Why does the engine sound loud but the car doesn't accelerate when pressing the accelerator?
2 Answers
When the engine sounds loud but the car doesn't accelerate when pressing the accelerator, it may be due to a dirty throttle position sensor or voltage imbalance, or air leakage or blockage in the intake system. Here are the detailed explanations and solutions: Dirty throttle position sensor or voltage imbalance: In this case, it's necessary to check the fuel pressure, cleanliness, and replace the fuel filter. Air leakage or blockage in the intake system: For this situation, you need to inspect the ignition system, cylinder wires, spark plugs, etc.; check cylinder pressure and whether the engine is misfiring; examine if the intake and exhaust pipes are unobstructed (catalytic converter blockage).
That day when I was driving uphill, the engine roared loudly when I stepped on the gas pedal, but the speed barely increased—clearly a drivetrain issue. Clutch slippage is the most common cause, especially in older manual transmission cars where worn clutch plates waste power by converting it into noise. For automatic transmissions, insufficient transmission fluid or torque converter failure can also cause this. Last time I encountered this, replacing the clutch plates fixed it. Additionally, fuel system blockages, like aging fuel lines restricting supply, can make the engine rev hard but deliver weak power output. Never keep driving in this condition—it worsens wear and is dangerous. Get it inspected at a repair shop immediately.
