The problem of the car humming when the cold car starts to a certain speed range can be caused by a number of reasons. Here are some possible causes and workarounds:
1.Engine Problems: Some parts of the engine, such as valves, pistons, crankshafts, etc., may have problems that cause a humming sound at a specific rpm. If you suspect an engine problem, it is recommended to go to a professional repair shop for inspection and repair as soon as possible.
2.Driveline issues: Some parts in the drivetrain, such as driveshafts, bearings, gears, etc., may have problems that cause a buzzing sound. It is necessary to check whether the drivetrain is working properly and replace the damaged parts.
3.Tire problems: There may be abnormal wear or damage to the tread or hub of the tire, resulting in a buzzing sound. The tires need to be checked to see if they are in good condition and can be replaced if necessary.
4.Vehicle suspension issues: Some parts in the vehicle's suspension system, such as shock absorbers, suspension arms, bumpers, etc., can have problems that cause a buzzing sound. It is necessary to check that the suspension system is working properly and to replace the damaged parts.
The above are just some possible causes and solutions, and the specific situation needs to be checked and judged by professional maintenance personnel. If your vehicle has a similar problem, it is recommended to go to a professional repair shop for inspection and repair as soon as possible, so as not to affect the normal use and safety of the vehicle.