| Table 1: | Momentary Noise On Engine Startup |
| Table 2: | Intermittent Noise on Idle Only |
| Table 3: | Noise at Slow Idle |
| Table 4: | Noise at High Vehicle Speeds |
| Table 5: | Noise at Idle, Becomes Louder at High Engine Speed |
| Table 6: | Valve Noise Regardless of Engine Speed |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
DEFINITION: Momentary noise when the engine is started | ||||
1 | This condition is normal. Oil drains from the valve lifters which hold the valves open when the engine is not running. The valve lifter needs a few seconds to fill with oil after you start the engine. Does the noise stop? | -- | System OK | -- |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
DEFINITION: Intermittent noisy on idle only, disappears when engine speed increases | ||||
1 | Inspect the valve lifters. Refer to Valve Lifter Replacement .
Are the valve lifters dirty? Are the valve lifters damaged? | -- | System OK | |
2 | Replace the valve lifter(s). Is the inspection complete? | -- | System OK | -- |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
DEFINITION: Noisy at slow idle or with hot oil, quiet at higher engine speeds or with cold oil | ||||
1 | Inspect valve lifter(s) for high leakdown rate. Does the valve lifter have a high leakdown rate? | -- | Replace the faulty valve lifter(s) | No correction is needed |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
DEFINITION: Valve lifters noisy at high vehicle speeds, quiet at low speeds | ||||
1 | Check for a high engine oil level. An oil level above the "Full" mark allows the crankshaft counterweights to churn the oil into foam. When foam is pumped into the valve lifters, the valve lifters become noisy since a solid column of oil ensures proper operation. Is the oil level too high? | -- | Drain the oil to the proper level | |
2 | Check for a low engine oil level. Oil level below the "Add" mark allows the oil pump to pump air at high speeds. This causes noisy valve lifters. Is the oil level too low? | -- | Add oil as required | |
3 | Check the oil pan. Is the oil pan bent against the oil pump pickup? | -- | Repair as required | |
4 | Check the oil pump screen. Refer to Oil Pan Replacement . Is the oil pump screen bent or loose? | -- | Repair as required | System OK |
Step | Action | Value(s) | Yes | No | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
DEFINITION: Noisy at idle, becoming louder as engine speed increases to 1500 RPM | ||||||||||||||
1 | This noise is not connected with lifter malfunction. The noise becomes noticeable in the vehicle at 10 to 15 mph "Low" range, or 30 to 35 mph "Drive" range. The noise is described as a "ticking" sound. At slow idle, the sound may be entirely gone or appear as a light ticking noise in one or more valves. This noise is caused by one or more of the following:
Are any components damaged or worn excessively? | -- | Repair as necessary | |||||||||||
2 | The noise may be an off-square valve spring. You can eliminate this noise by rotating the valve spring and valve.
Is the valve spring off-square? | -- | If the valve spring is more than 1.6 mm (1/16 in) off-square, replace the spring. | System OK | ||||||||||
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
DEFINITION: Valves noisy regardless of engine speed. | ||||
1 | Check for excessive valve lash. To check for valve lash, turn the engine so that the piston in the cylinder is on TDC of the firing stroke. If valve lash is present, you can move the push rod freely up and down a certain amount with the rocker arm held against the valve. Check for a worn push rod upper end ball. Is the push rod upper end ball worn? | -- | Replace the push rod and rocker arm | |
2 | Check for a bent push rod. Is the push rod bent? | -- | Replace the push rod | |
3 | Check the lubrication system feed to the push rod and check to see if the push rod is properly lubricated. Is the push rod and feed system properly lubricated? | -- | Replace the push rod and rocker arm | |
4 | Check for a loose or damaged rocker arm. Is the rocker arm loose or damaged? | -- | Replace the rocker arm | |
5 | If you do not need to replace the push rod or the rocker arm, this indicates trouble in the hydraulic lifter or camshaft. Is the camshaft worn or damaged? | -- | Replace the camshaft and hydraulic lifters | Replace the lifter (s) as necessary |
