22 · Diagnostics

Engine coolant leaks

Make: Alfa Romeo
Model: 147 Factory Service Manual
Year: 2000–2004
Section: Consumption /leaks/ wear › Engine coolant leaks

‹ Prev Engine coolant consumption Next › Engine oil leaks

Fault diagnosisEngine coolant leaks

ENGINE COOLANT LEAKS

1.6 TS, 2.0 TS

A leak of engine coolant is seen with dripping and/or fouling of the engine

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Preliminarily carry out a visual inspect to locate the component or area which is leaking. Check that there is no engine oil in the coolant. Check that there is no water or emulsion in the engine oil. If the visual inspection is insufficient, wash the engine, dry it and let it slowly reache operating temperature: to identify the leak, if necessary, carry out the system leakage test Op. 0510C30	No leak located: Continue to Step 1	Leak from the pipes	Continue to Step 1
			Leak from the radiator	Continue to Step 2
			Leak from the expansion tank	Continue to Step 3
			Leak from the water pump	Continue to Step 3
			Leak from the thermostat unit	Continue to Step 4
			Leak from the cylinder head	Continue to Step 6
			Leak from the heater radiator	Continue to Step 7
			Seepage of oil or water between the engine and the cooling circuit	Continue to Step 8
1	PIPES CHECK	All OK	Problems met	Operation
	Check the condition and seal of the pipes. In particular: condition and correct fitting of the bands condition of hoses, connectors and plugs	Continue to Step 2	Tightening not correct or components damaged	Restore the correct tightening or replace the components involved
2	CHECK ON RADIATOR	All OK	Problems met	Operation
	Check the condition of the radiator	Continue to Step 3	Radiator damaged or distorted	Reaplce the radiator Op. 1088B20
3	CHECK EXPANSION TANK	All OK	Problems met	Operation
	Visually inspect: the condition of the expansion tank; the seal of the plug Check the condition of the breather valve in the cap	Continue to Step 4	Tank damaged or distorted	Replace the tank Op. 1088B10or cap
4	THERMOSTAT UNIT CHECK	All OK	Problems met	Operation
	Visually inspect: the condition of the thermostat unit; the seal of the gaskets	Continue to Step 5	Thermostat group faulty	Replace the thermostat unit or the seals Op. 1088C40
5	CHECK ON WATER PUMP	All OK	Problems met	Operation
	Visually inspect: the condition of the water pump; the seal of the gaskets	Continue to Step 6	Water pump faulty	Replace the water pump or the gaskets Op. 1088C10
6	CHECKING CYLINDER HEAD GASKET	All OK	Problems met	Operation
	Check: that the cylinder head tightening is correct that the gasket is not leaking	Continue to Step 7	Cylinder head tightening not correct	Restore the correct tightening
		Continue to Step 7	Gasket damaged	Replace the seal Op. 1016C10
7	CHECK ON HEATER RADIATOR CHECK ON CYLINDER HEAD GASKET	All OK	Problems met	Operation
	Check the condition of the heater radiator	Continue to Step 8	Heater radiator damaged or distorted	Reaplce the radiator Op. 5040C50
8	CYLINDER BLOCK/CRANKCASE PLANE CHECK	All OK	Problems met	Operation
	Remove the cylinder head Op. 1016C10 That that the following are absent: oily dross on the valves; defects in the cylinder block/crankcase plane; defects in the cylinder head gasket;	Continue to Step 9	Cylinder block/crankcase plane defective	Reface the cylinder block/crankcase
		Continue to Step 9	Presence of oily dross on the valves	Overhaul the cylinder head Op. 1016E10
9	CHECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Check that the fault is no longer present		Fault persists	Search for the fault starting from another symptom'

1.9 JTD 16V

A leak of engine coolant is seen with dripping and/or fouling of the engine

0	PRELIMINARY CHECKS	All OK	Problems met	Operation
		Results of the tests
	Preliminarily carry out a visual inspect to locate the component or area which is leaking. Check that there is no engine oil in the coolant. Check that there is no water or emulsion in the engine oil.	Continue to Step 8	Leak from water pipes	Continue to Step 1
			Leak from the radiator	Continue to Step 2
			Leak from the expansion tank	Continue to Step 3
			Leak from the water pump	Continue to Step 4
			Leak from the thermostat unit	Continue to Step 5
			Leak from the heater radiator	Continue to Step 6
			Outside leak from the cylinder head	Continue to Step 7
			Leak from cylinder block/cylinder head plugs	Replace the plugs
1	PIPES CHECK	All OK	Problems met	Operation
	Check the condition and seal of the pipes. In particular: condition and correct fitting of the bands condition of hoses, connectors and plugs	Continue to Step 8	Tightening not correct or components damaged	Restore the correct tightening or replace the components involved
2	CHECK ON RADIATOR	All OK	Problems met	Operation
	Check the condition of the radiator	Continue to Step 8	Radiator damaged or distorted	Reaplce the radiatorOp. 1088B24
3	CHECK EXPANSION TANK	All OK	Problems met	Operation
	Visually inspect: the condition of the expansion tank; the seal of the plug Check the condition of the breather valve in the cap	Continue to Step 8	Tank damaged or distorted	Replace the tank or cap Op. 1088B10
4	CHECK ON WATER PUMP	All OK	Problems met	Operation
	Visually inspect: the condition of the water pump; the seal of the gaskets	Continue to Step 8	Water pump faulty	Replace the water pump or the gaskets Op. 1088C12
5	THERMOSTAT UNIT CHECK	All OK	Problems met	Operation
	Visually inspect: the condition of the thermostat unit; the seal of the gaskets	Continue to Step 8	Thermostat unit faulty	Replace the thermostat unit or seals Op. 1088C30
6	HEATER RADIATOR CHECK	All OK	Problems met	Operation
	Check the condition of the heater radiator	Continue to Step 8	Heater radiator damaged or distorted	Replace the heater radiatorOp. 5030A50
7	CHECKING CYLINDER HEAD	All OK	Problems met	Operation
	Remove the head. Check: That the planarity of the cylinder head plane is correct That the planarity of the cylinder head support surface on the cylinder block is correct;	Continue to Step 8	Cylinder head plane defective	Regrind the cylinder head plane
			Cylinder block/crankcase plane defective	Regrind the cylinder block/crankcase plane
			Planes correct, head gasket faulty	Replace the cylinder head gasket
8	CHECK ON CORRECT OPERATION	All OK	Problems met	Operation
	Check that the fault is no longer present	End of diagnosis

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Parts & tools for this job For 2000 Alfa Romeo 147

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