Is Combustion Chamber Cleaning Necessary?

[AngelinaMarie]

Combustion chamber cleaning is necessary. After prolonged vehicle operation, carbon deposits accumulate in the intake tract, valves, and combustion chamber. These deposits absorb fuel when the engine is cold and release it when hot, leading to difficulties in cold starts, increased fuel consumption when warm, and degraded engine performance. This results in symptoms such as rough idling, poor acceleration, higher fuel consumption, and excessive exhaust emissions. In such cases, cleaning the combustion chamber carbon deposits becomes essential. Currently, there are several methods for cleaning combustion chamber carbon deposits: Drip Cleaning: A bottle-shaped tool is suspended above the engine, filled with a cleaning agent, which is then fed into the engine through a tube to remove carbon deposits. Engine Disassembly Cleaning: The entire engine is dismantled, and cleaning agents or ultrasonic methods are used to thoroughly remove carbon deposits from all components.

[OMia]

I've been driving a taxi for twenty years, and I believe this depends on the car's condition. If an old car frequently crawls at low speeds, struggles when accelerating, and emits black smoke from the exhaust pipe, it's definitely due to carbon buildup clogging the piston tops. Last week at the repair shop, the mechanic showed me the endoscope footage after removing the spark plugs—the carbon deposits on the back of the valves were thicker than rice crust. In such cases, cleaning is recommended, using walnut blasting or dry ice to blast it out. After cleaning, the throttle feels much lighter. However, for new cars within the first five years, it's really unnecessary—better spend that money on high-quality engine oil instead.

[SanCamila]

In our repair shop, 80% of the daily car cleaning services are unnecessary. Actually, you can tell whether a cleaning is needed by checking a few key indicators: if there's a popping sound during cold starts, if the idle is rough, or if the fuel consumption suddenly increases by two liters. For example, a Corolla owner complained about poor acceleration, and after testing, we found the cylinder pressure was 20% lower than normal due to combustion chamber leakage. In such cases, cleaning is indeed beneficial. However, those who push cleaning agents without even checking the car's condition, recommending two bottles right away, are just scamming money.

[ElijahLee]

The last combustion chamber cleaning test was quite interesting. Using an endoscope to inspect the piston top, the carbon deposits before cleaning looked like honeycomb briquettes, and after cleaning, the original metal color was revealed. Actual dyno test data showed that the 2.0T engine gained 11 Nm of maximum torque after cleaning. The exhaust emission test was even more noticeable—HC levels dropped from 258 ppm before cleaning to 187 ppm after. However, after driving 3,000 kilometers, the levels rebounded by about 20%. To me, it's like taking health supplements—effective but hard to sustain.