Glow plug troubles

hopp · **Joined:** Wed Sep 20, 2017 3:11 pm **Posts:** 38

Hey guys,

I went to change my glow plugs as they were not functioning and reading infinite resistance. When I went chnge the plugs I found 1 and 2 had the harness disconnected at the glow plug. After I removed the battery and alt bracket I decided to remove #1. I put a 1/4 10mm deep well and extension on and then attached a ratcheting screwdriver to the extension to keep from applying too much force. to my surprise it turned CCW easily with two fingers -- and kept turning. It turns CW with two finger and keeps turning. I don't want to try and pry it out unless I hear that there's some sort of o-ring holding it in the hole. Anyone think it's stripped? If so, how come it's not a big noisy leak? If it is stripped, short of pulling the head, what are my options?

Just to compare I tried #2. It won't budge with an estimated 5ft lb on the old finger spec torque wrench. I plan to hit that with pb blaster and try agin later.

Any ideas? I really need at least a few working glow plugs as I'm in Northern Ontario and the temps are now down around 0F.

Thanks.

GordnadoCRD · **Posted:** Fri Dec 15, 2017 3:40 am

Too possibilities I can think of: It may be, that your deep socket is a little too short on the deep diameter section, and it is preventing the socket going far enough down to engage the GP hex drive portion. If you find that to be the case, IDParts has this cool little tool to fix that.

The other possibility is that the tube section between the hex portion and the seal end about 3" further down, has snapped, and the hex is no longer connected to the threaded portion. If that is the case, (the electrical stud portion that the boot goes around is floppy,) then you probably need to pull that, and as much of the internal electrics you can get to, out of the way, and use an easy-out tapped into the tube, to unthread it (after soaking with PB Blaster).

hopp · **Joined:** Wed Sep 20, 2017 3:11 pm **Posts:** 38

The deep socket is really thin being 1/4" drive and seats well over the hex portion.

I bet one of the previous owners twisted apart #1 and just left it in the hole. I guess I'll have to carefully remove another GP to make sure it isn't ceramic before I go yanking a GP apart while it's still installed. If I find out it's ceramic I will put #1 replacement on hold until spring. What are the odds of ceramic GP with 172k?

So far I can't get #2 to budge but I'll take my time.

GordnadoCRD · **Posted:** Sat Dec 16, 2017 3:23 am

hopp wrote:

The deep socket is really thin being 1/4" drive and seats well over the hex portion.

Well that one is ruled out then.

I bet one of the previous owners twisted apart #1 and just left it in the hole. That's as good a guess as any.

This, I suppose is where I'll offer my very limited experience, as I am by no means an expert on broken glow plugs. I have, however come across a dozen or so. I will be referring to the photos below.
The examples of this type that I've ever dealt with, were always separated between the hex, and the threads. Beyond that, they were without exception separated directly below the hex secton, and above the round body section located between the hex and the threads. (I hope that makes more sense than my previous description.) Between the tip, and the round body section is the tapered seal. Similar to 1960s Ford spark plugs, this seals between the combustion side, and the atmospheric section of the plug. The round body section between the threads and the seal is the only part with compressive pressure, and this compression is how torquing the plugs accomplishes the seal.

The middle image is of failed ceramic plug tips, and the final image is the general idea of the assembled internals.

If, indeed, the tip is ceramic and is going to fail, it most likely has already happened.
By moving the wire attachment terminal around to find out if that moves the hex section, it will have no ability to cause tip breakage.
If the hex portion flexes around, then failure is as expected, and pulling the terminal and hex away will not cause it to detach either.
Nor will extracting the portion of the heat element above the tip.

I guess I'll have to carefully remove another GP to make sure it isn't ceramic before I go yanking a GP apart while it's still installed. If I find out it's ceramic I will put #1 replacement on hold until spring. What are the odds of ceramic GP with 172k? I think better than even, but not to the realm of impossible.

So far I can't get #2 to budge but I'll take my time. Soak, Soak Soak!

Reference photo of the R428 glow plug.

These are not a fast-heat type, but should serve for explanation purposes.

hopp · **Joined:** Wed Sep 20, 2017 3:11 pm **Posts:** 38

Thanks for all the help so far GordnadoCRD!

So I've gotten #2 unscrewed about 50 revolutions but it doesn't seem to want to come out. Do I just yank it out hard?

Does the red O-ring mean anything?
Edit: Looks like the red ring means 5V Glow Plug! Yay No Ceramics!

hopp · **Joined:** Wed Sep 20, 2017 3:11 pm **Posts:** 38

Partial Success! :BANANA:

#2 down 3 more to go. It is 5V and 6.5k resistance. Now I just have to change at least two more and figure out how to fish all of the tools I've dropped into the engine bay recesses out. :oops:

GordnadoCRD · **Posted:** Sun Dec 17, 2017 1:55 am

I think pulling the electrical wire end boss is the best way to get to the body tube to unthread the remaining part.
and,
Telescoping Magnetic Rods FTW!

https://www.harborfreight.com/flexible-magnetic-pickup-tool-94614.html
https://www.harborfreight.com/15-lb-capacity-telescoping-magnetic-pickup-tool-95933.html

flash7210 · **Posted:** Sun Dec 17, 2017 9:24 am

Glow plug resistance should be less than 3 ohms.

hopp · **Joined:** Wed Sep 20, 2017 3:11 pm **Posts:** 38

OK,

I've pulled #1 apart and have an easy out in the shell of the GP. I need to wait for the tool store to open though because I have absolutely nothing to turn the easy out with. When I recently moved I brought only a portable socket set and three screwdrivers with me.

Interesting thing about the part of the GP I pulled, the hex part rotates free of the electrode as it's only apparently swedged together with the red o-ring. Here's a pic of the guts of a 5v Bosch GP if anyone is interested:

GordnadoCRD · **Posted:** Mon Dec 18, 2017 12:42 am

That is quite possibly very good news!

If you have a small hobby torch, the heat and quench method to loosening metal threads would work quite well if you can get the flame to the center of the tube. It means you don't have to heat the threaded portion so much, as the tube can be compressed with the heat instead and take the stress off the threads that way, and not risk damaging the aluminum head threads.

hopp · **Joined:** Wed Sep 20, 2017 3:11 pm **Posts:** 38

Gordnado,

I think you're right about the heat cycles. I've been hitting it with PB and leaving the block heater plugged in but I can't get the shell of #1 to budge. In fact I put an EZ out in and used a fancy ratcheting handle. The jaw of the handle cracked! Glad it wasn't the easy out getting stuck in there. I'll pick up a propane torch and cycle patiently until it backs out without force. It has to loosen eventually. I was thinking I might possibly get away with a tiny butane torch also.

I was able to pull 4 without issue (900ohms) so I have 2 and a half out. I'm holding off on #3 until my 1&2 weeks kit arrives.

Do I need any honing to remove carbon before I drop in new GP? Aside from anti seize, should I lubricate them with anything?

Edit: Reading comprehension. I'll try a small butane torch first.

GordnadoCRD · **Posted:** Tue Dec 19, 2017 2:16 pm

I wouldn't recommend honing. If anything, AFTER TUBE REMOVAL use small bore non-metallic brushes dipped in or sprayed with carburetor cleaner, but from your picture of the removed element, I doubt it would be necessary.

One more thing, BEFORE FLAME IS APPLIED if there is any minuscule possible chance that PB Blaster or any other combustable has gotten into the middle of the glow plug tube, use CO2 to fill the cylinder before you apply any flame. In fact you should anyway. A "sneeze" could be much more excitement than I would want, anyway. A co2 powered bicycle tire or ball inflator is cheap insurance. CO2 works better than helium as it's heaver than ambient air, and will fill from the bottom of the cylinder.

hopp · **Joined:** Wed Sep 20, 2017 3:11 pm **Posts:** 38

So how would I achieve filling the cylinder? Do you mean shoot CO it in the glow plug? I don't have a battery, accessory belt or alternator on at this time so there isn't going to be any voltage to open an injector. Two glow plugs are out so there's no compression in two of the 4 cylinders.

Isn't that sufficient?

GordnadoCRD · **Posted:** Tue Dec 19, 2017 11:15 pm

I am only referring to the cylinder where the tube is stuck, and the heating element has been removed. I recommend getting a way of spraying co2 gas through the Glow plug tube, this will settle to the bottom and fill from there, just like you were filling it with water. This will displace the oxygen-containing air, and prevent that cylinder from becoming a gigantic spud gun due to the air-combustible mixture when your flame comes through the glow plug tube.
It's a relatively cheap insurance.

Years ago I was helping a friend remove twisted off studs from changing the water pump on his Gen2 Trans Am. The two studs that were above the coolant level heated and came out as expected. Fortunately we were outside, and I learned a few things that day.
Lesson 1) The studs below the coolant level take an enormous amount of heat to get the job done. I also learned that steam and vaporized ethylene glycol produced when said heat is applied into the enclosed air space of a partially drained block can be spectacularly explosive. Fortunately my eyes were closed mid-blink when the detonation happened.
Lesson 2) It takes a bit over a month for Facial hair, Eyelashes and Eyebrows to grow back after being singed off at skin level.
Lesson 3) When your upper and lower eyelashes are fused together it's very painful to separate them. It also creates a bit of a panicked feeling and a mental image that one's face has been melted together along with contact lenses, and all you can smell is burnt hair.
Lesson 4) The detonation can partially empty every house in a full block radius, and cause many people to call 911.

Yeah, CO2 used to clear the cylinder is definitely cheap insurance.

hopp · **Joined:** Wed Sep 20, 2017 3:11 pm **Posts:** 38

Welp,

The #1 GP tube is laughing at the tiny amount of heat I can throw at it. I think I'll put it back together and try to find a local diesel mechanic to pull the remains of #1. Two and four were no issue three is as it was and it appears one is still sealed so I'll see how it runs tomorrow.

Side note: Due to various high energy chemical experiments as a teen I know how it feels to peel your eyelids apart. I also know how it feels when the hole in your eardrum is healing.

racertracer · **Posted:** Wed Dec 20, 2017 3:35 am

On stubborn GP's that are difficult to extract, I use PB blaster overnight and a slow and steady hand turning force on a 10mm gearwrench placed flush/tight to the head. Once it starts turning, i use the deep socket.... tough to me by a diesel mechanic on the YOUTUBE : ) ... haven't broke one yet thank God.

Keeping the gear wrench flush/tight up against the head is key, while applying a small amount of turning force.

WWDiesel · **Posted:** Wed Dec 20, 2017 3:34 pm

You may want to consider purchasing a Damaged Broken Glow Plug Remover Set AM-3381 similar to one of these? :idea:

Being it is no. 1 and easy to get at! It may be money well spent and sure beats having to pull the head just to remove one broken GP! :roll:

Designed for removing damaged or difficult glow plugs from the cylinder head.

hopp · **Joined:** Wed Sep 20, 2017 3:11 pm **Posts:** 38

WWDiesel that is exactly what I will do!

I put the Jeep together tonight. #2 and #4 have sub Ohm measurements now. #1 is just the outer casing but it is holding in the cylinder. I gave it a couple of good acceleration runs to make sure it didn't pop out right away. For the time being I will limp on two glow plugs. It's mostly garaged anyway so I only need to worry if I'm out somewhere for a couple hours. Once the weeks kit gets here I'll change #3. I might even put off fixing #1 until the spring.

Thanks for the help everyone!

Glow plug troubles

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