Engine Noise On Start-Up, But Only Lasting A Few Seconds - Chevrolet 5.7L Corvette 2004 Shop Manual

Stuck valves
Carbon buildup on the valve stem can cause
the valve not to close properly.
Excessively worn or mis-aligned timing
chain
Worn camshaft lobes
Sticking lifters
BASE ENGINE MISFIRE WITH COOLANT CONSUMPTION
Base Engine Misfire with Coolant Consumption
Faulty cylinder head gaskets and/or cracking or other
damage to the cylinder heads and engine block
cooling system passages - Refer to Diagnostic
Starting Point - Engine Cooling in Engine Cooling.
Coolant consumption may or may not cause the
engine to overheat.
BASE ENGINE MISFIRE WITH EXCESSIVE OIL CONSUMPTION
Base Engine Misfire with Excessive Oil Consumption
Cause
Worn valves, valve guides and/or
valve stem oil seals
Worn piston rings
Oil consumption may or may not
cause the engine to misfire.

ENGINE NOISE ON START-UP, BUT ONLY LASTING A FEW SECONDS

Repair or replace as required.
Replace the timing chain and sprockets as required.
Replace the camshaft and valve lifters.
Replace as required.
Cause
Inspect the spark plugs for oil deposits. Refer to Spark Plug
Inspection in Engine Controls - 5.7L.
Repair or replace as required.
Inspect the spark plugs for oil deposits. Refer to Spark Plug
Inspection in Engine Controls - 5.7L.
Inspect the cylinders for a loss of compression. Refer to
Engine Compression Test .
Perform cylinder leak down and compression testing to
determine the cause. Refer to Cylinder Leakage Test .
Repair or replace as required.
the top of the piston shows valve contact, replace
the piston and pin assembly.
Correction
Inspect for spark plugs saturated by
coolant. Refer to Spark Plug Inspection in
Engine Controls - 5.7L.
Perform a cylinder leak down test. Refer to
Cylinder Leakage Test .
Inspect the cylinder heads and engine block
for damage to the coolant passages and/or a
faulty head gasket. Refer to Coolant in
Combustion Chamber .
Repair or replace as required.
Correction