Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
DEFINITION: A light tapping noise with a frequency equal to one half engine speed, or any other varying frequency. | ||||
1 | Is there valve train noise? | -- | Problem solved. | |
2 | Check for a high engine oil level. An engine with the oil level above the FULL mark may allow the crankshaft counterweights to churn the oil into foam. When foamy oil is pumped into the lifters, the lifters become noisy. A solid column of oil ensures proper lifter operation. Is the oil level too high? | -- | ||
3 | Check for a low engine oil level. An engine with the oil level below the ADD mark may allow the oil pump to pump air at high engine RPMs. Is the oil level too low? | -- | ||
4 | Check for proper engine oil pressure. Refer to Engine Mechanical Specifications , Engine Mechanical Specifications (L57 P32/42) and Oil Pressure Diagnosis and Testing . Is the engine oil pressure within specifications? | -- | ||
5 | Check the oil pump screen for damage or a loose fit to the oil pump. Are the components worn or damaged? | -- | ||
6 | Check for a damaged oil pump or loose mounting bolts Refer to Oil Pump Clean and Inspect Are the components worn or damaged? | -- | ||
7 | Remove and inspect the valve rocker arms, valve rocker arm shafts, and pushrods. Refer to Valve Lifters and Guides Clean and Inspect . Are the components worn or damaged? | -- | ||
8 | Remove and inspect the valve lifters and guides. Refer to Valve Lifters and Guides Clean and Inspect . Are the components worn or damaged? | -- | ||
9 |
Are the components worn or damaged? | -- | ||
10 |
Refer to Timing Chain Wear Check and Timing Chain and Sprockets Clean and Inspect . Are the components worn or damaged? | -- | ||
11 | Perform a complete disassembly of the engine and inspect all internal engine components. Are the components worn or damaged? | -- | ||
