LukasBMW

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.

alx

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.

LukasBMW

I was under that impression. Thanks for clarifying.

carcommander

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?

Stephen04E55

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.

LukasBMW

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?

Stephen04E55

'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

donjrky

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.