B002/94 HLA NOISE

Note: This bulletin supersedes the following TSB(s): B008/93 B011/91. Please update your records accordingly.

APPLICABLE MODELS/VINS

323 (GTX, 4WD)

1988 - Vehicles with a VIN of JM1BF234*J0100001 through JM1BG234*J0199999

1989 - Vehicles with a VIN of JM1BF234*K0200001 through JM1BG234*K0299999

MIATA

1990 - Vehicles with a VIN of JM1NA351*L0100001 through JM1NA351*L0199999

1991 - Vehicles with a VIN of JM1NA351*M0200001 through JM1NA351*M0299999

1992 - Vehicles with a VIN of JM1NA351*N0300001 through JM1NA351*N0399999

1993 - Vehicles with a VIN of JM1NA351*P0400001 through JM1NA351*P0423272

Protege (with DOHC)

1990 - Vehicles with a VIN of JM1BG224*L0100001 through JM1BG234*L0199999

1991 - Vehicles with a VIN of JM1BG224*M0200001 through JM1BG234*M0399999

1992 - Vehicles with a VIN of JM1BG224*N0400001 through JM1BG234*N0599999

1993 - Vehicles with a VIN of JM1BG224*P0600001 through JM1BG234*P0654718

NOTE: The asterisk (*) in the VIN range can be any number (0 through 9) or "X".

DESCRIPTION

A noise at the top of the engine that occurs several times faster than crank shaft rotation may be caused by restricted oil flow through the hydraulic lash adjusters (HLA's).

The noise is most common after cold engine starts or when returning to idle after highway driving (high speed). To correct the noise condition, HLA's have been modified to increase oil circulation.

If a customer complains of HLA noise and the vehicle is within the VIN range above, follow the repair procedure in this bulletin.

NOTE: If the HLA's require replacement, inform the customer that maintaining regular oil changes according to the scheduled maintenance will help prevent this noise from returning.

REPAIR PROCEDURES*

1. Check engine oil level. If the level is below "L", add oil.

2. Start the engine and verify the HLA noise. If the noise is not present, change the engine oil and inform the customer that regular oil changes will help prevent the noise from returning. If the noise is present, proceed to step 3.

3. If noise is present, increase the RPM to 2000 - 3000 for 2 minutes. Return to idle and check again for HLA noise. If noise is still present, increase the RPM to 2000 - 3000 for 1 0 minutes. Return to idle and check again for HLA noise. If noise is still present, proceed to step 4.

   NOTE: Monitor engine coolant temperature to avoid overheating during step 3.

4. Perform engine carbon cleaning as described in Service Bulletin Category B, #004/93.

5. If noise is still present, remove the rocker arm assembly covers and check the for excessive clearance between the cam shaft and the HLA.

   NOTE: HLA must not be in a compressed position. Turn the cam slowly to avoid air entering the HLA.

6. If 0.15mm or more can be inserted between the cam shaft and the HLA, replace the HLA.

   

PARTS INFORMATION

Part Number	Description	Interchangeability	Usage
New				Old
KL01 12 101B	B660 12 101	Hydraulic Lash Adjuster	(The new part can be used in place of the old part but the old part can not be used in place of the new part.)	Mass Production Part
KL01 12 101B	B6Y1 12 101	Hydraulic Lash Adjuster	(The old part and the new part are fully interchangeable.)	Service Countermeasure Part

WARRANTY INFORMATION *

*(Applies To Vehicles Covered Under Normal Warranty)

Warranty Type:

A

Customer Comment Code:

82

Damage Code:

99

Part Number Main Cause:

KL01 12 101B

Quantity:

As Necessary

Operation Number/Labor Hours:

B0410BRX/3.0Hrs.(MX-5),
B0410CRX/2.8Hrs. (Protege)

NOTE: Refer to Service Bulletin Cat. B #004/93 for warranty information on carbon cleaning and oil change.