Testing glow plugs??
#1
11-02-2015, 10:27 AM
Testing glow plugs??
It is just hovering around freezing and my 97 , 6.5 doesn't like to start all of a sudden.
If I plug in the block heater all is fine, but this is just not right at these temps, even with 15/45 oil.
How do I check the glow plug relay and glow plugs? Normaly this truck is fine to -20C without being pluged in. The glow plug indicator light in the dash seems to indicate all is well, but all is not well.
Pluged in , or warm from running if fires up instantly. Cold , as in just at freezing temp, it is a Bas^7%$*d to start.
Pete
If I plug in the block heater all is fine, but this is just not right at these temps, even with 15/45 oil.
How do I check the glow plug relay and glow plugs? Normaly this truck is fine to -20C without being pluged in. The glow plug indicator light in the dash seems to indicate all is well, but all is not well.
Pluged in , or warm from running if fires up instantly. Cold , as in just at freezing temp, it is a Bas^7%$*d to start.
Pete
Last edited by petew; 11-02-2015 at 10:31 AM.
#2
11-12-2015, 07:44 AM
Diesel Enthusiast
I have run nothing but Amsoil 5w30 heavy duty diesel oil in my 6.5's since I got them.
In my experience, vehicles that have been run on synthetic oils last longer than dino engines. I run 20,000 mile oil changes with a bypass filter.
uSE A CONTINUITY tester / multi meter. unplug the glow plugs. Use the buzzer if your tester has one.
Put one lead to the spade connector and the other lead to ground. Your buzzer should be buzzing if the glow plugs are good.
I'd get a set of glow plugs before you start. Use high temp anti seize on the threads. I also use Kopr Kote on the spade connector. Sometimes they get a little stuck on the spades.
Use only AC Delco 60G or Bosch Duraterm glow plugs. None of the others have the same rep for performance or longevity.
Even if the glow plugs test good, I would remove them just to give the threads a fresh coat of anti seize.
You can test the glow plug wires while the glow plugs are all unhooked by testing from the controller to the spade connector at the end of the wire.
It helps to have an alligator clip on your tester lead>
If your glow plugs are good, you can test for voltage at one of the glow plugs.
Continuity doesn't always tell the whole story. if a wire is about broke, it may show continuity but not carry enough amps to do anything worth while.
raceday mechanic sells new glow plug wires if you find yourself in need. I believe somebody else makes glow plug wires up as well. Maybe check leroydiesel.com
In my experience, vehicles that have been run on synthetic oils last longer than dino engines. I run 20,000 mile oil changes with a bypass filter.
uSE A CONTINUITY tester / multi meter. unplug the glow plugs. Use the buzzer if your tester has one.
Put one lead to the spade connector and the other lead to ground. Your buzzer should be buzzing if the glow plugs are good.
I'd get a set of glow plugs before you start. Use high temp anti seize on the threads. I also use Kopr Kote on the spade connector. Sometimes they get a little stuck on the spades.
Use only AC Delco 60G or Bosch Duraterm glow plugs. None of the others have the same rep for performance or longevity.
Even if the glow plugs test good, I would remove them just to give the threads a fresh coat of anti seize.
You can test the glow plug wires while the glow plugs are all unhooked by testing from the controller to the spade connector at the end of the wire.
It helps to have an alligator clip on your tester lead>
If your glow plugs are good, you can test for voltage at one of the glow plugs.
Continuity doesn't always tell the whole story. if a wire is about broke, it may show continuity but not carry enough amps to do anything worth while.
raceday mechanic sells new glow plug wires if you find yourself in need. I believe somebody else makes glow plug wires up as well. Maybe check leroydiesel.com
#3
12-15-2015, 10:22 PM
Common problem for these engines to not run the plugs long enough. Unplug the coolant temp sensor on the coolant crossover to set the engine to -40* temps and it will run the plugs longer. If it starts right, sorry but there isnt a official fix that i know of. The gp's are easy to test with a power probe or a wire attached to B+. If you put power to a glow plug with its conenctor unplugged there should be a small spark when the wire touches or if using a power probe (preferred!) the system voltage will show as lower than when you arent applying power. 6.5's start reliably without being plugged in only down to around 40*, i know it sucks but thats life. Below 40 they smoke white and chug a bit til they get a couple minutes of run time. i own two, one has control of its glow plugs and the other i have a switch. Glow plugs are the difference between starting and not starting but after that they still run rough/smoke when cold no mater how long they glow.
