NO. 21 ENGINE NOISE [LF]
| 21 | ENGINE NOISE |
|---|
| DESCRIPTION | Engine noise from under hood. |
| POSSIBLE CAUSE | Squeal, click or chirp noise: Improper engine oil level Improper drive belt tension Generator installation (alignment) Splash shield or under cover looseness (splashed water to drive belts) Rattle sound noise: Loose parts Hiss sound noise: Vacuum leakage Loose spark plug Air leakage from intake-air system Rumble or grind noise: Improper drive belt tension Loose parts Air in power steering fluid Improper P/S fluid level Rap or roar noise: Dynamic dumper looseness Exhaust system looseness Intake-air system looseness Other noise: Camshaft friction gear noise or tappet noise Timing chain noise |
| STEP | INSPECTION | RESULTS | ACTION |
|---|
| 1 | Is a squealing, click or chirping sound present? | Yes | Inspect for the followings: Engine oil level Drive belt tension Splash shield or under cover looseness Generator installation (alignment) |
| No | Go to the next step. |
| 2 | Is a rumbling or grinding noise present? | Yes | Inspect for the followings: Drive belt tension Loose parts in engine compartment P/S fluid level Repair or replace malfunctioning part according to inspection result. If normal, perform the power steering fluid line air bleeding. |
| No | Go to the next step. |
| 3 | Is a rattling noise present? | Yes | Inspect rattling location for loose parts. |
| No | Go to the next step. |
| 4 | Is a hissing noise present? | Yes | Inspect for the following: Vacuum leakage Spark plug looseness Intake-air system leakage |
| No | Go to the next step. |
| 5 | Is a rapping or roar noise present? | Yes | Inspect looseness for followings: Dynamic dumper Intake-air system Exhaust system |
| No | Go to the next step. |
| 6 | Is a knocking noise present? | Yes | Go to the symptom troubleshooting "No. 13 Knocking/pinging-acceleration/cruise". (See NO. 13 KNOCKING/PINGING-ACCELERATION/CRUISE [LF] ). |
| No | If the noise comes from the engine internal, inspect for friction gear, timing chain or tappet noise. |
| 7 | Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [LF] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF] ). |
NO. 22 VIBRATION CONCERNS (ENGINE) [LF]
| 22 | VIBRATION CONCERNS (ENGINE) |
|---|
| DESCRIPTION | Vibration from under hood or driveline. |
| POSSIBLE CAUSE | Loose attaching bolts or worn parts Components malfunction such as worn parts |
| STEP | INSPECTION | RESULTS | ACTION |
|---|
| 1 | Inspect the following components for loose attaching bolts or worn parts: Cooling fan Drive belt and pulleys Generator Engine mounts Exhaust system mounts All items normal? | Yes | Inspect the following systems: Wheels AT Driveline Suspension |
| No | Readjust or retighten engine mount installation position. Service if necessary for other parts. |
| 2 | Verify test results. If normal, return to diagnostic index to service any additional symptoms. (See SYMPTOM DIAGNOSTIC INDEX [LF] ). If malfunction remains, inspect related Service Bulletins and/or On-line Repair Information and perform repair or diagnosis. If vehicle is repaired, troubleshooting completed. If vehicle is not repaired or additional diagnostic information is not available, replace the PCM. (See PCM REMOVAL/INSTALLATION [LF] ). |
Vibration Method
- If 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 vehicle or engine vibration could cause an electrical malfunction. Inspect the following: Connectors not fully seated Wiring harnesses not having full play Wiring harnesses laying across brackets or moving parts Wiring harnesses 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.
Scheme 12
Scheme 12: Inspection Method for Switch Connectors or Wiring Harnesses
- Connect the M-MDS to the DLC-2.
- Turn the ignition switch to the ON position (Engine off). NOTE: If the engine starts and runs, perform the following steps during idle.
- Access PIDs for the switch you are inspecting.
- Turn the switch on manually.
- Slightly shake each connector or wiring harness vertically and horizontally while monitoring the PID. If PID value is unstable, inspect for poor connection.
Scheme 13
Scheme 13: Inspection Method for Sensor Connectors or Wiring Harnesses
- Connect the M-MDS to the DLC-2.
- Turn the ignition switch to the ON position (Engine off). NOTE: If the engine starts and runs, perform the following steps during idle.
- Access PIDs for the switch you are inspecting.
- Slightly shake each connector or wiring harness vertically and horizontally while monitoring the PID. If PID value is unstable, inspect for poor connection.
