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Why glow plugs are needed for diesel
engines?
æ
to reduce smoke emission
æ
to heat up the incoming air
æ
to reduce engine noise and vibrations
æ
to improve drivability from cold
Pre-heating phase
æ
The pre-heating system supplies the
additional heat energy which is required
for a cold start.
æ
Just before starting the engine a
voltage is applied to the terminal of the
glow plug and the current flows through
the coils of wire inside the heater tube.
This heats up rapidly, the heat energy
being transferred to the protective sheath
causing it to glow.
æ
The time taken to reach sufficient
temperature where stable combustion
is attainable varies with different engine
designs.
Post-heating phase
æ
The glow plugs continues glowing after
start-up to reduce the amount of white
or blue smoke produced. As well as to
eliminate any starting problems at low
temperatures. The post-heating phase is
determinate on the engine temperature, as
a cold diesel engine produce more noise
and pollutant emissions.
About the glow plugs
Important on replacement: need to
observe the right tightening torque for
glow plugs and power connection nuts!
When replacing glow plugs, we
recommend you to pay special
attention on these main aspects:
u
Use the right wrench for the glow plug
and terminal
v
Take care that dirt around the hole for
the plug could not fall into the cylinder
w
Make sure that the glow plug is
correctly inline with the thread of the
cylinder head
x
The glow plug must be tightened to the
correct torque
y
The power connection nuts need to
be tightened to the correct tightening
torque.
The glow plug could be damaged by
using oversize torque. This could result in
irreparable damage to the plug, as well as
to the damage on the engine.
1. Fitting a glow plug with a torque
wrench:
Please observe vehicle manufacturer’s
specifications. Do not grease or oil
threads!
Caution – observe maximum torque
settings:
M8 threads:
8-14 Nm
M10 threads: 15-18 Nm
M12 threads: 20-25 Nm
2. Fitting a glow plug without a torque
wrench:
Screw the glow plug into the cylinder first
by hand. Then use a suitable ring spanner
and tighten the glow plug for approx. 30
0
.
Do not oil or grease the thread.
3. Tightening the power connection nut:
The maximum torque setting for the power
connection nuts must not exceed the
following values:
M4 threads max. 2 Nm
M5 threads max. 4 Nm
If glow plugs have pin connections, please
check also these for corrosion.
The correct way to replace glow plugs
Product Warranty
All automotive parts are in compliance with EU warranty conditions. This
warranty is limited to the defects in materials or unsatisfied performances of
the products as supplied by the manufacturer.
This warranty does not cover parts that fail as a result of improper installation,
misuse, abuse or the failure of another part. Parts modified for use or installed
for use other than their original design and application have no warranty.