How to Determine if the Engine Has Carbon Deposits?
3 Answers
Methods to determine if the engine has carbon deposits: 1. Check the fuel consumption rate; if it continues to rise, it indicates that carbon deposits have formed on the engine; 2. Based on the mileage, the higher the car's mileage, the more carbon deposits will accumulate; 3. Switch to a higher-octane gasoline; if there is an improvement in power, it indicates that the engine has significant carbon deposits. Carbon deposits refer to the tar-like substances formed when fuel and oil vapor that enters the combustion chamber cannot be completely burned. These substances accumulate on components such as intake and exhaust valves, spark plugs, fuel injectors, and piston tops. Under the repeated high-temperature conditions of the engine, they form carbon-like deposits similar to coal.
To determine if the engine has carbon deposits, I usually pay attention to some small signals while driving. For example, the car feels much slower to accelerate than before, and the response when stepping on the gas is sluggish, as if dragging a heavy rock. Fuel consumption has also noticeably increased—previously, a full tank could last 500 kilometers, but now it might only go around 450, making the fuel tank feel like a bottomless pit. This is especially obvious during cold starts, with the engine making a buzzing sound or shaking violently, like an old ox panting. Additionally, the exhaust emissions smell stronger, not the usual gasoline odor, but with a sour, pungent edge. During routine maintenance, I use an OBD scanner to read the fault codes. If it shows issues like poor air intake or combustion problems, it’s almost certainly due to carbon buildup. Of course, these minor issues shouldn’t be ignored—it’s safer to take the car to the shop and have them inspect it thoroughly.
When driving my daily commuter car, the most annoying issues are unstable idling and difficulty starting. It should roar to life with just a turn of the key, but lately it takes several attempts, especially in cold weather. During acceleration, it feels like it's choking, with power not coming through smoothly, making overtaking a nerve-wracking experience. The fuel consumption has skyrocketed absurdly, adding several hundred yuan to my monthly gas expenses, which is heartbreaking. Check the ignition coil or spark plugs; if there's heavy carbon buildup, they'll appear blackened or have deposits. You can also use a borescope to peek inside the cylinders—carbon deposits look like a layer of black crust. While these simple methods are handy, I personally find them not precise enough. It's best to have a professional mechanic confirm with a compression test. Don't push your luck—safety comes first when driving.
