Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
DEFINITION: A light tapping noise at one half engine speed, or any varying frequency. | ||||
1 | Is there valve train noise? | -- | System OK | |
2 | Check for a high engine oil level. An engine with the oil level above the Full mark allows 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 | Drain the engine oil to the proper level. Is the tapping noise gone? | -- | System OK | |
4 | 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 RPM. Is the oil level too low? | -- | ||
5 | Add the engine oil as required. Is the tapping noise gone? | -- | System OK | |
6 | Check for proper engine oil pressure. Refer to Oil Pressure Diagnosis and Testing . Is the engine oil pressure within specifications? | -- | ||
7 | Check the oil pump screen for damage or a loose fit to the oil pump. Is the oil pump screen loose or damaged? | -- | ||
8 | Repair the oil pump screen as required. Is the tapping noise gone? | -- | System OK | |
9 | Check for a damaged oil pump or loose mounting bolts. Refer to Oil Pump Replacement . Is the oil pump damaged or are the mounting fasteners loose? | -- | ||
10 | Repair the oil pump as required. Refer to Oil Pump Replacement . Is the tapping noise gone? | -- | System OK | |
11 | Remove and inspect the valve lifters, rocker arms, and pushrods. Refer to Valve Rocker Arm and Push Rod Replacement and Valve Lifter Replacement . Are components worn or damaged? | -- | ||
12 | Replace the valve lifters, rocker arms and push rods as required. Refer to Valve Rocker Arm and Push Rod Replacement and Valve Lifter Replacement . Is the tapping noise gone? | -- | System OK | |
13 | Check camshaft lobe lift. Refer to Camshaft and Bearings Cleaning and Inspection and Engine Mechanical Specifications . Is the camshaft lobe lift within specified limits? | -- | ||
14 | Replace the camshaft and valve lifters. Refer to Camshaft and Bearings Cleaning and Inspection and Engine Mechanical Specifications . Is the tapping noise gone? | -- | System OK | |
15 | Remove the engine front cover and inspect the timing chain, guide, and sprockets for excessive wear or damage. Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection . Are the components worn or damaged? | -- | ||
16 | Replace the timing chain, guide and sprockets as required. Refer to Camshaft Timing Chain and Sprocket Cleaning and Inspection . Is the tapping noise gone? | -- | System OK | |
17 | Perform a complete disassembly of the engine and inspect all components. Is inspection complete? | -- | System OK | -- |
