What Causes Engine Cylinder Scuffing?
4 Answers
Engine cylinder scuffing is caused by: 1. Severe lack of lubrication oil; 2. Rapid changes in the thermal expansion coefficient of metal components; 3. Excessive mechanical lubrication gap between the piston and cylinder wall; 4. Poor quality cylinder gasket with insufficient surface flatness; 5. Improper driving habits, such as long-term aggressive driving. Symptoms of engine cylinder scuffing include: 1. Engine power loss during driving, difficulty in acceleration, and air leakage sounds at the junction of the cylinder head and cylinder block; 2. One or two cylinders not functioning, with bubbles appearing at the radiator water filler; 3. Milky white engine oil when checking the dipstick; 4. Continuous water droplets flowing from the exhaust pipe.
During long-distance drives, I've seen quite a few cases of cylinder head gasket failure. The core issue lies in the aging or improper installation of the gasket. Under high temperature and pressure, that thin sealing layer of the cylinder head gasket can't withstand the stress and ruptures, allowing engine oil and coolant to mix. Once, my friend's car suddenly had coolant turning milky brown—that was engine oil leaking into the coolant passage. Aggressive driving over long periods increases the risk of engine block deformation, especially for older vehicles over ten years. A reminder to everyone: always monitor the temperature gauge, change coolant regularly, and be alert if you notice unexplained oil leaks under the chassis—it could be your engine sounding the alarm!
I've experienced two instances of cylinder head gasket failure, with the core issue lying in cooling system malfunction. Insufficient coolant led to localized overheating, causing the head gasket to become brittle and crack like burnt paper. This is particularly dangerous when climbing hills with AC on during summer, when the temperature gauge suddenly spikes into the red zone. During my last repair, the mechanic mentioned improper cylinder head bolt torque could also compromise sealing - issues that could arise from either factory assembly or subsequent repairs. Regularly check for oil droplets floating in the coolant reservoir, as this is often a precursor to head gasket failure.
The most challenging blown head gasket case I've repaired: The owner used substandard coolant which caused cylinder block corrosion and perforation. The metal was corroded with pinhole-sized holes, allowing 2000°C high-temperature gases from above the piston to directly enter the water channel. This situation often occurs in vehicles that haven't changed coolant for a long time, where acidic substances gradually eat away the metal. Monitoring whether the cooling fan operates properly is also crucial—I've seen cases where a seized fan caused cylinder head deformation in a short period.
