Engine - Idle Vibration or Rough Idle In DRIVE Range

90mazda06 Category B
Applicable Model/s 1990- '91 323/Protege'
Subject IDLE VIBRATION IN "D" RANGE
Bulletin No. 006/90
Issued 12/19/90
Revised
DESCRIPTION

Excessive vibration may be felt in the steering wheel and seats while idling in "D" range, especially when an electrical load is applied. For the proper repair procedures, refer to the instructions in this bulletin.

NOTE:
The customer may also describe this complaint as a low or rough idle and may not necessarily complain of vibration. Therefore, confirm the customer complaint carefully before attempting any repair.


VIN OF PRODUCTION CHANGE

The rubber used in No. 1 and No. 4 engine mounts and radiator lower mounts has been changed as follows:

No. 1 Engine Mount: JM1BG****M0236751 November 1, 1990
No. 4 Engine Mount: JM1BG****L1080134 May 1, 1990
Radiator Lower Mount: JM1BG****L0186254 June, 1989


PARTS INFORMATION


PART NUMBER

NEW OLD DESCRIPTION QTY

B456 39 040C B456 39 040B No. 1 Engine Mount Rubber 1

B455 39 070D B455 39 070C No. 4 Engine Mount Rubber 1

B61N 15 202A B366 15 202B Radiator Lower Mount 2


REPAIR PROCEDURE

1. Check if the idle speed is within specification. If it is not, connect the system selector (49B0 19 9A0) and set TEST SW to SELF-TEST. Adjust the idle speed to 750 rpm.

Idle Speed: 750 +/- 50 rpm



2. Verify that the cooling fan coupler and harness are not pinched between the radiator, air cleaner and duct. If necessary, reroute the harness.

3. Check to see if the condenser and the air conditioner pipe are rubbing. If necessary, adjust the position of the air conditioner pipe.



4. Check the location of the radiator upper bracket.

a) The plastic radiator stud ("A") should be centered within the upper bracket damper as shown in the illustration. If it is not, adjust the radiator as follows:

1) Adjust the position of the upper brackets.
2) Adjust the radiator position by changing the upper radiator hose position as shown.



b) Check that stud "A" protrudes less than 0.06in (1.5 mm) from the radiator mount. If it is more than 0.06 in. (1.5 mm), adjust the upper brackets for correct radiator position.

NOTE:
If the above procedures are not necessary, proceed to the next step.



5. Replace the radiator lower mount with the countermeasure part.


6. Replace No. 1 and No. 4 engine mounts with the countermeasure parts (refer to page B2-95 in the Workshop Manual for installation procedure). When installing the engine mounts, be careful not to bend the rubber.
7. After completion of the repair, if a rattle noise is heard from the top of the hood, adjust the hood lock.


WARRANTY INFORMATION

Warranty Type Code: A
Customer Comment Code: 83
Damage Code: 97
Part No. of Main Cause: B456 39 040C, B455 39 070D or B61N 15 202A
Operation No: YX0376RX - 1.0 Hr. (for all repairs) XX0331R2 - 0.4 Hr. (for checking and adjusting cooling fan harness, air conditioner pipe and radiator upper bracket)