2023 Mercedes-AMG C43 — coolant is old by age but mileage is low

Log the conditions before you spend. Write temp, speed, and in-gear vs coast when the 2023 Mercedes-AMG C43 does it — then decide on parts. Save the big job until that test fails. On “amg c43 — coolant is old by,” that was the fork that mattered for me. Learned this the expensive way on a previous car. If this is nothing, great. I want that in data.

Start with the test that can prove you wrong. Two 2023 Mercedes-AMG C43s can feel identical and have different causes, so measure before you copy someone else's repair. Save the big job until that test fails. I'd want that in writing, not as a promise. Trying not to diagnose from the couch.

If it were in my driveway, write temp, speed, and in-gear vs coast when the 2023 Mercedes-AMG C43 does it — then decide on parts. Save the big job until that test fails. I'd want a dollar figure or a measured spec, not 'should be fine.' Not trying to scare you — just skip the expensive first guess. I'd rather pay for diagnosis than a second guess-repair.