Engine - Knocking/Vibration While Driving

11-007

May 20, 2011

Applies To:
2004-08 TL - ALL

Knocking or Vibration While Driving

SYMPTOM

There is a knocking or vibration from under the front of the vehicle while driving.

PROBABLE CAUSE

High under-hood temperatures caused the front engine mount to crack and tear.

CORRECTIVE ACTION

Replace the front engine mount.





PARTS INFORMATION

WARRANTY CLAIM INFORMATION

The normal warranty applies.

Operation Number: 112102

Flat Rate Time: 1.0 hour

Failed Part: P/N 50830-SEP-A01

Defect Code: 01801

Symptom Code: 04501

Skill Level: Repair Technician

DIAGNOSIS

Bring the engine up to normal operating temperature (cooling fan cycles twice), and fully apply the parking brake. Open the hood.

M/T - equipped vehicles:
Stand to the side of the engine compartment, and watch the top of the front engine mount. Have an assistant run the engine at 2,000 rpm, and slowly engage the clutch. Look for contact between the top of the engine mount, and the bottom of the engine mount bracket, and listen for a knock.

A/T - equipped vehicles:
Stand to the side of the engine compartment, and watch the top of the front engine mount. Have an assistant shift the transmission into Drive. With the assistant's foot firmly on the brake pedal, have him quickly press the accelerator pedal and release it. Look for contact between the top of the engine mount and the bottom of the engine mount bracket, and listen for a knock.

Is there contact or a knock?

Yes - Go to REPAIR PROCEDURE.

No - This service bulletin does not apply. Continue with normal troubleshooting to find the source of the problem.

REPAIR PROCEDURE

1. Raise the vehicle on a lift.





2. Remove the engine undercover.

2004-06 models:





3. Disconnect the radiator fan motor connector and the harness clips.

4. Lower the vehicle.





5. Disconnect the air conditioner condenser fan motor connector, the harness clamps, and the upper radiator hose. Pinch the upper radiator hose with hose-pinching pliers to minimize the loss of coolant.





6. Remove the A/C condenser fan shroud assembly and the radiator fan shroud assembly.





7. Remove the front engine mount mounting nuts, the front engine mount stop, and the mounting bolt. Disconnect the vacuum hose on models with M/T.





8. Remove the four bolts holding the front engine mount to the subframe.

9. Place a floorjack and a wood block under the transmission next to the engine, and raise the transmission until the engine mount bracket clears the engine mount stop.

10. Remove the engine mount through the top of the engine compartment.

11. Using four new bolts, loosely install the the new front engine mount to the subframe, and reconnect the vacuum hose (M/T models).

NOTE:
Do not torque the bolts yet.

12. Lower the transmission, and remove the floor jack.





13. Torque the four mounting bolts.





14. Reinstall the front engine mount bolt, the front engine mount stop, and the mount nuts.





15. Reinstall the radiator fan and shroud assembly, then reinstall the A/C condenser fan and shroud assembly.





16. Reconnect the A/C condenser fan motor connector, the harness clamps, and the upper radiator hose.





18. Reconnect the radiator fan motor connector and the harness clips.





19. Reinstall the engine undercover.

20. Lower the vehicle.

21. Top off the coolant in the radiator, and in the coolant reservoir.





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