Engine - Noise From VTC Camshaft Sprockets

Classification:
EM95-03

Section:
Engine Mechanical

Reference:
Technical Bulletin NTB95-022

Date:
February 8, 1995

1992-94 MAXIMA VE30DE ENGINE NOISE (VTC) REPAIR

APPLIED MODELS:
1992-1994 MY Maxima (J30) SE with VE30DE engine

SERVICE INFORMATION

Some VE30DE engines installed in '92-'94 MY SE Maxima vehicles may exhibit noise from the VTC (Variable Timing Control) intake camshaft sprockets under certain engine operating conditions.

Use the following procedure to diagnose and repair these vehicles.

DIAGNOSIS




1. Disconnect the VTC Solenoid connectors from both cylinder heads. See diagram for location.

2. Connect CONSULT (key "On") and access "Valve Timing Solenoid Test" under "ACTIVE TEST" (found under "ENGINE"). Touch "ON" at the bottom of the CONSULT screen.

3. Start the engine and while the noise is occurring, connect the VTC solenoids one at a time. Note if the noise decreases when one or both VTCs are reconnected.

4. If one or both VTC's are noisy, remove the VTC intake camshaft sprocket(s) for repair. The VTC's should be repaired using this Bulletin. Do not replace the VTCs.

NOTE:
If the noise is not reduced or eliminated, see Technical Bulletin NTB93-189 (EM93-005) titled "DIAGNOSING AND REPAIRING TOP END NOISE IN VE30DE ENGINES" dated December 21, 1993. If further assistance is required, contact TECHLINE.

VTC REPAIR PROCEDURE




This procedure involves repair (not replacement) of the VTC intake camshaft sprockets.

Special Service Tool kit (J-41471) and a press capable of generating one (1) Ton (2000 lbs.) force is required for this procedure. One tool kit will be shipped to each Nissan dealer in January 1995 free of charge. Dealers may order additional J-41471 tools from Kent-Moore (800-NMC-2001).

DISASSEMBLY OF THE VTC




1. Scribe or mark a line across the face of the VTC body and shaft (camshaft end), so that the parts can be re-assembled with the same alignment.




2. Place the VTC in the press using the 2" diameter by 1" thick round stock with the open side toward the sprocket (camshaft) end of the VTC, and the 20 mm steel ball in the bolt hole at the opposite (cover) end of the VTC (see illustration).

3. Press gradually until the cover comes loose. Discard the cover with seal ring and O-ring.




4. Scribe or mark a line across the face of the VTC body, gear, and shaft (cover end) so that the parts can be re-assembled with the same alignment. Misalignment of the parts during re-assembly will result in noise.

Use hand pressure for steps 5-7

5. With one hand, hold the VTC body and press out the shaft and gear with the thumb of the other hand. Push the gear and shaft out of the sprocket end of the VTC body. Be careful not to drop the parts as they are under spring pressure. Discard the spring.

ASSEMBLY OF THE VTC




6. Insert the gear into the VTC body, ensuring that the scribe marks from step 3 line up.

7. Install the C/M spring from the repair kit into the gear.

8. Insert the shaft into the gear (already installed into the VTC body), ensuring that the scribe marks on the VTC body, gear, and shaft from step 3 line up. Use caution since the parts are under spring pressure. If the scribe lines cannot be seen, discard the VTC.

Using hand pressure, press the body down onto the shaft and gear. The parts will stay together when the scribed surfaces are approximately flush.




9. Install the new VTC cover, seal ring, and O-ring onto the VTC body (see illustration). Place these parts into the press with the piece of 1-13/16" diameter by 5/8" round stock in the sprocket (camshaft) end of the VTC body and the 1-3/16" diameter by 1-1/8" machined round stock in the bolt hole at the cover end of the VTC. Place the 20 mm steel ball in the top of 1 3/16" diameter by 1-1/8" machined round stock in the bolt hole. See illustration.

10. Press gradually with approximately 1 ton (2000 lbs.) force until the cover is installed onto the VTC body. Confirm that the shaft protrudes 0.05-0.20 mm above the cover, indicating that the cover is pressed on completely.

11. Reinstall the VTC intake camshaft sprocket(s) using the service manual procedure. If noise still occurs, contact TECHLINE.




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