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2018 Mercedes-AMG C63 — costs that mattered more than fuel economy

CanyonDetailer620Community StarterAug 20, 20262018 Mercedes-AMG C63 SNationwide
2018 Mercedes-AMG C63 S, about 40,500 miles. After owning the car for a while, tires, insurance and service pricing mattered more than the MPG difference I obsessed over before buying. What ownership costs surprised you most?
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21 replies

DailyCollector993Community StarterCommunity StarterAug 20, 2026permalink
I'd want a measurement, not a hunch. If a shop can't duplicate it on the 2018 Mercedes-AMG C63, bring a video plus freeze-frame data, not just a story. Don't erase codes until someone who can help has seen them. Not gospel, but it saved me a headache. I'd rather be boring and correct. Trying not to diagnose from the couch.
BoostMechanicish509Community StarterCommunity StarterAug 20, 2026permalink
If it were in my driveway, if a shop can't duplicate it on the 2018 Mercedes-AMG C63, bring a video plus freeze-frame data, not just a story. Don't erase codes until someone who can help has seen them. Post the numbers (or the code) and people can get more specific. Might be overthinking it, but I'd rather overthink than overspend.
FlatSixSeller714Community StarterCommunity StarterAug 20, 2026permalink
Log the conditions before you spend. Capture voltage while the 2018 Mercedes-AMG C63 is actually failing — after it restarts you've lost the clue. You'll know quickly if you're on the wrong tree. On “amg c63 — costs that mattered more,” that was the fork that mattered for me. This is from a 2018 Mercedes-AMG C63 in Nationwide with 40,500 miles. Did the worksheet show tax yet? If your situation is the opposite, ignore me. I'll poke at it this weekend.
UsedCarDaily840Community StarterCommunity StarterAug 21, 2026permalink
Ask what changed right before it started. Write temp, speed, and in-gear vs coast when the 2018 Mercedes-AMG C63 does it — then decide on parts. You'll know quickly if you're on the wrong tree. Keep sale price, fees, and rate as three different conversations. That's coming from doing this as an owner, not a shop. Not driving it hard until I know more.
DealDetailer461Community StarterCommunity StarterAug 21, 2026permalink
Intermittent stuff lies if you only catch it once. Get a real battery/charging test on the 2018 Mercedes-AMG C63, not just resting voltage, before blaming a module. Save the big job until that test fails. On “amg c63 — costs that mattered more,” that was the fork that mattered for me. Keep sale price, fees, and rate as three different conversations. Climate here is different, so treat that as a local data point. This is the version I'd tell a friend.
WeekendDad157Community StarterCommunity StarterAug 21, 2026permalink
Start with the test that can prove you wrong. Capture voltage while the 2018 Mercedes-AMG C63 is actually failing — after it restarts you've lost the clue. That's the branch I'd chase this week. When does it actually happen? I'm in no rush to be a hero on it.
CanyonDetailer620Community StarterCommunity StarterAug 21, 2026permalink
Tried a second charger / second scan and the story on the 2018 Mercedes-AMG C63 didn't change. If it repeats twice more I'll book time.
CanyonDetailer620Community StarterCommunity StarterAug 21, 2026permalink
Cleared nothing. I want service to see the alert on the 2018 Mercedes-AMG C63 first. Parking it somewhere I can hear it better next time.
SunBeltSellerCommunity StarterCommunity StarterAug 21, 2026permalink
I'd want a measurement, not a hunch. Move a coil or plug on the 2018 Mercedes-AMG C63 if it's cylinder-specific and see whether the code follows. Save the big job until that test fails. Post the numbers (or the code) and people can get more specific. I'd sleep better after that step, even if it finds nothing. I keep a notes app thread for this now.
CanyonMiles540Community StarterCommunity StarterAug 21, 2026permalink
Ask what changed right before it started. A pressure test beats staring at a dry driveway if the 2018 Mercedes-AMG C63 is losing coolant with no puddle. Don't erase codes until someone who can help has seen them. Not gospel, but it saved me a headache. I keep a notes app thread for this now.
BoostMechanicish509Community StarterCommunity StarterAug 21, 2026permalink
This is usually cheaper to test than to guess. If a shop can't duplicate it on the 2018 Mercedes-AMG C63, bring a video plus freeze-frame data, not just a story. You'll know quickly if you're on the wrong tree. This is from a 2018 Mercedes-AMG C63 in Nationwide with 40,500 miles. If you share a photo of the worksheet, easier to sanity-check. This is the version I'd tell a friend.
CleanMechanicish787Community StarterCommunity StarterAug 21, 2026permalink
If it were in my driveway, two 2018 Mercedes-AMG C63s can feel identical and have different causes, so measure before you copy someone else's repair. If the cheap test changes it, stop and reassess. If they can't show the line item, I assume it's hiding. I'll poke at it this weekend.
SunBeltSellerCommunity StarterCommunity StarterAug 21, 2026permalink
Intermittent stuff lies if you only catch it once. Move a coil or plug on the 2018 Mercedes-AMG C63 if it's cylinder-specific and see whether the code follows. Don't erase codes until someone who can help has seen them. On “amg c63 — costs that mattered more,” that was the fork that mattered for me. Happy to compare notes if your setup is different. I keep a notes app thread for this now.
GarageRoadieCommunity StarterCommunity StarterAug 21, 2026permalink
Asking because it changes the advice: Get a real battery/charging test on the 2018 Mercedes-AMG C63, not just resting voltage, before blaming a module. You'll know quickly if you're on the wrong tree. Just my two cents from doing this recently. Trying not to diagnose from the couch.
WeekendDad157Community StarterCommunity StarterAug 23, 2026permalink
Not convinced that's the whole story. Write temp, speed, and in-gear vs coast when the 2018 Mercedes-AMG C63 does it — then decide on parts. Save the big job until that test fails. Have you gotten a second quote in writing? Next check is the cheap one I can do in a driveway.
DealDetailer461Community StarterCommunity StarterAug 23, 2026permalink
I'd push back a little: Two 2018 Mercedes-AMG C63s can feel identical and have different causes, so measure before you copy someone else's repair. If the cheap test changes it, stop and reassess. Keep sale price, fees, and rate as three different conversations. Doing the boring step first on purpose.
CleanMechanicish787Community StarterCommunity StarterAug 21, 2026permalink
Intermittent stuff lies if you only catch it once. Get a real battery/charging test on the 2018 Mercedes-AMG C63, not just resting voltage, before blaming a module. Save the big job until that test fails. On “amg c63 — costs that mattered more,” that was the fork that mattered for me. I'd want that in writing, not as a promise. If this is nothing, great. I want that in data.
WeekendDad157Community StarterCommunity StarterAug 21, 2026permalink
Log the conditions before you spend. Two 2018 Mercedes-AMG C63s can feel identical and have different causes, so measure before you copy someone else's repair. Save the big job until that test fails. On “amg c63 — costs that mattered more,” that was the fork that mattered for me. This is from a 2018 Mercedes-AMG C63 in Nationwide with 40,500 miles. When does it actually happen? Climate here is different, so treat that as a local data point. This is me being the wet blanket on purpose.
CleanMechanicish787Community StarterCommunity StarterAug 22, 2026permalink
Agree — and I'd add this: Swap the cheap/easy piece first on the 2018 Mercedes-AMG C63 and see if the fault moves. You'll know quickly if you're on the wrong tree. Verbal 'we'll take care of it' is not a plan. Parking it somewhere I can hear it better next time.
CleanNomad410Community StarterCommunity StarterAug 21, 2026permalink
Ask what changed right before it started. Swap the cheap/easy piece first on the 2018 Mercedes-AMG C63 and see if the fault moves. Don't erase codes until someone who can help has seen them. If they can't show the line item, I assume it's hiding. Video is ugly but it shows the hesitation.
FlatSixSeller714Community StarterCommunity StarterAug 22, 2026permalink
Start with the test that can prove you wrong. Two 2018 Mercedes-AMG C63s can feel identical and have different causes, so measure before you copy someone else's repair. If the cheap test changes it, stop and reassess. Have you gotten a second quote in writing? If the story changes I'll post the new data.
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