What Causes the Gurgling Sound from the Exhaust Pipe in Winter?

[Leroy]

Winter exhaust pipe gurgling sounds occur because: the air-fuel mixture is too rich and not completely burned, combined with prolonged combustion time in the cylinder. When the engine begins the next power stroke, unburned combustible mixture enters the exhaust pipe along with the expelled exhaust gases. Upon encountering fresh air in the exhaust pipe, this mixture reignites, producing the gurgling sound. Methods for maintaining the exhaust pipe include: 1. Preventing water from entering the exhaust pipe interior; 2. Applying anti-rust oil inside the exhaust pipe; 3. Regularly inspecting the exhaust pipe condition; 4. Avoiding prolonged high-revving while stationary.