Reasons for Diesel Engine Coolant Loss Without Visible Leaks?

1 Answers
JanelleMarie
07/30/25 1:59am
Coolant loss without visible leaks occurs because the engine operates at high temperatures, causing elevated coolant system pressure. Minor leaks may evaporate instantly due to the heat, making them difficult to detect. Potential causes include: an unsealed radiator cap allowing coolant to enter the expansion tank without returning, or a deteriorated thermostat gasket leading to leakage. Reason 1: Faulty radiator cap seal. Reason 2: Loose hose connections or leaking hoses. Reason 3: Cracked engine block or damaged cylinder head gasket causing coolant migration. Reason 4: Damaged oil cooler gasket or casting defects leading to coolant mixing. Reason 5: Heater core leakage.
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