enough, the car has run great since the incident. Is this normal? I figured once the coil packs acted up, they would keep acting up. I didn't think it would be possible for them to cause a misfire on one day and then continue to work fine.

Truthfully I'd like to get the car to misfire again so I can have the coil packs replaced under warranty. I don't know mine have ever been changed and I have yet to meet another 2003-2004 V12 owner who has not had his coil packs replaced.
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Old Jan 14, 2012 | 01:16 AM
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alx
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You might have experienced fuel line vapor lock. Your coils might be still good. Usually when they go bad they go bad in a hurry and they stay broken.
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Old Jan 14, 2012 | 03:20 AM
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I was under that impression. Thanks for clarifying.
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Old Jan 15, 2012 | 09:31 PM
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My 06 used to do that and would run rough for a bit. It was the turbo boost sensor. Have you ever changed the plugs?
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Old Jan 16, 2012 | 06:40 AM
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'09 CLK550, '18 AMG GTR, '06 C55 AMG, '25 GLS450, 09 E63
I just replaced the coil pack on the driver's side of my '06 S65. Mine was intermittent as well but finally went out and put the car in "limp" mode. If you know it threw the code and it is in history, get the dealer to pull it and check the rubber insulators to make sure they aren't the culprit. MB is very frugal and would rather not pony up the $1500 for a coil pack so push the issue.
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Old Jan 16, 2012 | 11:56 PM
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The warranty is actually through Fidelity. If it happens again, I will make more noise.

BTW, 10.58@132.46 in a S600? Damn! Anything other then software?
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Old Jan 17, 2012 | 08:34 AM
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'09 CLK550, '18 AMG GTR, '06 C55 AMG, '25 GLS450, 09 E63
'03 S600 mods were Renntech ECU/TCU tune, BMC air filters, Eisenmann rear section exhaust, Mickey Thompson drag radials and 150 shot of N20. Best no N20 was 11.25@123
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Old Jan 17, 2012 | 08:16 PM
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2005 SL-65 2002 M3
I have replaced 2 coil packs, first at 29k 2nd at 49k, both on the driver’s side of my SL65. No help from MB on either. They both were intermittent. Fine for days, then it would throw the check engine light. I'd fuss and get it replaced while warranty is picking up the tab. I assure you it WILL fail.
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