TransmissionDiagnostic helpCommunity Starter

2018 BMW 340i — humming rises with road speed, not engine RPM

NoMarkupHaulerCommunity StarterJun 14, 20262018 BMW 340i xDriveOrlando

2018 BMW 340i xDrive, about 119,000 miles. There is a low hum that rises with road speed regardless of engine RPM.

5 replies

HighwayLearnerCommunity StarterCommunity StarterJun 14, 2026permalink

If it were mine, measure it if you can. Two cars can feel identical and have different causes.

SunBeltHunter540Community StarterCommunity StarterJun 14, 2026permalink

I would not stop there. measure it if you can. Two cars can feel identical and have different causes.

TireGarageCommunity StarterCommunity StarterJun 14, 2026permalink

One thing that mattered for me: if it is cylinder-specific on the 2018 BMW 340i, move a coil or plug and see whether the code follows.

RoadTripMechanicish788Community StarterCommunity StarterJun 14, 2026permalink

Before you spend money, if it is cylinder-specific on the 2018 BMW 340i, move a coil or plug and see whether the code follows.

TireGarageCommunity StarterCommunity StarterJun 15, 2026permalink

Fair, but capture when the 2018 BMW 340i does it — temp, speed, and whether it is in gear — before replacing parts.

Similar discussions

TransmissionDiagnostic helpCommunity Starter

2019 Audi S4 — delayed engagement into Drive when cold — anyone dealt with this recently?

After sitting overnight, shifting from Park to Drive can take a second or two before the vehicle actually engages. Once warm it behaves normally. Would you sta…

TowTunerCommunity StarterSep 4, 20262019 Audi S4 Premium PlusLong Island6 replies0 helpful

Diagnostics & Mystery ProblemsQuestionCommunity Starter

2021 BMW X5 — metallic rattle for a few seconds after cold start

2021 BMW X5 xDrive40i, about 75,500 miles. There is a short metallic rattle after the first cold start of the day, then it disappears once the engine settles.…

CamberTraveler327Community StarterSep 4, 20262021 BMW X5 xDrive40iCleveland2 replies0 helpful

TransmissionDiscussionCommunity Starter

Question: Delayed engagement into Drive when cold

On cold mornings, shifting from Park to Drive takes a second or two before the car actually engages. Once warm it's instant and shifts fine. Fluid level/condit…

PixelRoadieCommunity StarterSep 4, 20262025 BMW M3 Competition xDriveSacramento4 replies0 helpful

TransmissionOwner reportCommunity Starter

2021 Chevrolet Silverado 1500 LTZ 6.2 — need advice: Silverado light-throttle shudder: engine or transmission?

At steady speed with light throttle I get a vibration that feels almost like driving over fine rumble strips. It disappears if I accelerate. What's the cleanes…

WrenchWeekend96Community StarterSep 4, 20262021 Chevrolet Silverado 1500 LTZ 6.2Salt Lake City3 replies0 helpful

TransmissionQuestionCommunity Starter

Delayed engagement into Drive when cold

On cold mornings, shifting from Park to Drive takes a second or two before the car actually engages. Once warm it's instant and shifts fine. Fluid level/condit…

HybridPilot80Community StarterSep 4, 20262023 Audi S5 SportbackMichigan13 replies0 helpful