glow plugs 6.9

[JAKRANCH]

found out the hard way that 6v motor craft plugs don't like glowing more than 5 second on manual switch. I had heard 15 second was the limit and also that various plugs can run forever with 12v so I didn't worry about it. My mistake...... My question is, ac delcos have the spade connector will they run just as good as the motorcrafts? I've heard they take 12v all day long and are just fine.

Edit have researched quite extensively. Finding lots of contradictory information. Would like personal experiences on long lasting 6 9 glow plugs with manual control. Trying to set my buyer up right with my truck I'm selling. If the 6v motorcraft plugs are the best ill just tell him to be careful and not toast them like i did.

 

[WarNose]

Better do a search about using anything other than Motocraft/Beru glowplugs. You dont want to use thise ac delcos.

 

[JAKRANCH]

I have searched I've found conflicting information everywhere I look

 

[Oledirtypearl86]

I have searched I've found conflicting information everywhere I look

If unsure try them out and pull them often to check for possible problems

 

[JAKRANCH]

This is the first time I've had an issue, I bought my other truck with manual control glow plugs(also 85 6.9(they are spade connectors)) and I've run them for 15 seconds plus with no issues. The ones I'm asking about are motorcraft plugs that are newly installed with less than 20 starts on them.

 

[riphip]

Are you still hooked to the controller? I think you have to disconnect/cut the purple wire from the old style controller or it will keep cycling the glowplugs.
Has been a long time since I changed all of my trucks to the updated controller. Was very well worth the change.

 

[JAKRANCH]

Yes controller is disconnected

 

[Nidenn]

Not sure what controller or manual switch is. But I put in Motorcraft plugs in 2015 and they seen to be working fine still. My '87 6.9 was my daily driver for about a year and has been my toy since then for forest service roads. Don't drive it much in the winter but just for the hell of it I tried to start it during the cold spell last month. Block heater wasn't plugged in! I hit the glow plugs for about 10 seconds, counted to 10, then hit the glow plugs again and it turned over and started fine.

 

[Noiseydiesel]

I did an '87 6.9 and went to the Motorcraft glow plugs. The Autolites are known to expand and get stuck in the head. I wired in a new controller with a toggle switch to the power supply wire. This way I can get into the truck and turn on the controller for the 8/10 seconds I need to warm the plugs for the day until it starts.
After that turn off the power supply to the controller and not worry about turning on the key to roll up/down windows and running the glow plugs without reason. Also the toggle switch allows you to turn off the system upon start up and extend the service life. If it's running, why do you need to plugs energized?
If someone who has no clue about it climbs in, you can still flip the switch and the system will run as designed.

 

[Booyah45828]

Figured I'd add to this.

Years ago when I bought the bus(1984 6.9 idi), it wouldn't start without ether. The wts light would come on for a few seconds and go out. I knew it had glow plug issues so I oredered a set on the way home before any diagnosis. The plug I ordered were the AcDelco # 12g because I read at the time they were self limiting and knew that if it was the module, I'd just switch it over to a push button, install the new plugs, and run it. Well, turns out the module was trashed but the plugs were good so I did the manual button mod without changing to the 12g's. This went well for several years.

A few weeks ago I went to start the bus because I had to move it. It was 15*F outside and I held the button for 15 seconds which was most likely too long. Tried to run, but would't. Used a little ether while cranking and away she went. Anyways, I checked the plugs and had 6 of 8 dead. No biggie because I had the 8 new 12g's sitting in a box.

Last night I went to do a test run on them before install. What a mistake

Using a 12v jump box, I hooked all the plugs up one at a time, negative lead on the threads, positive lead on the spade, 10 seconds on and then 2 minutes to cool off.

First two went okay, the tips that were orignially square cut, ballooned out and became rounded, but didn't swell diameter wise. I heard some sort of puff like pressure release, but no big deal I thought.
3rd one exploded the end of the tip completely off, hitting me in the lip . Fortunately I had safety glasses on, which is pretty rare for me. After that, I modified the test to start holding them inside a piece of schedule 80 black pipe instead of out in the open.

4th one lit with no surprises like the first 2.

5th one exploded as well, but this time the tip stayed on.

6,7, and 8 all acted like the first 2.

Now, here's the kicker. After testing the remaining 6 a 2nd time - 4 lit, 2 didn't. 3rd test with remaining 4 - Only 2 lit. Tested the 2 workers 2 more times for a total of 5 lights, and the remaining 2 stayed good.

So, use this info for what it's worth. But the 12g's are definitiely not an option in my opinion. Yeah, no swelling, but having them explode/give up the ghost that quickly is just as bad.

I googled "12g exploding" and found some forum hits and a youtube video sharing similar experiences. So my experience isn't unique. I think the next step is to try the acdelco 60g's because I see none of my parts suppliers list the 12g in stock anymore. I think the 60g is self limiting as well, so hopefully they go as planned. If not, I'm not sure what I'll use with my push button. Not really a fan of the 6v plugs because of the lack of self-limiting, but I'll use what I have to.

 

[Booyah45828]

Here are some pictures.

The first is the 2 remaining ones that work. They both read around 18 ohms on an ohmeter fwiw.

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The next is the 4 that don't. No real change visually from the 2 that do work. These read open on the ohmeter.

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This final pic is the 2 that exploded. You can see the one on the left is missing the end completely.

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[FordGuy100]

Are you talking about the 12V plugs from iirc 5.7/6.2 GM applications?

 

[Booyah45828]

Not sure what they were all used in. The few interchange sources show they were for the 4.3 and 5.7 diesels. I got my info to buy them from this thread here https://www.oilburners.net/threads/12v-glow-plugs.34449/

 

[Booyah45828]

Well, tried the acdelco 60g plugs last night. All 8 tested well with no swelling or exploders. They took about 10 seconds to fully heat up. They are also self limiting and I tested that by leaving one hooked up for a minute. Let it cool and it looked like the others. I tested one of the good beru plugs I removed, and it heated up in 5 seconds fwiw.

I think the 60g will work well with my manual pushbutton setup. They take longer to light then the beru, but I don't have to worry about holding onto them for too long and burning out. I'll report back if any issues arise. It takes half a crank to start now so I'm impressed.

The only issue with the 60g is the threaded body is shorter then what is required. I own a lathe so I simply machined some of the hex off to make it work. If you don't do this, it will interfere with the threads in the head. I'm not worried about doing this, the smaller amount of hex left should create no issues.

Here is a picture of the plugs. From the top down is : Removed BERU idi plug , AcDelco 12g, Machined AcDelco 60g, Unmachined 60G.

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The hardest thing I ran into was the water outlet covers the #1 plug pretty well. Not sure if this is a problem in the trucks.
Here is a pic from the side.

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Here is one from the top.

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You can't get a socket on this one, so I bent up a few 3/8" box end wrenches and moved it a little at a time. To get the old one out I had to break off the connector on top. The new plug being shorter, it slid in with no issues.

So, the 60g isn't a direct swap. It requires machining on the body to work correctly. Once done though, they seem to work as intended for a manual button system.