What are the symptoms of a blown cylinder head gasket?
2 Answers
The manifestations of a blown cylinder head gasket vary depending on the location of the damage. If there's communication between the engine cylinder and the cooling water jacket or oil passage, you may observe yellow-black oil foam floating on the surface of the coolant in the radiator, or noticeable water contamination in the oil pan. In severe cases, the exhaust may contain water or engine oil. The cylinder head gasket, also known as the cylinder gasket, is located between the cylinder head and cylinder block. Its function is to fill microscopic gaps between these components, ensuring a tight seal at the joint surface, maintaining combustion chamber integrity, and preventing cylinder gas leakage or water jacket coolant leakage. Based on material composition, cylinder head gaskets can be classified into several types including metal-asbestos gaskets, metal composite gaskets, and all-metal gaskets.
I've been driving for decades and have encountered many cases of blown head gaskets. The most common symptom is thick white smoke from the exhaust pipe, resembling steam from a train - this happens when coolant leaks into the combustion chamber and gets burned. Then the engine temperature soars, with the coolant temperature gauge hitting the red line, accompanied by noticeable power loss where pressing the accelerator doesn't improve performance. Another telltale sign is milky emulsion under the oil cap, indicating mixed oil and coolant. The overall sensation includes increased engine vibration and hard starting. Continuing to drive in this condition may lead to engine seizure or complete failure, resulting in extremely expensive repairs. I always advise friends to stop and inspect immediately when noticing these signs - never push the engine to destruction. During maintenance, regularly check the cooling system and engine seals, as early detection and repair can save significant costs.
