Is a knock noise heard under all engine speeds?

Go to Step 2

System OK

Inspect the crankshaft connecting rod journal.

Is the crankshaft connecting rod journal worn?

Go to Crankshaft Replacement

Go to Step 3

Measure the oil pump pressure.

Is the oil pump pressure low?

Go to Oil Pressure Diagnosis and Testing

Go to Step 4

Inspect the crankshaft connecting rod journals.

Are the journals out-of round?

Go to Crankshaft Replacement

Go to Step 5

Inspect the connecting rods.

Is there a misaligned connecting rod?

Go to Crankshaft Replacement

Go to Step 6

Inspect the connecting rod bolts.

Are the connecting rod bolts torqued properly?

System OK

Go to Crankshaft Replacement