What are the symptoms of a bad cylinder head gasket?
3 Answers
The symptoms of a bad cylinder head gasket are: 1. Gas leakage between adjacent cylinders; 2. Leakage from the cylinder head; 3. High-pressure gas entering the cooling water jacket; 4. Communication between the engine cylinder and the cooling water jacket or lubricating oil passage. A cylinder is a cylindrical metal component that guides the piston to perform linear reciprocating motion inside the cylinder, consisting of the cylinder barrel, end cover, piston, piston rod, and sealing elements. The causes of a bad cylinder head gasket include: 1. Elongation or loosening of cylinder head bolts and nuts; 2. Deformation of the mating surface between the cylinder head and the engine block; 3. Improper installation that does not meet technical requirements; 4. Engine overheating; 5. Poor quality of the cylinder gasket itself.
If the cylinder head gasket is damaged, the symptoms are quite obvious. The engine temperature will fluctuate wildly, and the coolant temperature gauge will max out; oil mixes into the coolant reservoir, turning its color murky like milk tea; the power drops significantly, making acceleration sluggish; white smoke comes out of the exhaust pipe with a slightly sweet smell; the car shakes and makes loud rattling noises; coolant leaks rapidly, leaving puddles under the car after parking. I experienced it once—ignoring it ruined the engine, causing compression ratio drop and cylinder head deformation, costing tens of thousands to fix. If you notice these signs, get it checked immediately to avoid bigger issues. Regular coolant changes can save you a fortune in the long run.
My car had the same issue last time, and the symptoms were too obvious. The coolant temperature warning light flashed, and the engine was too hot to touch; there was milky white foam under the oil cap, clearly indicating coolant contamination; it lacked power when accelerating, struggling even on small inclines; the exhaust pipe emitted thick white smoke, like steam; the coolant level dropped rapidly, requiring constant top-ups; the engine also rattled, making highway driving nerve-wracking. I immediately pulled over and found out it was due to a blown head gasket causing a seal failure. Addressing it early prevents more expensive engine damage—otherwise, oil degradation or cylinder pressure issues could become serious. Regular maintenance should include seal checks to prevent this.
