How Often Should a Sedan Engine Be Cleaned?
4 Answers
For cleaning the internal lubrication system and carbon deposits of the engine, a deep cleaning is recommended approximately every 50,000 kilometers. 1. Purpose: The purpose of engine cleaning is to remove carbon deposits. If the vehicle has no carbon deposits, cleaning is completely unnecessary. Cleaning once every 40,000 to 50,000 kilometers is sufficient. If there are excessive carbon deposits, cleaning is required (excessive carbon deposits can lead to poor engine ignition, body shaking, etc.). 2. Cleaning Interval: The cleaning interval is related to the usual maintenance of the engine. Generally, frequent oil changes and air filter replacements are recommended. Avoid using low-quality fuel, and engine cleaning may not be necessary. You can check the exhaust port of the muffler; if there is no excessive carbon deposit inside when touched by hand and the fingers do not turn black, it indicates normal engine combustion without carbon deposit issues.
I've been driving for over 20 years, and engine cleaning really depends on the situation. If you frequently drive on construction sites or muddy roads, you should clean it every three months; otherwise, dust sticking to the oil pipes can easily cause short circuits. But if you mainly drive in the city and the engine stays clean, cleaning it every six months is sufficient. Remember to let the engine cool down before cleaning. It's best to use a neutral foam cleaner, spray it on, and gently scrub off the oil sludge with a soft brush—never rinse the electrical system directly with water! My older car has many wiring connectors, and last time water got in, it nearly blew a fuse. By the way, don’t mix carbon deposit cleaning with this; it’s more scientific to handle it separately every 20,000 kilometers.
I'm particularly passionate about maintenance details, and seasonal engine bay cleaning is most logical. Spring brings heavy windblown sand, necessitating a thorough cleaning before summer; autumn sees abundant dead leaves and insects, requiring another cleaning before temperatures drop. Each session takes under 30 minutes: after the engine cools completely, cover the alternator and fuse box with wiring protection film, spray specialized cleaner and let it sit for five minutes, then rinse with a low-pressure water gun. Focus on removing oil deposits near the throttle body - dirt buildup here causes fuel consumption to spike. I also wipe the underside of the hood weekly with a damp cloth to prevent long-term oil corrosion of rubber components. For internal cleaning, the manual recommends fuel system cleaning at 40,000 km, which in practice noticeably reduces engine vibration.
I believe cleaning the engine compartment should be based on actual usage frequency. I commute 30 kilometers daily, park in a garage with minimal dust, so I only clean it twice a year. However, after driving on coastal highways, it must be washed immediately—sea salt corrosion is more dangerous than carbon buildup. The critical step during cleaning is disconnecting the negative battery terminal; don't blindly trust no-rinse cleaners. Last time, using the wrong product caused the oxygen sensor to fail, costing 800 yuan to repair. Fuel system cleaning is recommended every 50,000 kilometers—don't be fooled into doing it early unless cold starts are noticeably difficult. After cleaning, remember to check the waterproof covers on wire connectors, as many older cars suffer from water leakage and electrical issues.
