Coolant leak (Chevrolet Captiva 1)

Coolant has entered the combustion chamber

Inspection	Operation, action
Definition: Excessive white smoke from the tailpipe and/or a coolant odor may indicate coolant is present in the combustion chamber. Low coolant levels, an inefficient cooling fan, or a faulty thermostat can all lead to "overheating" conditions that can cause damage to engine components.
Preliminary inspection	Check for external coolant leaks. See. Section 1D1, Engine Cooling - 2.0 Diesel.
Localize damaged cylinders	Checking cylinder balance with a diagnostic tool Pressure testing of the cooling system Compression check
Visual inspection of the exhaust gas recirculation (EGR) system	Inspect the Exhaust Gas Recirculation (EGR) valve and intake system for signs of coolant leakage. If any problems are found, replace the EGR cooler.
Cylinder head gasket leak	Remove the cylinder heads from the row containing the damaged cylinder and inspect for damage. Replace components if necessary.
Damage to the cylinder head or engine block	Inspect the cylinder heads for cracks. Inspect the cylinder block for damage. Inspect the mating surface of the head to the cylinder block for straightness. Replace components if necessary.

Coolant has entered the engine oil

Cause	Elimination
Definition: Foamy or discolored oil, or overfilling the engine with oil, may indicate coolant is leaking into the crankcase. Low coolant levels, an inefficient cooling fan, or a faulty thermostat can cause "overheating" conditions that can damage engine components. Contaminated engine oil and a dirty oil filter should be replaced. Check the oil for excessive foaming or check for overfilling the engine with oil. Oil that is diluted with coolant may not lubricate the main bearings effectively, which could cause damage to engine components. See "Noise at the bottom of the engine regardless of engine speed" in this section. The test is performed by testing the cylinder for possible leaks. During this test, excessive air bubbles in the cooling system may indicate a faulty seal or damaged components. Inspect when checking the compression ratio in the cylinder. The presence of a low compression ratio in two adjacent cylinders of the engine block may indicate the destruction of the cylinder head gasket. See "Checking engine compression" in this section.
The cylinder head gasket is faulty	Replace the cylinder head gasket and components as necessary. See. Section 1B, Engine Mechanical System - 2.0 Diesel.
The cylinder head is deformed	Replace the cylinder head gasket. See. Section 1B, Engine Mechanical System - 2.0 Diesel.
The cylinder head is cracked	Replace the cylinder head and gasket.
Cracks in the engine block	Replace these engine components if necessary.
Porosity of the cylinder head, block or manifold	Replace these engine components if necessary.
Leak in the oil radiator of the engine cooling system	Replace components if necessary.