No. 21 ENGINE NOISE [13B-MSP]
| 21 | ENGINE NOISE |
|---|---|
| DESCRIPTION | Engine noise from under the hood. |
| POSSIBLE CAUSE | Squeal, click or chirp noise: Improper engine oil level Improper drive belt tension Rattle sound noise: Loose parts Hissing noise: Vacuum leakage Loose spark plug Air leakage from intake-air system Improper VFAD control system operation Rumble or grind noise: Improper drive belt tension Rap or roar noise: Exhaust system looseness Other noise: Oil pump drive gear noise Oil pump drive chain noise |
ENGINE NOISE - SYMPTOM TROUBLESHOOTING CHART
| STEP | INSPECTION | RESULTS | ACTION |
|---|---|---|---|
| 1 | Is squeal, click or chirp sound present? | Yes | Inspect the engine oil level or drive belts. |
| No | Go to the next step. | ||
| 2 | Is rumble or grinding noise present? | Yes | Inspect the drive belts. |
| No | Go to the next step. | ||
| 3 | Is rattle noise present? | Yes | Inspect the location of rattle for loose parts. |
| No | Go to the next step. | ||
| 4 | Is hissing noise present? | Yes | Inspect for the following: Vacuum leakage Spark plug looseness Intake-air system leakage VFAD control system operation (See ENGINE CONTROL SYSTEM OPERATION INSPECTION [13B-MSP] .) |
| No | Go to the next step. | ||
| 5 | Is rap or roar noise present? | Yes | Inspect the exhaust system for loose parts. |
| No | Go to the next step. | ||
| 6 | Is knocking noise present? | Yes | Go to the symptom troubleshooting "No. 13 Knocking/pinging/detonation-Acceleration/cruise". (See NO. 13 KNOCKING/PINGING/DETONATION-ACCELERATION/CRUISE [13B-MSP] .) |
| No | If the noise comes from engine internally, inspect for oil pump drive gear or chain noise. | ||
| 7 | Verify test results. If normal, return to the diagnostic index to service any additional symptoms. If the malfunction remains, inspect the related Service Bulletins and/or the On-line Repair Information and perform the repair or diagnosis. | ||
DIAGNOSTIC PROCEDURE
No. 22 VIBRATION CONCERNS (ENGINE) [13B-MSP]
| 22 | VIBRATION CONCERNS (ENGINE) |
|---|---|
| DESCRIPTION | Vibration from under hood or driveline. |
| POSSIBLE CAUSE | Loose installation bolts or worn parts Components malfunction such as worn parts |
VIBRATION CONCERNS - SYMPTOM TROUBLESHOOTING CHART
| STEP | INSPECTION | RESULTS | ACTION |
|---|---|---|---|
| 1 | Inspect the following components for loose installation bolts or worn parts: Cooling fan No. 1 Cooling fan No. 2 Drive belt and pulleys Engine mounts Are all the items normal? | Yes | Inspect the following systems: Wheels MT AT Driveline Suspension |
| No | Readjust or retighten the engine mount installation position. Service if necessary for other parts. | ||
| 2 | Verify test results. If normal, return to the diagnostic index to service any additional symptoms. If the malfunction remains, inspect the related Service Bulletins and/or the On-line Repair Information and perform the repair or diagnosis. | ||
DIAGNOSTIC PROCEDURE
Vibration Method
- If a malfunction occurs or becomes worse while driving on a rough road or when the engine is vibrating, perform the steps below.
Note. There are several reasons why vehicle or engine vibration could cause an electrical malfunction. Some of the things to check for are: Connectors not fully seated. Wiring harnesses not having full play. Wires laying across brackets or moving parts Wires routed too close to hot parts. An improperly routed, improperly clamped, or loose wiring harness can cause wiring to become pinched between parts. The connector joints, points of vibration, and places where wiring harnesses pass such as through the firewall and body panels are the major areas to be checked.