Glow plugs?

[jn_inciong]

hi, i am new to the forum, hope anybody can help me understand more about my problem.

i have a 98 pajero with 4m40 engine, 6 months ago i replaced the 3 of my glow plugs because its faulty. just today, 3 of my glow plugs are busted again. i believe glow plugs have a lifespan of more than a yr. so tested the connection....from the glow plug relay...when i turned on the ignition..there was a signal for about 15 seconds or so....after starting the engine....there was again a signal of around 14v...and would go off after 5 mins... Is is normal to do this?! this means that after starting the engine...the glow plugs are still on for another 5 mins!? i think this is the reason why my plugs busted very soon.

Hope anybody can enlighten me on this issue.

Thank you.

[kimpOy]

there are glow plugs and there are cheap glow plugs...
invest in original glow plugs jn_inciong, sulit in the long run...

and while you're at it, check your starter and its carbon, your batt terminal and its cable

[OTEP]

i believe glow plugs have a lifespan of more than a yr. so tested the connection

Hindi pa ko nagpapalit ng GP's since the '96 Pajero was acquired in '01.

I'm just not sure how long power is supplied to the GP's.

[slamtaz]

*jn_inciong: i lifted up the foregoing for your perusal...

Glow Plug Service

In troubleshooting glow plug fault codes/check engine lights, the very first step is to unplug the glow plug harness from all of the glow plugs and to test resistance of all four glow plugs with a volt/ohmmeter. One probe of the meter should be put onto the tip of the glow plug and the other probe should be grounded to the cylinder head. All resistance values for the four glow plugs should be very close to the same. If one of the plugs reads more than .2 different from the others then it is likely bad. If all four glow plugs read the same or close to the same resistance then the fault code can usually be remedied by either replacing the glow plug harness or by squeezing gently the side of the glow plug harness (with pliers) where the female metal connector is inside the harness. This will tighten up the electrical connection between the glow plugs and harness. A poor or dirty connection between the glow plugs and the glow plug harness is probably the most common cause of a glow plug fault in our opinion. Glow plug relays are the least common cause of a check engine light and should be the last step in remedying a glow plug fault code.

hope this helps...

edit:

Hindi pa ko nagpapalit ng GP's since the '96 Pajero was acquired in '01.

I'm just not sure how long power is supplied to the GP's.

iirc, glow plugs are there only for starting/ignition purposes. the lifespan of a good glow plug should be pretty long when properly installed/maintained..

[Dieseldude]

From my experience, Mitsubishi 4M40 glow plug failures are caused by the following:

1) Faulty injection pump / hard starting: Requires long and repetitive cranking periods. Glow plugs are electrically energized while cranking. Glow plug life is shortened due to the prolonged heating time.

2) Poor quality replacement glow plugs. Buy original plugs from Mitsubishi.

3) Use of mismatched glow plugs. Mitsubishi has various part numbers for their glow plugs. Make sure you are buying the correct plug for your specific engine model.