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Changing Glow Plugs

Posted: Mon Aug 01, 2005 4:13 am
by n_dorphin
Hey All,
I am new to Diesels and will be replacing Glow Plugs this week.
Is it as simple as unscrewing the old ones and then fitting new units?
Does any special sealant or gaskets need to be replaced/used with plugs?
Cheers
Jason

Posted: Mon Aug 01, 2005 5:36 am
by De-lux
what type of truck you have?

i am in no way very mechanically minded, and i still managed to remove the glowies on my hilux.

its easy to do :cool:

Re: Changing Glow Plugs

Posted: Mon Aug 01, 2005 6:00 am
by Gribble
n_dorphin wrote:Hey All,
I am new to Diesels and will be replacing Glow Plugs this week.
Is it as simple as unscrewing the old ones and then fitting new units?
Does any special sealant or gaskets need to be replaced/used with plugs?
Cheers
Jason
Pretty much, like spark plugs they have an electrical source that needs to be disconected. And a little neverseize on their threads is a good idea.

Posted: Mon Aug 01, 2005 10:07 am
by Area54
If you have an older rig, be careful when you remove them, as the ends of the plug may have carbon deposits on them, and withdrawing them from the hole may dislodge the carbon deposit. Also some plugs may burn though, leaving a fragment of the burnt plug on the end, this fragment may also break off when removing the plug.

Before you remove the plug, degrease around the area to ensure no crud from the head/surrounding area falls down the hole when you remove the glow plug.

Posted: Mon Aug 01, 2005 11:22 am
by bazzle
You will most likely need a long reach socket and new copper crush washers.
Also do NOT bend fuel pipes as minature fragments come off the inside and will block new injectors.. Take them off in one assembly.
After refitting do NOT rev engine untill it has idled in smoothly as this can pump air in too fast and make new injectors stick.
When opening/removing pipes use 2 spanners, one to hold mating nut steady and one to loosen flange nut on end.

What sort of vehicle??

Bazzle

Posted: Mon Aug 01, 2005 11:32 am
by Gribble
bazzle wrote:You will most likely need a long reach socket and new copper crush washers.
Also do NOT bend fuel pipes as minature fragments come off the inside and will block new injectors.. Take them off in one assembly.
After refitting do NOT rev engine untill it has idled in smoothly as this can pump air in too fast and make new injectors stick.
When opening/removing pipes use 2 spanners, one to hold mating nut steady and one to loosen flange nut on end.

What sort of vehicle??

Bazzle
Glow plugs dude, glow plugs. :D

Posted: Mon Aug 01, 2005 11:35 am
by bazzle
Gribble wrote:
bazzle wrote:You will most likely need a long reach socket and new copper crush washers.
Also do NOT bend fuel pipes as minature fragments come off the inside and will block new injectors.. Take them off in one assembly.
After refitting do NOT rev engine untill it has idled in smoothly as this can pump air in too fast and make new injectors stick.
When opening/removing pipes use 2 spanners, one to hold mating nut steady and one to loosen flange nut on end.

What sort of vehicle??

Bazzle
Glow plugs dude, glow plugs. :D
Ha Ha AH

Fu**ed that up didnt I :roll:

oh well, if he does Injectors next

Bazzle :oops: :oops: :oops: :oops: :P

Posted: Mon Aug 01, 2005 1:08 pm
by Modified Toy
just make sure the new glow plugs are the same voltage as the old ones if the new ones are less than the old ones you will burn them out quick!

Posted: Mon Aug 01, 2005 4:45 pm
by n_dorphin
Cheers Guys,
It in an 89 Pajero SWB 2.5TD. (91,000Klms)
I tried testing the unit individually in the head after removing connecting wires from each glow plug and could not find a difference in resistance with a multi meter. They all read 0.2. How do I locate faulty glow plug?
Thanks
Jason

Posted: Mon Aug 01, 2005 5:42 pm
by bad_religion_au
2 tips i was given,

1. don't cross thread them, it's easy to do, but hard to reverse the problem

2. use a small amount of copper antisease stuff

Posted: Mon Aug 01, 2005 9:48 pm
by n_dorphin
Also I read in a post that I can not find again about a good diesel workshop in Rocklea.
Any one what its called?
Jason

Posted: Tue Aug 02, 2005 3:48 am
by crokie83
probably highway diesel
www.highwaydiesel.com.au

Posted: Tue Aug 02, 2005 5:46 am
by bazzle
n_dorphin wrote:Cheers Guys,
It in an 89 Pajero SWB 2.5TD. (91,000Klms)
I tried testing the unit individually in the head after removing connecting wires from each glow plug and could not find a difference in resistance with a multi meter. They all read 0.2. How do I locate faulty glow plug?
Thanks
Jason
All sound good to me..

What makes you think one is faulty??

Bazzle

Posted: Tue Aug 02, 2005 11:21 am
by n_dorphin
Bazzle,
When starting in cold weather it runs very rough for a minute and blows heaps of smoke. It clears up once running a for a bit and only happens on cold starts.
Jason

Posted: Tue Aug 02, 2005 11:50 am
by bad_religion_au
sounds like a natural diesel to me...

all a glow plug does is get enough heat into the head to allow combustion on cold starts... but if the engine is completely cold it'l overfuel and blow a bit of smoke... no harm no foul

if your plugs read ok, and the glowplug timer goes off in a reasonable amount of time i'd say their right

Posted: Tue Aug 02, 2005 12:22 pm
by Shadow
Wait a good 10 seconds before hitting the started and see if it makes a difference.

Do the pajero's run the glowplugs after start? the toyota's do (or the 2H does anyway). perhaps if the engine is running rough the pajero motor does not run the glow plugs after motor start (while its still cold), or perhaps the glow plug control system is not working correctly.

the glow plugs generally only run if the temperature requires it, perhaps whatever it uses to measure the temperature is malfunctioning?

if all your glow plugs are measuring consistently, it sounds like it could be a problem with another part of the pre-heat system.

Posted: Tue Aug 02, 2005 12:22 pm
by Slayer
bad_religion_au wrote:sounds like a natural diesel to me...

all a glow plug does is get enough heat into the head to allow combustion on cold starts... but if the engine is completely cold it'l overfuel and blow a bit of smoke... no harm no foul

if your plugs read ok, and the glowplug timer goes off in a reasonable amount of time i'd say their right
shouldnt really be "normal" for a deisel.. start mine every mornin in minus temps and it doesnt blow smoke, run rough or anythin.
sounds to me like u could have 1 crook glow plug meanin u arnt gettin any fire in 1 pot for a little while.. they are cheep to replace so it cant hurt to try...


duno about on your truck, or this dudes truck, but on hiluxes the timer light and the glowplug realy are seperate, the light goes off after like 10 seconds even if its minus 10, but the glow plugs will continue working for a few minutes...

Posted: Tue Aug 02, 2005 1:47 pm
by bad_religion_au
yeah i realised this after i posted... my experience is with an old H diesel, that didn't have a glowplug timer (you held the key backwards for them to warm, once released the glowplugs stopped heating)...

so for the fancy timed ones, possibly there is a problem... me and my big mouth

Posted: Tue Aug 02, 2005 2:01 pm
by Shadow
the toyota glow plugs operate at 10-12 volts for a maximum of about 15 seconds where they fall back to a lower voltage to stop them burning out

the toyota glow system (on a 2H anyway) will continue to glow at the reduced voltage until the engine is up to temperature. (2 minutes?)

so yes if they glow plugs are only working for 10 seconds and then switching off, the glow plugs could be faulty

put a multimetre on the glow plugs to emasure the voltage present at the glow plugs.

what is it before ignition? what is it after 10 seconds? what is it after motor start? when do they turn off?

I have no idea how a pajero pre-heating system works, but if the plugs are not on for long enoughi would say there is a problem with the control system, not the plugs.