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Engine noise when starting, lasting only a few seconds (A20NFT/LHU)

Engine noise when starting, lasting only a few seconds (A20NFT/LHU)


Cause Procedure
Incorrect oil filter without check valve Fit the correct oil filter.
Incorrect oil viscosity
1. Drain the oil.

2. Fill oil of the correct viscosity.


High leakage rate valve clearance balancers Replace the valve clearance balancers if necessary.
Worn thrust bearing crankshaft
1. Check the thrust bearing and the crankshaft.

2. Repair or replace any defective or damaged components.


Damaged or defective bypass valve oil filter
1. Check that the oil filter's bypass valve is working correctly.

2. Repair or replace any defective or damaged components.


Malfunctions in camshaft position regulators - incorrect oil viscosity or contamination.
1. Check that the oil pressure is correct. If the pressure is low, inspect the bottom of the oil filter with regard to the return feed. See Diagnosis and testing of oil pressure (A20NFT/LHU) .

2. Isolate the noise to a specific camshaft position regulator. Disconnect the electrical connector from the camshaft position regulator's solenoid valves and start the car. If the noise disappears, repeat the procedure to limit it to a single actuator. Information is available in "Replacing the camshaft position intake actuator" or "Replacing the camshaft position exhaust actuator".