What Causes a Manual Transmission Car to Make a Chainsaw-Like Sound When Accelerating?

[SkylarLee]

Manual transmission cars making a chainsaw-like sound when accelerating could be due to engine knocking, insufficient engine oil, low oil pressure, or friction between the valves and guides as well as hydraulic lifters. Causes of Engine Knocking: The main cause of engine knocking is carbon buildup on the piston crown. This carbon forms a highly intense hot spot, causing the air-fuel mixture in the combustion chamber to self-ignite prematurely before the ignition stroke. Introduction to the Accelerator Pedal: The accelerator pedal, also known as the throttle pedal, is part of the car's fuel supply system. By controlling the amount of pedal depression, it regulates the throttle valve opening, air intake, and the computer-controlled fuel injection, thereby controlling the engine's speed.

[ValentinaFitz]

That manual transmission car's throttle sounds like a chainsaw, I encountered it once last year. My old pickup truck would buzz when driven, just like a chainsaw cutting wood, which was quite scary. Later, I tried to find out the cause: the most common one is an exhaust leak—check for cracks or rust at the joints or pipes, as leaks can produce that high-pitched sound. It could also be an issue with the engine's intake system, like a clogged air filter or excessive valve clearance, which can cause strange noises at high RPMs. The belt is also a suspect—if the drive belt is loose or worn and broken, friction when the engine runs can create noise. I suggest starting with the simple checks: open the hood and listen for the source of the sound, but be careful not to burn your hands. If you've ruled out the filter and belt, it might be a worn hydraulic pump or bearing—don't delay at this point, head to the repair shop quickly to avoid damaging the engine's core components. These checks are quite important and can save you from bigger troubles down the line.

[StJack]

I remember driving manual transmission cars for twenty years, encountering similar issues several times. The chainsaw-like noise when stepping on the gas is too harsh, driving on the highway feels like running a big motor. Once, it was my van's exhaust system bolts loosening, causing a buzzing sound from gas leakage, which was fixed by tightening them. Another time, an old truck's aging and broken drive belt made a chainsaw-like noise from friction during high-speed rotation. Also, a dirty or damaged mass airflow sensor can cause poor air intake, making the engine complain due to insufficient air. I suggest everyone regularly check the undercarriage exhaust pipes and belts, especially areas prone to rust in the rainy season. Wear gloves when doing DIY repairs to avoid engine oil dirtying your hands. Addressing small issues promptly can prevent increased fuel consumption or even major engine problems over time. Safety comes first when driving; pull over to investigate any strange noises instead of pushing through.

[SanHenry]

I dread this kind of abnormal noise the most when driving. A chainsaw-like sound when stepping on the accelerator is usually an engine or exhaust issue. It could be a cracked exhaust manifold leaking gas, producing sharp noises when high-speed gases escape. Alternatively, damaged valve components may cause restricted airflow, amplifying the sound. Slipping belts can also create friction-related abnormal noises. Ignoring these minor issues can escalate risks: for instance, exhaust leaks may release harmful gases, endangering health; prolonged valve problems can drastically reduce engine efficiency or even lead to breakdowns. It's advisable to seek professional inspection immediately rather than attempting DIY fixes to save money. For prevention, clean or replace belts during maintenance and ensure no loose components exist. Safety first—slow down and seek help upon hearing unusual sounds.