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Handy121 Newbie
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Posted: Apr 05 2015 at 9:26am | IP Logged
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Posted: Jul 16 2014 at 11:13am | IP Logged
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frontierguy wrote:
Not using hi-test gas will also raise havoc with the SC.
If the knock sensor is defective it usually retards the
timing, thus putting the SC in failsafe mode. Hence the
noise.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.
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Dear sir, I am trying to understand the
function of the bypass solenoid. If the ECM is putting the solenoid in
bypass mode is it adding electricity to the solenoid or not? What is
the normal operation of this solenoid? Why two vacuum sources? Also can
you explain the bypass valve? When it is closed the supercharger is
producing boost. Is that in the up position or down position, referring
to the linkage at the bypass actuator? I installed a boost gauge
and I see at idle -0.6 or -0.7. The gauge is connected to the FPR vacuum line. When I accelerate it goes to +0.1. Up or down when bypassing air.
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__________________ 2001 Nissan Frontier 4x4 Super Charged V6 145,000 miles
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frontierguy Senior Member
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Master Mechanic
Joined: May 20 2008
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Location: U.S. - Pennsylvania
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Posted: Apr 05 2015 at 5:42pm | IP Logged
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Not real sure of the way it operates. I do not have access
to info @ home. Are you having any particular problems or
just curious about the boost gauge?
__________________
'10 Altima SL
Traded 08 Frontier for 16 Frontier SV CC Long box, quite an upgrade. I do miss the 6 speed and Dynomax ex.
Nissan Technician 25 + years
2011 John Deere X720SE
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Handy121 Newbie
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Posted: Apr 05 2015 at 9:02pm | IP Logged
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Is the bypass valve on the supercharger closed when the actuator is up? From what I can read when the bypass solenoid is on, no vacuum is sent to the actuator from the solenoid. If off the vacuum from the breather would pull it down opening the supercharger bypass valve. If on, this causes the upper part of the actuator to receive vacuum from the supercharger manifold on top. That vacuum is always available pulling the actuator up which is closing the supercharger bypass valve. So normally unless there is a problem that usually throws a code, a heavy load or high RPMs the actuator linkage is in the up position which is a closed supercharger bypass valve. Such is my case. I don't understand why my boost gauge only gos from -6 to +1 or 2. a boost of only 7. I hear of boost in the range of 10 to 18. So, I want to see of my SC is failing it's job. This engine has 165,000 on it.
Second, What is the purpose of the vacuum line running from the back base of the supercharger next to the FPR vacuum line, to the back of the bypass solenoid? This vacuum is connected to the breather vacuum when the solenoid is on. A straight thru kind of thing vacuum against vacuum. Confusing.
More confusing is the vacuum layout in the shop manual showing two bypass solenoids on is 14956V one is 14956VA. The VA looks like mine but the middle vacuum connection is not plotted. The 14956v shows it going to the lower part of the actuator to open the SCB.
Ultimately, I see no difference when I tie down the actuator with a nylon tie than I do when it is free and up, on the boost gauge. Nor is there any more power with it up or down. I just replaced the actuator from Nissan due to a lower vacuum actuator leak. Thanks for your reply.
__________________ 2001 Nissan Frontier 4x4 Super Charged V6 145,000 miles
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Handy121 Newbie
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Posted: Apr 05 2015 at 9:07pm | IP Logged
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Also I would add that I use HItest 91 and have checked the MAF none of which is a problem since the actuator is always up unless I unplug the bypass solenoid then it goes down. Sounds correct.
__________________ 2001 Nissan Frontier 4x4 Super Charged V6 145,000 miles
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frontierguy Senior Member
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Posted: Apr 06 2015 at 5:26pm | IP Logged
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Again, I have no info readily available here @ home nor in
my 60 yo brain.
__________________
'10 Altima SL
Traded 08 Frontier for 16 Frontier SV CC Long box, quite an upgrade. I do miss the 6 speed and Dynomax ex.
Nissan Technician 25 + years
2011 John Deere X720SE
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