What causes abnormal noise when accelerating and the car speed not increasing?
3 Answers
The main reasons for abnormal noise when accelerating and the car speed not increasing are as follows: 1. Engine misfire: For example, if the ignition coil of a certain cylinder is damaged, causing the engine to change from 4 cylinders to 3 cylinders, the fuel efficiency of the engine is very low at this time, and the output torque value of the engine is small; 2. Problems with the engine fuel pump: Damage to the engine fuel pump leads to insufficient fuel supply, where the engine speed increases but the fuel injection volume is very low, resulting in very low output power. The accelerator is also known as the 'throttle' or 'gas pedal', and refers to the control device that regulates the engine power (thrust).
As an experienced driver, I often encounter situations where there's abnormal noise when accelerating and the car struggles to gain speed. This could be due to issues with the engine's ignition system, such as worn or dirty spark plugs causing poor ignition, making the engine work hard but without delivering power. It might also be a fuel supply problem—low fuel pump pressure or clogged fuel injectors preventing fuel from entering the combustion chamber, leaving the car powerless. Those abnormal noises, resembling metal friction or a buzzing sound, often indicate mechanical components struggling. Another commonly overlooked cause is a blocked intake or exhaust system: a long-unreplaced air filter restricting oxygen intake, or a clogged catalytic converter trapping exhaust, making the engine groan. These issues need prompt attention to avoid not only wasting fuel but also damaging the engine. I recommend starting with simple self-checks, like replacing the air filter or checking fuses; if that doesn’t help, visit a professional shop for diagnostics and repairs. If this happens on the road, slow down, pull over safely, and avoid pushing the car to prevent accidents.
I think this situation is quite related to the drivetrain. For example, in a manual transmission car, the clutch might be slipping—when you step on the gas, the RPM goes up but the speed doesn't increase, and there might be a hissing or screeching sound. In an automatic transmission, it could be due to old transmission fluid or a faulty valve body, causing rough shifting and dragging performance. I had this issue with an old car I drove last time—it turned out the fuel filter was clogged, leading to poor fuel supply, and the ignition coils were aging, causing misfires. When checking, first look at the dashboard warning lights, then listen to where the abnormal noise is coming from—the front compartment or the chassis—to make a preliminary judgment. You can handle simple tasks yourself, like changing the engine oil or air filter, but for more complex issues, you'll need to use a diagnostic tool to read the trouble codes. Additionally, tire slippage or low tire pressure can also cause trouble—though they won't produce loud noises, they affect traction. Remember to maintain your car regularly—I check the spark plugs and fuel system every six months to avoid many problems. Safety first—if the noise worsens, stop driving and take it to a professional mechanic for repairs.
