What are the reasons for rapid coolant consumption without leakage?

[McJohn]

Coolant is consumed quickly without leakage due to: internal engine leakage, which is a rare occurrence and can be identified by checking the engine oil. Functions of coolant: 1. Provides anti-corrosion protection for cooling system components; 2. Prevents scale formation to avoid reducing the radiator's heat dissipation efficiency; 3. Ensures the engine operates within the normal temperature range. Precautions for using coolant in vehicles: 1. Avoid mixing different types of coolant; 2. Refrain from using inferior quality coolant; 3. Do not directly add concentrated coolant to prevent coolant deterioration and low-temperature thickening.