How often should the intake tract be cleaned?
4 Answers
The intake tract should be cleaned every 20,000 to 40,000 kilometers. The cleaning method is as follows: 1. Remove the fuel injector and intake manifold attachments; 2. Remove the ignition coil and spark plugs; 3. Inject the cleaning agent into the intake tract and spark plug installation points; 4. Use a vacuum tank to extract the cleaning fluid accumulated in the cylinders. The benefits of cleaning the intake tract include: 1. Removing carbon deposits and gum from the throttle body, throat pipe, and intake pipe walls; 2. Improving intake tract performance to restore normal air-fuel ratio, reduce exhaust emissions, and stabilize engine idle; 3. Enhancing the performance of oxygen sensors and catalytic converters; 4. Improving fuel combustion.
My car has nearly 40,000 kilometers on it, and the mechanic reminded me during the last maintenance that it's time to clean the intake tract. Actually, this depends on your driving conditions: if you frequently drive in congested urban areas, you should check for carbon buildup at 20,000 kilometers; if you mostly drive on highways, cleaning every 30,000 kilometers is fine. Additionally, the cleanliness of 92 and 95 octane fuels differs, so users of 92 octane are advised to perform maintenance earlier. Once, I forgot to clean it and clearly felt the throttle becoming heavier and fuel consumption increasing. When I opened it up, the inside was black with carbon buildup almost clogging it. Don’t worry about the hassle—cleaning takes just about an hour and costs around 200-300 yuan, but it can save you more on fuel in the long run.
There's no fixed schedule for intake tract cleaning; it depends on the vehicle's condition. Personally, I prefer to do it every 30,000 kilometers, but my colleague who drives for ride-hailing services cleans it at 20,000 kilometers. Be aware that prolonged low-speed driving or frequent driving in cities with high PM2.5 levels can accelerate carbon buildup. Once, my engine shook severely during a cold start, and the repair shop said it was due to a dirty intake tract—it ran smoothly immediately after cleaning. It's advisable to have the mechanic check the carbon deposit thickness with a borescope during each oil change; if it exceeds 3 millimeters, it's time to clean. Additionally, direct injection engines are more prone to carbon buildup, so they require more frequent maintenance compared to port fuel injection vehicles.
For the first three years of a new car, you generally don't need to worry about cleaning the intake tract. Start paying attention after exceeding 50,000 kilometers. The advice from the repair shop is: clean it at 30,000 kilometers under normal usage, but if you notice sluggish acceleration, increased fuel consumption, or a pungent exhaust smell, you should clean it immediately. Personally, I've cleaned it twice in four years, both times before winter. In northern regions, low winter temperatures make it easier for condensation to form, causing oil sludge to solidify faster. Nowadays, there are no-disassembly cleaning agents available—just spray them in and let the engine idle for 20 minutes. However, stubborn carbon deposits still require disassembly for thorough cleaning.
