Glow Plug diagnosis

[SnowDrift]

Upon a cold start, will glow plugs be hot at the terminal, after the wait to start period?

Trying to help get a friend's 6.5 going ('96-98 model chassis/cab model). Lift pump seems strong - blew fuel up to the hood, when I tried to bleed it.

I felt the glow plug bodies on the driver side and none felt warm, to touch.

Truck was from Florida and hasn't been started since February. I guess when he bought it, they had to give it a shot of ether to get it to fire up.

 

[Will L.]

Mine doesn't.

Forget the ohms test. I uave had them read good and not work, and read bad and work. And yes, I inow how to read ohms proper, I am a Journeyman electrician. Pull and bench test them. Reinstalling with antisieze.

Do a compression test while they are all out.

Cover both issues at once.

Also test for fuel pressure/ volume. Sometimes a dead lift pump will let fuel drain back and ether gets it to start and then IP can suck through toasted LP. Clear line the 1/4" return out the front if the IP & check for bubbles.

 

[SnowDrift]

And yes, I inow how to read ohms proper, I am a Journeyman electrician. Pull and bench test them.

Will, this made me grin. I have no question of your authority on things like this, my friend, knowing your background. If you told me the best thing to do is to take the glow plugs out, soak them in a Frosty from Wendy's before reinstalling, I may think it strange, but I'd do it anyhow.

Thanks!

 

[Husker6.5]

The Frosty fools the glowplugs into thinking it's Winter and they then come on. Makes sense.

 

[Husker6.5]

Hadn't been started since February. CLICK! IF a battery charger was used to "boost" starting and the glowplugs were cycled while the charger was on, then there's the problem - the glowplugs were fried from too high of voltage (charger) being applied.

 

[WarWagon]

Well IF the either use didn't kill the plugs outright...

If you don't want to remove the glow plugs I use an IR temp gun on a cold engine. Measure the engine temp around the plug area. Light the plugs off several key cycles and then see if the temperature changed at all. It may take a min to raise the temperature after cycling the plugs. Measure that all the plugs get 12v.

 

[consaka]

Hadn't been started since February. CLICK! IF a battery charger was used to "boost" starting and the glowplugs were cycled while the charger was on, then there's the problem - the glowplugs were fried from too high of voltage (charger) being applied.

I have a hard time imagining this happening with 60G plugs. Some of those old one maybe but I have battery charger on my test engine right now and it runs solid when I am messing around with starting and restarting the engine. Amperage comes through the batteries and shouldn't be detrimental to the GP's.

 

[Will L.]

@SnowDrift Mmm, frosty...

Starting fluid will take out any glowplug.

@consaka
The battery charger - I have not ever tried on bosch duraterm or AC 60G. Makes sense the self limiting would just shut 'em down quicker. Amperage is what it is, but as resistance or voltage goes up, the shutdown time would just come sooner. Good thinking. Now when I put in new ones, I have something to test on the old ones coming out. All 8 of mine are still good, but no way am I putting old gp's back in when the engine is coming out for a refresher just because...

 

[Husker6.5]

Battery chargers, especially the big commercial units that have 200-300 amp "Start" settings on them, put out 15.0-15.5 VDC. A fully charged battery at rest is 12.6-12.8 VDC. When you cycle the glows, battery voltage will drop to as low as 11.2 VDC. They are designed to operate at between 11.0 and 12.5 VDC. When on a commercial charger on "Boost" or "Start" setting, you are still feeding 15.0 VDC or higher to the glowplugs.

On a couple of other threads I related the story of the Lot Monkey (who, despite my calling the dealership the afternoon before and telling them that I wanted to do the cold-start when I got to their dealership in Mooresville, NC first thing the next morning) was, when I arrived, in the middle of cranking over my '98 Burb while on their big wheeled charger. The idiot evidently didn't know what the Wait To Start light meant and had ran the batteries down trying to start without glows on a 20° December morning, then evidently got the bright idea to haul out the dealership's monster charger, hooked it up, saw and realized the Wait To Start light, and fried out all 8 glowplugs off of the charger voltage. When I arrived there he was, still vainly trying to start it cold with dead glowplugs. We eventually put it on the block heater and then started it a couple of hours later. Three days later when I got back home to Lincoln, I pulled the glowplugs. All 8 of them, 60G's, were toast. I replaced them with Bosch Duraterms.

 

[consaka]

Battery chargers, especially the big commercial units that have 200-300 amp "Start" settings on them, put out 15.0-15.5 VDC. A fully charged battery at rest is 12.6-12.8 VDC. When you cycle the glows, battery voltage will drop to as low as 11.2 VDC. They are designed to operate at between 11.0 and 12.5 VDC. When on a commercial charger on "Boost" or "Start" setting, you are still feeding 15.0 VDC or higher to the glowplugs.

On a couple of other threads I related the story of the Lot Monkey (who, despite my calling the dealership the afternoon before and telling them that I wanted to do the cold-start when I got to their dealership in Mooresville, NC first thing the next morning) was, when I arrived, in the middle of cranking over my '98 Burb while on their big wheeled charger. The idiot evidently didn't know what the Wait To Start light meant and had ran the batteries down trying to start without glows on a 20° December morning, then evidently got the bright idea to haul out the dealership's monster charger, hooked it up, saw and realized the Wait To Start light, and fried out all 8 glowplugs off of the charger voltage. When I arrived there he was, still vainly trying to start it cold with dead glowplugs. We eventually put it on the block heater and then started it a couple of hours later. Three days later when I got back home to Lincoln, I pulled the glowplugs. All 8 of them, 60G's, were toast. I replaced them with Bosch Duraterms.

Stock engine will cycle the glow plugs for a bit after the engine starts. Had an alternator on the van at one time that put out 15.5 to 16 volts. I'd think that would have taken out those old glowplugs but maybe most of the amperage was going into the bats. Eventually I got tired of replacing fried batteries and just replaced the alternator.
Are Duraterms supposed to be better than 60G's?

 

[Husker6.5]

Stock ECM will cycle the glowplugs 1-2 seconds at a time 1-3 times after start, not long enough to fry them like the 5-~15 seconds continuously that WTS on a cold start will. 15+Volts from your alternator while running? Surprised you weren't burning out headlights, panel lights, tail/brake/marker lights on a regular basis, not to mention what it did to gauge accuracy!

 

[ak diesel driver]

Duraterms are supposed to heat up quicker is the only difference.

 

[Will L.]

I did bench test comparison on 80034 vs 60g. Bosch heated slightly quicker and running them non stop power so the self regulation is only thing shutting down, they lasted longer also.

Confused on how the self regulated 60g smoked on the boosted voltage, with voltage up, the amp draw is still the same, so wattage (heat output) would just fall. They would get hot quicker, but I thought would still be ok but just shutting themselves off 1-2 seconds sooner. But I am theorizing, and you lived it- so real world beats theoretical lab again.

Possibility of lot mokey giving a spray of juice to help start? I have seen some glow plugs crystalize instantly.

 

[Husker6.5]

I did bench test comparison on 80034 vs 60g. Bosch heated slightly quicker and running them non stop power so the self regulation is only thing shutting down, they lasted longer also.

Confused on how the self regulated 60g smoked on the boosted voltage, with voltage up, the amp draw is still the same, so wattage (heat output) would just fall. They would get hot quicker, but I thought would still be ok but just shutting themselves off 1-2 seconds sooner. But I am theorizing, and you lived it- so real world beats theoretical lab again.

Possibility of lot mokey giving a spray of juice to help start? I have seen some glow plugs crystalize instantly.

No, no external signs of damage from the ether bunny. The bodies of the glowplugs were corroded where the number is stamped, I just assumed in '98 that they came from the factory witb 60G's in them by then. Now my curiosity is peaked. I'll have to grab one of them out of my miscellaneous dead parts collection and see if I can get a number off of the side of it tomorrow.

 

[Husker6.5]

Well, a little WD40 and some 0000 steel wool and the number is 11G, at least on this one. I'm assuming (I hate that word) that the other 7 are, also. The Burb was originally from Orlando, Florida so I don't think they would have been hardly used and not been replaced, either individually or as a set, prior to my getting the Burb.

 

[consaka]

Stock ECM will cycle the glowplugs 1-2 seconds at a time 1-3 times after start, not long enough to fry them like the 5-~15 seconds continuously that WTS on a cold start will. 15+Volts from your alternator while running? Surprised you weren't burning out headlights, panel lights, tail/brake/marker lights on a regular basis, not to mention what it did to gauge accuracy!

I'll tell you it always made me a bit nervous. It ran that way for a number of years and I did occasionally have to replace head lights and running lights. I have replaced the occasional dash light since I got it in '95. Not more then 3 though. Now I have some fancy 250 amp Alternator that barely puts out 13 volts. Beyond irritating for sure since I want 14.7. I am going to have to research either HD voltage regulators or an adjustable regulator.

 

[consaka]

Well, a little WD40 and some 0000 steel wool and the number is 11G, at least on this one. I'm assuming (I hate that word) that the other 7 are, also. The Burb was originally from Orlando, Florida so I don't think they would have been hardly used and not been replaced, either individually or as a set, prior to my getting the Burb.

Ahh that explains a few things. I never had any luck with glowplugs until I started running the 60G's. I have run 60g over an hour on battery being charged with 2 gauge jumper cables. Thats pretty darn tough in my book.

 

[WarWagon]

Now I have some fancy 250 amp Alternator that barely puts out 13 volts. Beyond irritating for sure since I want 14.7. I am going to have to research either HD voltage regulators or an adjustable regulator.

Best charging voltage would be a temp sensor on the battery. Short of that there is supposed to be a temperature compensation built into the alternator regulator. Batteries change voltage with temperature as does the ideal charging voltage. So when you start the engine charging voltage is higher and then goes down as the "sensor" warms up. IMO the temp sensor mounted in the firecracker hot GM alternator regulator is about worthless. OTH the battery temp sensor system on the Dodge I have likes 14.5 - 15 volts and constantly coats the top of the batteries with krap. Theory is great, but, production auto systems simply suck.

 

[Will L.]

11G would definitely eat it on high voltage.

I'll tell you it always made me a bit nervous. It ran that way for a number of years and I did occasionally have to replace head lights and running lights. I have replaced the occasional dash light since I got it in '95. Not more then 3 though. Now I have some fancy 250 amp Alternator that barely puts out 13 volts. Beyond irritating for sure since I want 14.7. I am going to have to research either HD voltage regulators or an adjustable regulator.

Call Power Master tech support. let them know what you have and what you are trying to do. Their engineering staff is top notch and are always glad to help. They can tell you what to get and how to do it, even if not from them. Just can't say enough good about that outfit- top notch American made stuff.

 

[consaka]

Call Power Master tech support. let them know what you have and what you are trying to do. Their engineering staff is top notch and are always glad to help. They can tell you what to get and how to do it, even if not from them. Just can't say enough good about that outfit- top notch American made stuff.

got them bookmarked. Pretty sure it is an AD244 alternator. sure fits nice compared to all the other alternators that have been in that spot. lol It worked pretty good at first. I will be taking a spare alternator with me just in case. Wish the vans had enough room for two alternators.
On topic, I'd like to try some duraterms. A slightly faster light sounds good. I count to 12 with my 60G's.