What Problems Can Excessive Carbon Deposits Cause to a Vehicle?

[MaxRose]

Excessive carbon deposits can lead to issues such as poor acceleration, difficulty starting, unstable engine idle, increased fuel consumption, and engine malfunctions. It is recommended to perform intake system maintenance once a year; conduct a deep fuel system maintenance after every 2-3 routine services; and perform engine lubrication system maintenance at least once every two years. Poor Acceleration: Carbon deposits reduce the intake passage, lower the charging efficiency, increase cylinder pressure, and delay ignition timing, resulting in decreased engine power. Difficulty Starting the Vehicle: Carbon deposits falling into the intake valve seat passage can cause insufficient cylinder pressure. During startup, the injected fuel is absorbed by the carbon deposits, leading to a lean air-fuel mixture in the cylinder and preventing the engine from starting properly. Unstable Engine Idle: When carbon deposits adhere to the intake valve and throttle valve, the engine cannot accurately control the amount of gasoline and air sent to the combustion chamber, causing unstable engine idle. Increased Fuel Consumption: When carbon deposits accumulate in the combustion chamber, they can easily cause knocking, delay ignition timing, reduce engine power, and increase fuel consumption by 4~5%.

[DeHaven]

I've been driving for over a decade and am all too familiar with carbon buildup issues. Carbon deposits get stuck in places like the engine intake valves and fuel injectors, worsening gasoline atomization. The most obvious symptom is the car feeling particularly sluggish when you step on the gas, as if dragging a rock. Fuel consumption keeps climbing, costing hundreds more in gas money each month. Cold starts also become difficult, with the engine shaking like it's breakdancing when you turn the key in the morning. Even worse, sudden stalling can occur - I once got stranded at an intersection waiting for a red light. Regular use of cleaning additives or highway driving to flush the system can effectively prevent these problems.

[HadleyFitz]

Carbon deposits are like blood clots in the arteries. When a layer of oil sludge builds up in the intake tract and combustion chamber, the engine struggles to breathe. You'll noticeably feel restricted power, sluggish acceleration, and extra difficulty when overtaking. Fuel consumption typically increases by 5% to 10%, becoming even worse with AC on. Cold starts become problematic accompanied by engine vibrations, and the steering wheel shakes so much at red lights it numbs your hands. Long-term neglect may even lead to engine knocking—listen for metallic 'clattering' sounds from the engine bay. It's best to use fuel system cleaner every 20,000 kilometers.

[SanBrooke]

Carbon buildup is quite problematic for daily driving. The throttle response becomes sluggish, and acceleration feels like stepping on cotton. The most annoying part is the inexplicable increase in fuel consumption—under the same road conditions, the range drops by dozens of kilometers. On winter mornings, it takes two or three attempts to start the engine, and the tachometer jumps like it's at a dance party. At idle, the car shakes so much that you can see ripples in a cup of water placed on the dashboard. Once, the exhaust even smelled foul, and a check revealed the catalytic converter was clogged too. Regularly driving at high speeds does help, as revving the engine can flush out some of the carbon deposits.

[SanEthan]

Carbon buildup to a certain extent can make your beloved car sick. The first noticeable symptom is a decrease in power, especially when climbing hills or accelerating, which becomes particularly strenuous. The fuel gauge drops noticeably faster, requiring more frequent refueling for the same distance traveled. The starting system is affected the most, with significantly longer warm-up times in the morning and a clicking sound during ignition. In the most severe cases, it can cause the combustion chamber temperature to rise, leading to piston ring ablation and rendering the engine useless. When parking, avoid prolonged idling as it makes carbon deposits more likely to accumulate. Using gasoline with cleaning additives can help alleviate the issue.