| Table 1: | Momentary Noise |
| Table 2: | Intermittent Noise |
| Table 3: | Noise at Slow Idle |
| Table 4: | Noise at High Engine Speed |
| Table 5: | Noise at Idle, Louder at Higher Speed |
| Table 6: | 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 lifters which hold the valves open when the engine is not running. The lifter needs a few seconds to fill with oil after you start the engine. | -- | -- | No correction is needed |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
DEFINITION: Intermittent noisy on idle only, disappears when engine speed increases | ||||
1 |
Are the lifters dirty? Are the lifters damaged? | -- | System OK | |
2 | Replace the valve lifter. Refer to Valve Lifter Replacement | -- | -- | -- |
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 | The lifter has a high leak down rate. | -- | Replace the faulty lifter | -- |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
DEFINITION: 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 lifters, the 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 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. 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 "L" (Low) range, or 30 to 35 mph "D" (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 more valves. This noise is caused by one or more of the following:
| -- | 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? | -- | -- | |
3 | If the valve spring is more than 1.6 mm (1/16 in) off-square, replace the spring. | -- | -- | -- |
Step | Action | Value(s) | Yes | No |
|---|---|---|---|---|
DEFINITION: Valves noisy regardless of engine speed. | ||||
1 |
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. | -- | Replace the hydraulic lifter | -- |
