What Causes the Puttering Sound in a Car Engine?
3 Answers
The causes of a puttering sound in a car engine are: 1. Engine misfire, where the exhaust gas flow shows obvious intermittency accompanied by severe shaking of the exhaust pipe; 2. Engine carbon buildup and clogged filters leading to an overly rich air-fuel mixture; 3. During cold starts, the engine's lubrication is less effective as the oil has poor fluidity and is more viscous, resulting in a puttering sound, which is a normal phenomenon. Engine maintenance methods include: 1. Using high-quality engine oil; 2. Using qualified coolant; 3. Regularly cleaning radiator scale; 4. Periodically removing carbon deposits from the car; 5. Timely replacement of the car's air filter, oil filter, and fuel filter.
The car has been running for twenty years, and the engine has been making a sputtering noise quite a few times. This is usually related to the ignition system, such as excessive carbon buildup on the spark plugs causing leakage and misfiring, which leads to the sputtering sound; or aging ignition coils causing unstable current, resulting in incomplete combustion in the cylinders. Fuel system issues like clogged fuel injectors causing insufficient fuel supply or a faulty fuel pump with low pressure can also produce similar symptoms. Air intake system leaks, such as a loose intake pipe connection, can cause uneven air intake and lead to the noise. Even a small hole in the exhaust system can mimic this sound. If left unrepaired, the car may start shaking more and more, and in severe cases, it could stall or break down dangerously. I start checking from the simpler parts, like inspecting the spark plug electrodes for blackening and replacing them if necessary, then checking the air filter and pipe seals. Regular maintenance can help reduce the occurrence of such problems.
Last time when chatting while driving, my friend mentioned his car was making a chugging sound, which was quite annoying. The main reasons could be that the spark plugs were worn out and not replaced, causing intermittent ignition and making the engine knock; or the fuel pump wasn't delivering enough fuel, with a clogged fuel line leading to an imbalanced air-fuel ratio, triggering the sound. If the sealant at the intake cracks and leaks air, fluctuating oxygen levels can worsen the chugging. A rusted-through hole in the exhaust system can also mimic this sound. I advised not to ignore it, suggesting to pay attention to sound changes during daily driving and to visit a repair shop for a computer diagnosis if noticed. For prevention, regularly change the engine oil and air filter, and fix any issues as soon as they appear to avoid damaging other components, saving both money and hassle.
