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. A 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? | -- | Drain the oil to the proper level. System OK | |
3 | Check for a low engine oil level. A engine with the oil level below the "Add" mark may allow the oil pump to pump air at high engine RPM's. Is the oil level too low? | -- | Add oil as required. System OK | |
4 | Check for proper engine oil pressure. Refer to 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. Is the oil pump screen loose or damaged? | -- | Repair as required. System OK | |
6 | 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? | -- | Repair as required. System OK | |
7 | Remove and inspect the valve lifters, rocker arms, and pushrods. Refer to Valve Rocker Arm and Pushrod Replacement and Valve Lifter Replacement. Are components worn or damaged? | -- | Replace the components as required. System OK | |
8 | Check camshaft lobe lift. Refer to Camshaft and Bearings Clean and Inspect and Engine Mechanical Specifications. Is the camshaft lobe lift within specified limits? | -- | Camshaft is OK | Replace the camshaft and valve lifters. System OK |
9 | Remove the engine front cover and inspect the timing chain, guide, and sprockets for excessive wear or damage. Refer to Timing Chain and Sprockets Clean and Inspect Are the components worn or damaged? | -- | Replace the components as required. System OK | |
10 | Perform a complete disassembly of the engine and inspect all components. | -- | -- | -- |
