Slow rough crank
06-23-2024, 11:08 PM
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2012 c63 AMG
Slow rough crank
Started having a starting issue a couple weeks back all of a sudden. Would go to crank after it had sat all night or for at least 6 hours or so and it would turnover multiple times until finally it would initiate a rough slow start. Made a post not long ago without any videos. (More info below)
(Mercedes 2012 C63 AMG coupe base model, which for any other Benz owners, enthusiasts or works on them, it has an M156) First thing I did was test the battery which was good, then tested the alternator which didn’t seem to be charging and had around 100k miles on it as it was the stock one that was manufactured with the car so I decided to buy a new one and replace it, had some other coolant/ thermostat parts break on me while changing it out so had to deal with those issues but got the new alternator in and not sure if it really made a difference yet or not. These videos are only after sitting for a couple to a few hours but it’s worse whenever it’s been more. (Except I did notice after replacing the alternator and not having start/drive it for 5 days it started quicker than usual) Made a post not too long about my issue without the videos included and have done a little research and asked around and most have mentioned new sparks and coil kit or possibly bad MAC sensors. I get sparks being potential cause but it’s only an issue on startup, after it’s running it runs completely fine, no rough idling or poor performance and bad fuel economy so wasn’t sure if thats because it hasn’t gotten to that point yet or are the sparks something that should be checked for last?
(Mercedes 2012 C63 AMG coupe base model, which for any other Benz owners, enthusiasts or works on them, it has an M156) First thing I did was test the battery which was good, then tested the alternator which didn’t seem to be charging and had around 100k miles on it as it was the stock one that was manufactured with the car so I decided to buy a new one and replace it, had some other coolant/ thermostat parts break on me while changing it out so had to deal with those issues but got the new alternator in and not sure if it really made a difference yet or not. These videos are only after sitting for a couple to a few hours but it’s worse whenever it’s been more. (Except I did notice after replacing the alternator and not having start/drive it for 5 days it started quicker than usual) Made a post not too long about my issue without the videos included and have done a little research and asked around and most have mentioned new sparks and coil kit or possibly bad MAC sensors. I get sparks being potential cause but it’s only an issue on startup, after it’s running it runs completely fine, no rough idling or poor performance and bad fuel economy so wasn’t sure if thats because it hasn’t gotten to that point yet or are the sparks something that should be checked for last?
