GP resistance

[iamdave0887]

i need to know the correct GP resistance for a good working glow plug. i did the test light check on the 4 i could get too easily and the light lit on all of them but i want to check correct resistance as turbine doc said i might have a glow plug issue when he heard my truck cold start.

 

[NVW]

I believe it's under 2 ohm's. 1-1.5 ohm's is better. Leo

 

[gmctd]

Correct resistance check is: connected directly to a fully charged battery: if it glows in the middle only in ~5secs, it's bad - if it glows from the middle to the tip in ~5secs, it's good - if it glows at the tip only in ~5secs, it's bad - no other checks acceptable, particularly in winter climes.................

 

[iamdave0887]

there's no way to check them without removing them from the truck?

 

[chrisk1500]

Dave - you can test them using the resistance method if you would like, but what jd is saying is that you need to pull them to see what they are actually doing when exposed to some power.....not all glowing is equal....

 

[corolla]

My new ACDelco's were ~1 Ohm.

 

[gonnasellit]

Checking resistance is pretty much useless. I've seen a number of plugs which would go open after heating up. I also had one check good with an ohmmeter in one of my old 5.7's which had lost it's tip! The method described by GMCTD is the only surefire way to test.

 

[Turbine Doc]

GMCTD is spot on with test Dave, resistance check on them will only tell you if the element has completely failed.

 

[iamdave0887]

grr.... figured it had to rain todayrrr:. i was gonna get out there and see if i have any bad ones but i hate working in the rain. last time i checked the glow plugs seemed to be in there pretty good. any tricks to getting them out of the truck without busting them? i'd say PB blaster or something similar as usual but figured i'd ask. i've busted the heads of of plenty of bolts on this truck thanks to its rhode island salt days before i owned it. the last thing i want to do is bust a glow plug off in the head.

 

[94K30]

grr.... figured it had to rain todayrrr:. i was gonna get out there and see if i have any bad ones but i hate working in the rain. last time i checked the glow plugs seemed to be in there pretty good. any tricks to getting them out of the truck without busting them? i'd say PB blaster or something similar as usual but figured i'd ask. i've busted the heads of of plenty of bolts on this truck thanks to its rhode island salt days before i owned it. the last thing i want to do is bust a glow plug off in the head.

Hi Dave, Use plenty of PB Blaster, and a 6 pt socket. If you run into one that is really in there, start the truck, run it around till hot, and do it then... they heat will help, too

 

[gmctd]

Correct: meter-test is only to see if any are open - they can read correct at ~ 0.8 to 1.2 ohms, but still not glow enuff to lite it off when ambient temps drop below 40deg - also can read correct and glow correct, but only way to know that is with the battery test