Engine - Timing Chain Noise

Classification:
EM98-002a

Reference:
NTB98-055a

Date:
November 15, 1998

1993-98 ALTIMA TIMING CHAIN NOISE

This amended version of NTB98-055 contains updated warranty information.
Please discard any paper copies of NTB98-055.

APPLIED VEHICLES:
1993-97 Altima (U13)
1998 Altima (L30)

APPLIED VIN:
Vehicles built before 1N4DL01D0WC150648

APPLIED DATE:
Vehicles built before September 29, 1997

SERVICE INFORMATION

If a 1993-98 Altima exhibits excessive timing chain noise, the cause may be a broken tension-side timing chain guide on the lower timing chain. A new, metal-backed tension-side timing chain guide is available to resolve this incident.





For any reason whenever this guide is replaced, use the new countermeasure parts listed in Parts Information. The new guide along with the two bolts that secure it must be installed as a set (see Figure 1).

SERVICE PROCEDURE

Diagnosis

1. To isolate the noise, use a stethoscope or similar tool and listen at the front cover area.

A. If the noise is coming from the upper chain area, repair as necessary before proceeding.

B. If the noise is coming from the lower chain area, proceed to Lower Timing Chain Guide Replacement below.

IMPORTANT:
The two chain guides for the upper timing chain have been deleted. Remove and discard the two chain guides and bolts during any service to the timing chain (see Figure 1).

Lower Timing Chain Guide Replacement

1. Refer to NTB95-058c for the front cover replacement procedure. You do not need to remove the cylinder head or timing chain to install a new lower chain guide.

2. After performing steps 1 through 33 of the Removal of Front Cover from NTB95-058c, perform the following steps:

A. Remove the two bolts that secure the tension-side guide to the cylinder block and remove the guide.

B. Install the new guide with the two new bolts.

C. Before reassembly, perform the following inspection and make repairs as necessary:

1) Inspect the slack side chain guide for excessive wear.

2) To confirm the tensioner oil supply passage in the cylinder head is clear and not blocked by any debris, remove the tensioner, remove the oil filter and use compressed air to blow from the oil filter port forward through the tensioner feed hole.





3) Inspect the chain for cracks or excessive wear at the roller links (see Figure 2).

4) If the chain is replaced, spin the idler by hand to feel for roughness or play, and to listen for noise.

3. Go to the NTB95-058c Installation step 1 to complete the reassembly. Use a new O-ring seat from the Parts Information in NTB95-058c.

PARTS INFORMATION

DESCRIPTION PART NUMBER QUANTITY

Guide, chain, tension side 13085-1E4O1 1
Bolt, hex 13075-40F20 2

CLAIMS INFORMATION





Submit a Primary Failed Part (PP) line using the claim coding shown.