“The common cause of top engine noise on this engine has been the intake camshaft sprockets themselves.”

Vehicle:
1992 through 1994 Nissan Maxima

Engine:
VE30DE

System:
Engine Mechanical

Symptom:
Top engine noise
This engine has a variable timing control (VTC) system. The intake camshafts are advanced by using oil pressure on the intake camshaft sprockets under certain conditions. Oil pressure to the sprockets is controlled by the VTC solenoids, and the solenoids in turn are controlled by the engine computer (PCM).

The common cause of top engine noise on this engine has been the intake camshaft sprockets themselves. The VTC solenoids are "off" when cam timing is not being advanced. When the VTC solenoids are turned "on" by the PCM, intake camshaft timing is advanced.

To determine if the noise is coming from the VTC sprockets, unplug the VTC solenoids and energize each solenoid. The power supply to the VTC solenoids is the red wire with black tracer (R/B), so jump the battery voltage supply to the solenoid that the R/B wire goes to. When the noise is present at idle, jump the other terminal of the VTC solenoid to ground. This is the yellow wire with green tracer going to it. This will energize or turn "on" the VTC solenoid and results in pressurizing the sprocket and advancing the cam timing.

Energize one VTC solenoid at a time to see if the noise decreases or goes away. Also energize both solenoids at the same time. Is the noise gone? If it is, a new spring assembly can be installed in the VTC sprocket to tighten it up and correct the problem. The sprocket needs to be pressed apart to replace this spring. Make sure to scribe a mark on the sprocket before pressing it apart so the sprocket can be reassembled in the same alignment, or a noise could result.

Other causes of top engine noise on these engines: timing chain tensioner noise, debris in an oil galley restricting oil to the VTC sprockets or chain tensioner, or from the hydraulic lifters themselves ... although the noise is seldom from the lifters.

Note: Nissan's TSB No. NTB95-022 addresses this issue.

Paul Kujawa is an IDENTIFIX Asian specialist. He is ASE master and L1 certified with 24 years of diagnostic and repair experience.

This information is provided by IDENTIFIX®. IDENTIFIX® resources cut diagnostic time and provide repair solutions that increase the shop's bottom line. From Repair-Trac pattern failure quick fixes, to Diagram-Online wiring diagrams by fax, to the Repair Hotline staffed by 32 master techs who specialize in diagnosing complex problems by phone or fax, IDENTIFIX® helps techicians fix more cars in less time. For more information on IDENTIFIX, call (800) 288-6210, 8 a.m. - 6 p.m. Central Time. www.identifix.com. © 2008 IDENTIFIX. All Rights Reserved. © 2001 IDENTIFIX. All Rights Reserved.

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