What Causes the Engine to Make a Ticking Sound?

[OKinsley]

Engine noise may be caused by the following aspects: 1. Valve Noise: After starting the engine, you may hear a "ticking" sound, which is the sound of the valves. This is especially noticeable when the engine is cold because the oil pressure hasn't built up yet, and the valves aren't properly lubricated. The sound usually goes away after a short while. This is common if the car has been parked for a long time. 2. Insufficient Lubrication: Most cars will have slightly louder engine noise during a cold start compared to when the engine is warm. As long as the sound is even and smooth, not harsh, it's usually not a problem. This happens because, when cold, the gap between the cylinder wall and the piston hasn't reached the optimal size, and the oil lubrication isn't fully effective. Typically, when the engine block temperature reaches around 95 degrees, the sound will return to normal. 3. Oil Issues: Poor-quality oil, overdue oil changes, or low oil levels can increase friction between the valves and guides, as well as hydraulic lifters, making various engine noises more pronounced.