Troubleshooting - Cylinder Head Gasket

Symptoms / Cause / Notes

A Coolant level constantly decreases
Coolant enters the combustion chambers in very small amounts. This may continue for a long time without other symptoms. Another cause: leaks in the cooling system

B At operating temperature a white exhaust plume trails the vehicle, high water loss
Coolant enters the combustion chambers in large amounts, evaporates there and exits through the exhaust pipe as a white plume

C Air bubbles come from the open coolant expansion tank with the engine running, or a considerable amount of coolant escapes when the cap is opened
Exhaust gases enter the cooling system. The expansion tank opening smells of exhaust gases

D A shimmering, rainbow-colored or black film appears on the coolant surface
Oil from the engine lubrication system enters the cooling system

E The oil dipstick shows a gray or brown emulsion; water bubbles in the oil
Coolant has entered the lubrication system. Warning: water in the engine can damage the bearings. Replace the cylinder head gasket immediately (yourself or at a workshop). Do not run the engine further; have the vehicle towed to a workshop.