glow plugs
#5
Plugs are very seldom cause of failure:
Heater element with folds and hollows
Causes
Open circuit coil due to
•Operation at too high voltage, e.g. on jump starting
•Excessively long current feed due to sticky relay
•Incorrect post-heating with the engine running
•Glow plugs that can be post-heated not used (type GN)
Rectification
•Only jump start with 12 V electrical systems
•Check the pre-heating system, replace automatic pre-heating relay
•Fit glow plugs that can be post-heated
Heater element melted or burnt away
Causes &
Overheating of the heater element due to:
•Injection starting too early
•Coked or worn nozzles
•Dripping nozzles
•Engine damage e.g. due to piston seizing, valve damage, etc
•Seized piston ring
Rectification
•Adjust injection timing exactly
•Replace complete injector
Connecting bolt broken off, hex head damaged
Causes
•Connecting bolt broken off: the connecting nut was over tightened
•Damaged hex head: usage of inappropriate tool; due to deformation the plug has a short circuit from the housing to the circular nut.
Rectification
•Use a torque wrench to tighten the connecting nut, tightening torque for M 4 thread: max. 2 Nm, for M5 thread max. 3 Nm; do not oil or grease thread.
•Tighten plug with suitable torque wrench; observe stipulated tightening torque exactly (can also be obtained from the vehicle manufacturer's information). Do not oil or grease thread.
Tip of heater element damaged
Causes
Overheating of the heater element due to
•Injection starting too early resulting in the heater element and heater coil being overheated; the heater coil becomes brittle and breaks.
•Annular gap between plug housing and heater element reduced, as a result too much heat flows from the heater element, the regulator coil remains cold and permits too much current to flow through the heater coil that then overheats.
Rectification
•Check injection system, adjust injection timing exactly.
•On fitting a glow plug, it is imperative that the tightening torque specified by the manufacturer is observed.
Heater element with folds and hollows
Causes
Open circuit coil due to
•Operation at too high voltage, e.g. on jump starting
•Excessively long current feed due to sticky relay
•Incorrect post-heating with the engine running
•Glow plugs that can be post-heated not used (type GN)
Rectification
•Only jump start with 12 V electrical systems
•Check the pre-heating system, replace automatic pre-heating relay
•Fit glow plugs that can be post-heated
Heater element melted or burnt away
Causes &
Overheating of the heater element due to:
•Injection starting too early
•Coked or worn nozzles
•Dripping nozzles
•Engine damage e.g. due to piston seizing, valve damage, etc
•Seized piston ring
Rectification
•Adjust injection timing exactly
•Replace complete injector
Connecting bolt broken off, hex head damaged
Causes
•Connecting bolt broken off: the connecting nut was over tightened
•Damaged hex head: usage of inappropriate tool; due to deformation the plug has a short circuit from the housing to the circular nut.
Rectification
•Use a torque wrench to tighten the connecting nut, tightening torque for M 4 thread: max. 2 Nm, for M5 thread max. 3 Nm; do not oil or grease thread.
•Tighten plug with suitable torque wrench; observe stipulated tightening torque exactly (can also be obtained from the vehicle manufacturer's information). Do not oil or grease thread.
Tip of heater element damaged
Causes
Overheating of the heater element due to
•Injection starting too early resulting in the heater element and heater coil being overheated; the heater coil becomes brittle and breaks.
•Annular gap between plug housing and heater element reduced, as a result too much heat flows from the heater element, the regulator coil remains cold and permits too much current to flow through the heater coil that then overheats.
Rectification
•Check injection system, adjust injection timing exactly.
•On fitting a glow plug, it is imperative that the tightening torque specified by the manufacturer is observed.
Last edited by Deezel Stink3r; 01-21-2010 at 05:05 PM.
#6
yes, the 6.9 glow plug system is a bad design. thus the reason alot of us switch over the the 7.3 idi glow plug system.
the stock 6.9 system will overheat the plugs,(bosch,acdelco) and cause them to swell.
motorcraft, buer, and ih rarely swell when left on to long.
wellmans are a different game, they are dual coil, thus taking a little longer to warm up, so not getting as hot witht he stock setup.
the stock 6.9 system will overheat the plugs,(bosch,acdelco) and cause them to swell.
motorcraft, buer, and ih rarely swell when left on to long.
wellmans are a different game, they are dual coil, thus taking a little longer to warm up, so not getting as hot witht he stock setup.
#8
#10
Thread
Thread Starter
Forum
Replies
Last Post
GT_Eleanor
Ford 83-94 6.9 and 7.3L General
0
09-14-2015 10:52 AM