What are the effects of overfilling engine oil on the engine?
2 Answers
The effects of overfilling engine oil on the engine include: 1. Reduced vehicle power; 2. Increased fuel consumption; 3. Severe damage to the three-way catalytic converter. The functions of engine oil are: lubrication, auxiliary cooling, cleaning, sealing and leak prevention, rust and corrosion prevention, shock absorption, and anti-wear. The method for changing engine oil is: 1. Lift the vehicle, remove the protective plate, and place a container under the oil drain screw; 2. Loosen the oil drain screw, use an air gun to blow at the oil filler port for two minutes, tighten the oil drain screw after draining, and wipe it with a tissue to check for oil leakage; 3. Reinstall the protective plate, lower the vehicle, and add engine oil at the filler port.
After years of working as a mechanic, I've found that overfilling engine oil can cause significant damage. The most immediate issue is increased crankcase pressure. Excess oil gets whipped by the high-speed crankshaft, creating bubbles like whipped cream. These air bubbles reduce lubrication effectiveness, accelerating wear on critical components. Additionally, increased resistance leads to higher fuel consumption - my tests show adding half a liter can increase fuel use by about 1% per 100km. The worst problem is oil seals failing under pressure, causing leaks that may produce blue smoke if oil reaches the exhaust system. Always supervise technicians to ensure oil level stays at the midpoint between dipstick marks during maintenance.
