Amsoil FAQ/Technical Bulletin on MAF contamination
#1
Amsoil FAQ/Technical Bulletin on MAF contamination
I don't know if you guys can see this or not. It's in the dealer zone, but it may be accessible from this link. Give it a try:
http://www.amsoil.com/dealer/techser...af_sensors.pdf
It describes MAF technology as it relates to self-cleaning, burnout issues, and oil contamination. I use an Amsoil filter myself, so I found it interesting.
http://www.amsoil.com/dealer/techser...af_sensors.pdf
It describes MAF technology as it relates to self-cleaning, burnout issues, and oil contamination. I use an Amsoil filter myself, so I found it interesting.
#9
Well, here's the text of it, from the acrobat document but I haven't formatted it from it's original 2 column format with imbedded illustrations, so it's a bit coarse:
AMSOIL INC., AMSOIL Bldg., Superior, WI 54880 (715) 392-7101 © Copyright 2003
DESCRIPTION
The mass airflow sensor (MAF) is a common engine component
on nearly all electronically fuel injected engines. It
is an electronic unit that measures the volume of air being
drawn into the engine and allows the engine computer to
calculate how long the fuel injectors need to be open to
maintain the correct fuel to air ratio under all operating
conditions. MAF sensors have no moving parts. Instead,
they use a heated sensing element to measure air flow.
There are two types of MAF sensors:
hot-film and hot-wire. In a hot-film
MAF, a foil grid is heated about 170
degrees F above ambient air temperature.
In a hot-wire MAF, a platinum
wire is heated approximately 212
degrees F above the incoming air temperature.
As air flows past the sensor element, it cools
the wire and increases the current
needed to keep the element at its operating
temperature.
The wire element is very sensitive to
any form of contamination, including
oil vapor from PVC systems, dirt, silicon,
moisture, etc. To eliminate any deposits on the wire,
it undergoes a burn off cycle every time the engine is
switched off. Approximately four to five seconds after the
engine is stopped, the wire is heated to 1,000 degrees C for
about one second through the use of a relay switch. Due
to the high temperature and the presence of oxygen in the
air, a reaction called wire erosion occurs. Eventually, the
erosion causes the MAF output voltage to be skewed and
will not allow the engine to run correctly. As with the filament
in a light bulb, the sensor wire within a MAF will
eventually fail and require its replacement.
In some instances contamination becomes substantial
enough to produce skewed information, causing the sensor
to over-estimate air flow at idle and under-estimate air
flow at higher air flow volumes. The symptoms of an
improperly functioning MAF include hard starting, engine
stall, pinging, lack of power, jerking, hesitation/surge on
acceleration and high emissions.
Besides contamination, there are other factors that cause
the MAF to fail, including the burn off relay not functioning,
shorting of the MAF harness, overheating of the hot
wire assembly due to grounding, engine backfire, cracking
of MAF housing, dead spot in the throttle position sensor,
vibration or shock, sensor wire fatigue and physical damage
due to poor handling or physically attempting to clean
the wire element.
Because of the many possible reasons for a MAF failure,
the exact cause is often incorrectly diagnosed. Available
diagnostic tools can only indicate that a MAF is not functioning
and provide virtually no information as to why it
failed. All too often, the engine’s air filter is blamed for
the MAF failure, whether it be a conventional pleated
paper filter or an oil wetted foam filter such as the
AMSOIL Air Filter. However, the likelihood of an air filter
causing MAF failure is minimal.
AMSOIL Air Filters will not cause MAF failures for the
following reasons:
• Filter oil is tackified, preventing oil migration.
• MAF sensors are designed to function in the presence
of contaminates.
• Filters are centrifuged to insure the proper amount of
oil is in the filter upon installation.
A rare exception could be if, during field servicing, the
AMSOIL Air Filter was grossly over-oiled or re-oiled
using the wrong (non-tackified) oil.
AMSOIL Air Filters can be used with confidence in applications
utilizing MAF sensors.
TSB: FL-2003-09-01
Date: 8/29/2003
Product Description: Air Filters
Subject: Mass Airflow Sensors
Submitted By: DW Approved By: DRA Approval Date: 9/08/03
Distribution: Internal X All
Page 1 of 1
Technical Service Bulletin
AMSOIL INC., AMSOIL Bldg., Superior, WI 54880 (715) 392-7101 © Copyright 2003
DESCRIPTION
The mass airflow sensor (MAF) is a common engine component
on nearly all electronically fuel injected engines. It
is an electronic unit that measures the volume of air being
drawn into the engine and allows the engine computer to
calculate how long the fuel injectors need to be open to
maintain the correct fuel to air ratio under all operating
conditions. MAF sensors have no moving parts. Instead,
they use a heated sensing element to measure air flow.
There are two types of MAF sensors:
hot-film and hot-wire. In a hot-film
MAF, a foil grid is heated about 170
degrees F above ambient air temperature.
In a hot-wire MAF, a platinum
wire is heated approximately 212
degrees F above the incoming air temperature.
As air flows past the sensor element, it cools
the wire and increases the current
needed to keep the element at its operating
temperature.
The wire element is very sensitive to
any form of contamination, including
oil vapor from PVC systems, dirt, silicon,
moisture, etc. To eliminate any deposits on the wire,
it undergoes a burn off cycle every time the engine is
switched off. Approximately four to five seconds after the
engine is stopped, the wire is heated to 1,000 degrees C for
about one second through the use of a relay switch. Due
to the high temperature and the presence of oxygen in the
air, a reaction called wire erosion occurs. Eventually, the
erosion causes the MAF output voltage to be skewed and
will not allow the engine to run correctly. As with the filament
in a light bulb, the sensor wire within a MAF will
eventually fail and require its replacement.
In some instances contamination becomes substantial
enough to produce skewed information, causing the sensor
to over-estimate air flow at idle and under-estimate air
flow at higher air flow volumes. The symptoms of an
improperly functioning MAF include hard starting, engine
stall, pinging, lack of power, jerking, hesitation/surge on
acceleration and high emissions.
Besides contamination, there are other factors that cause
the MAF to fail, including the burn off relay not functioning,
shorting of the MAF harness, overheating of the hot
wire assembly due to grounding, engine backfire, cracking
of MAF housing, dead spot in the throttle position sensor,
vibration or shock, sensor wire fatigue and physical damage
due to poor handling or physically attempting to clean
the wire element.
Because of the many possible reasons for a MAF failure,
the exact cause is often incorrectly diagnosed. Available
diagnostic tools can only indicate that a MAF is not functioning
and provide virtually no information as to why it
failed. All too often, the engine’s air filter is blamed for
the MAF failure, whether it be a conventional pleated
paper filter or an oil wetted foam filter such as the
AMSOIL Air Filter. However, the likelihood of an air filter
causing MAF failure is minimal.
AMSOIL Air Filters will not cause MAF failures for the
following reasons:
• Filter oil is tackified, preventing oil migration.
• MAF sensors are designed to function in the presence
of contaminates.
• Filters are centrifuged to insure the proper amount of
oil is in the filter upon installation.
A rare exception could be if, during field servicing, the
AMSOIL Air Filter was grossly over-oiled or re-oiled
using the wrong (non-tackified) oil.
AMSOIL Air Filters can be used with confidence in applications
utilizing MAF sensors.
TSB: FL-2003-09-01
Date: 8/29/2003
Product Description: Air Filters
Subject: Mass Airflow Sensors
Submitted By: DW Approved By: DRA Approval Date: 9/08/03
Distribution: Internal X All
Page 1 of 1
Technical Service Bulletin
#15
Originally Posted by n3elz
I'm using it. They have some new types out. I have the 80w90 Series 2000 fluid in my LS diff with no additives needed. Good stuff.
#16
#19
#21
I'm not a dealer now, only preferred customer (same pricing, but I can't sell it). For now, get in touch with WholesaleMN.com (Charles) here on the board. Yes, his user name has .com in it, lol. He is set up and ready to go. I will be setting up a dealership in 2005. When I do that, I'll be happy to sell it! Certainly, I'll still be using it!
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