CUCV early Glow Plug burn out - What is the cause?

[Commander5993]

Hey all, I've went through 3 sets of AC Delco 60G glow plugs in the last four years. I know the CUCV can be hard on plugs, but this is not normal. But I can't find the issue. I know if one or more plugs burn out, then the rest get over voltage. But I shouldn't even have the first plug to burn out in just a year. I replaced them early last winter due to the same reason. All work fine for a while, until they don't. $90 a set is getting expensive. Anything I should be looking for??

Any Suggestions or Advice Appreciated

 

[WWRD99]

Hey all, I've went through 3 sets of AC Delco 60G glow plugs in the last four years. I know the CUCV can be hard on plugs, but this is not normal. But I can't find the issue. I know if one or more plugs burn out, then the rest get over voltage. But I shouldn't even have the first plug to burn out in just a year. I replaced them early last winter due to the same reason. All work fine for a while, until they don't. $90 a set is getting expensive. Anything I should be looking for??

Any Suggestions or Advice Appreciated

I'd say there's 2 main things that'll do that. If you have the resistor still hooked up, it could be giving more than 12 volts to them. Second is the single wire temp sensor, or double if it's been changed, could be broken or the wire is not giving resistance to the glow plug card, making the glows turn on for the maximum amount of time plus the long 3 after burns. Either one is pretty easy to find with a basic dvom hooked to the output of the glow plug relay. You'll see the volts and how long they're on. You should also see the glow plug after burn on the voltage gauge going low when they turn on. I've used 60gs for years and do replace every 2 years just because I'd prefer to keep the truck starting in cold weather and not replacing them when it's 15 out.
How cold does it get where you are?
Sent from my SM-S906U using Tapatalk

 

[Commander5993]

I'd say there's 2 main things that'll do that. If you have the resistor still hooked up, it could be giving more than 12 volts to them. Second is the single wire temp sensor, or double if it's been changed, could be broken or the wire is not giving resistance to the glow plug card, making the glows turn on for the maximum amount of time plus the long 3 after burns. Either one is pretty easy to find with a basic dvom hooked to the output of the glow plug relay. You'll see the volts and how long they're on. You should also see the glow plug after burn on the voltage gauge going low when they turn on. I've used 60gs for years and do replace every 2 years just because I'd prefer to keep the truck starting in cold weather and not replacing them when it's 15 out.
How cold does it get where you are?
Sent from my SM-S906U using Tapatalk

Hi WWRD99 appreciate the info. Temps here as of late, have been in low teens at night. 20's during day. But it supposedly got above freezing today, although I didn't see any ice melting. But I went to drive the truck a week or so ago, and it had only been like 30's that previous night, and I had a time getting the truck started. Cranked just fine, but didn't want to hit. Had to feather the "gas" pedal and finally got it to stay running, once it warmed up it was fine for the rest of day doing errands and hauling some lumber. Smoked a good bit at first because of not burning all the fuel.

I didn't know the "norm" life was only 2 years
I thought it should have been a lot longer. So idk, maybe I'm not getting to much worse than normal I guess.

I'll have to check about the resistor, as I can't remember. I do know I've tested the voltage before, but can't remember the details now.

I do also know that the temp sensor isn't working. Back a year or so ago, as soon as I would start the truck, the temp light begins to glow. As the truck warms up the light goes full brightness. But for no apparent reason, the truck is not overheating at all. (I had a thread about this on here somewhere back then) I replaced the temp sensor once, same issue. After some months I replaced the sensor again last year with an AC Delco brand I believe, but it still did the same thing. But I never could figure out why. I got tired of seeing the light, and since it was just always on that doesn't tell me anything. So I unplugged the sensor with the intent to upgrade my actual temp gauge in the truck. The one I currently have shows cooler temp than it actually is, but it still gives me a general idea.

With that said, I did not know that the temp sensor also controlled the glow plug card. Should have thought about that though
I do have a GP manual override safety switch that I could use (after replacing plugs) but would have to unplug the card though. I installed the manual switch not long after I got the truck back about 13 years ago, as a "just in case" measure. As I had read at the time about guys having issues with the cards. But I've never used it other than testing. I've always just let the card do its thing.

I'll have to pull these plugs when I can get the truck into my barn. not going to try to start it now, as it has been in low teens at night this week. Supposed to be getting 5 to 7" of snow tonight now. Hope I don't need to go anywhere for a few days. I live out in rural farm area, and it takes the little towns around here a good while to ever get the roads decent, as they only have a few plow trucks and don't hardly use any salt.

I'll test each plug and keep the "good ones" for spares. I ordered another set of AC Delco's from our local auto parts store, supposed to be in tomorrow.

Thanks for the info WWRD99 this gives me a place to start to troubleshooting and go from here

 

[WWRD99]

Hi WWRD99 appreciate the info. Temps here as of late, have been in low teens at night. 20's during day. But it supposedly got above freezing today, although I didn't see any ice melting. But I went to drive the truck a week or so ago, and it had only been like 30's that previous night, and I had a time getting the truck started. Cranked just fine, but didn't want to hit. Had to feather the "gas" pedal and finally got it to stay running, once it warmed up it was fine for the rest of day doing errands and hauling some lumber. Smoked a good bit at first because of not burning all the fuel.

I didn't know the "norm" life was only 2 years
I thought it should have been a lot longer. So idk, maybe I'm not getting to much worse than normal I guess.

I'll have to check about the resistor, as I can't remember. I do know I've tested the voltage before, but can't remember the details now.

I do also know that the temp sensor isn't working. Back a year or so ago, as soon as I would start the truck, the temp light begins to glow. As the truck warms up the light goes full brightness. But for no apparent reason, the truck is not overheating at all. (I had a thread about this on here somewhere back then) I replaced the temp sensor once, same issue. After some months I replaced the sensor again last year with an AC Delco brand I believe, but it still did the same thing. But I never could figure out why. I got tired of seeing the light, and since it was just always on that doesn't tell me anything. So I unplugged the sensor with the intent to upgrade my actual temp gauge in the truck. The one I currently have shows cooler temp than it actually is, but it still gives me a general idea.

With that said, I did not know that the temp sensor also controlled the glow plug card. Should have thought about that though
I do have a GP manual override safety switch that I could use (after replacing plugs) but would have to unplug the card though. I installed the manual switch not long after I got the truck back about 13 years ago, as a "just in case" measure. As I had read at the time about guys having issues with the cards. But I've never used it other than testing. I've always just let the card do its thing.

I'll have to pull these plugs when I can get the truck into my barn. not going to try to start it now, as it has been in low teens at night this week. Supposed to be getting 5 to 7" of snow tonight now. Hope I don't need to go anywhere for a few days. I live out in rural farm area, and it takes the little towns around here a good while to ever get the roads decent, as they only have a few plow trucks and don't hardly use any salt.

I'll test each plug and keep the "good ones" for spares. I ordered another set of AC Delco's from our local auto parts store, supposed to be in tomorrow.

Thanks for the info WWRD99 this gives me a place to start to troubleshooting and go from here

Just to clarify the temp sensor that turns on the wait light is different than the one that turns on the low coolant light. The one to look for is on the rear of the drivers side head....way back by the vacuum pump. The manual switch if you did a ground to the 3rd wire on the glow plug card harness you can use that with the card installed. I assume you have a gauge for the temp that isn't stock? Yes glow plugs should last a good bit. I wouldn't want to change them that much since I have 4 of them. Glow plugs have almost doubled in price the last couple years. I didn't know it got that cold in Mo!! That's as cold as Pa is right now except we don't get snow anymore.

 

[Barrman]

Preventive maintenance wise changing the glow plugs when you live some where with expected 0° nights is a pretty wise choice every 2 years. As pointed out Doug it sure beats doing it on a cold dark rainy night.

The rest of us though can normally get 5-10 years or more out of a set of 60G glow plugs. But, the first time you get a puff of start up smoke with a stumbling engine that clears in a few seconds. Start thinking glow plug change.