Is it problematic if the cold engine oil exceeds the upper limit?
2 Answers
It is problematic if the cold engine oil exceeds the upper limit, with the following impacts: reduced engine power, oil burning, and carbon buildup. The functions of engine oil include: lubrication, auxiliary cooling, cleaning, sealing to prevent leaks, rust and corrosion prevention, shock absorption, and wear resistance. Engine oil is categorized into mineral oil, semi-synthetic oil, and fully synthetic oil. The method for changing engine oil is: 1. Lift the car, remove the underguard, and place a container of about 10 liters under the oil drain plug; 2. Unscrew the oil drain plug, use an air gun to blow for two minutes at the oil filler port, then tighten the oil drain plug after draining and wipe it with a tissue to check for leaks; 3. Reinstall the underguard and lower the car, then use a funnel to add engine oil through the filler port.
I often help neighbors check their cars in the garage, and exceeding the oil level when the engine is cold is indeed a problem. I've just dealt with a similar situation where too much oil increases internal engine pressure, which can crush oil seals and cause leaks. In severe cases, it can also raise crankcase pressure, affecting lubrication efficiency. Once, my relative drove without checking, and shortly after the oil exceeded the limit, the car started making strange noises, costing hundreds in repairs. I recommend carefully measuring with the dipstick during cold checks—the safe zone is between the upper and lower limits. If it's overfilled, don't take it lightly; use professional equipment to extract the excess oil or drive directly to a repair shop for proper handling. During regular oil changes, also be cautious not to overfill. Some shops might accidentally add too much oil to save effort, so car owners should double-check themselves.
