Engine - Supercharger Noise at Idle/Low Engine Power

Classification:
ECO4-011

Reference:
NTB04-083

Date:
July 14, 2004

2001-2004 FRONTIER AND XTERRA;
SUPERCHARGER NOISE AT IDLE AND LACK OF POWER

APPLIED VEHICLES:
2001 - 2004 Frontier (D22) equipped with supercharger.
2002 - 2004 Xterra (WD22) equipped with supercharger.

IF YOU CONFIRM:

^ The supercharger makes a rattle/grinding type noise at Idle, and

^ The engine has reduced power while driving.

ACTION:

a. Review the supercharger information in this bulletin.

b. If your incident is not caused by "park knock" as described in this bulletin:

^ Go to ASIST for further diagnostic information

NOTE:
DO NOT REPLACE THE SUPERCHARGER FOR A SPARK KNOCK INCIDENT.

SUPERCHARGER INFORMATION

Premium fuel is required

^ The Supercharged (VG33) V-6 engine used in the 2001-2004 D22 Frontier and the 2002-2004 WD22 Xterra requires Premium Fuel.

^ If premium fuel is not used, the engine may experience "park knock" during acceleration or under heavy loads.

^ If spark knock is detected by the "knock sensor", the ECM will put the supercharger into bypass (fail-safe) mode.

^ The supercharger will make a rattle/grinding type noise at idle when it is in "fail safe".

^ Also, the engine will have reduced power if driven in "fail safe".

Supercharger Bypass Valve

^ The bypass valve limits boost pressure from the supercharger when the system is in fail-safe.





^ In fail-safe, the internal bypass valve will remain mostly closed (see Figure 1).

^ After the key is turned OFF the ECM will reset and restore the boost solenoid function.

The bypass valve will function normally, and the rattle/grinding type noise will be eliminated.





Disclaimer