Author Topic: Glow Plug Replacement LBZ (Read 8294 times)

Sammconn · « **on:** November 15, 2014, 08:25:58 PM »

So a month or so ago, I get a check engine light, and the glow plug light was not going out in a few seconds like it should.
Plug in my code reader to find P0675, Glow Plug Circuit Fault, Cylinder 5.

Now I live way up in northern Manitoba, and with sub zero weather here, it was time to replace it.

Here's approximately the tool list:
22mm lug wrench, tire off gives a lot more room.
3/8 drive, 12mm deep socket
10mm socket
1/4 drive 8mm socket or nut driver
3/8 drive ratchet, and torque wrench
1/4 drive ratchet
body clip removal tool, slotted screwdriver or other suitable removal tool
socket extensions if desired
PB blaster
And some good will from the Big Guy, especially since I'm 750 miles or so from a dealer if things go south.

Sammconn · « **Reply #1 on:** November 15, 2014, 08:29:05 PM »

So the first step is to disconnect both of your batteries.
This way you will not be doing any unwanted welding if the ignition is somehow turned on.
Then jack up passenger side in this case, and remove front tire.
Properly support the front end while the wheel is off, the jack by itself is not properly supported.

Sammconn · « **Reply #2 on:** November 15, 2014, 08:36:21 PM »

Next up remove the wire loom holders from the fender liner, then remove the fender liner plugs and two 10mm bolts on the front side.

Now I just heard y'all cringe at the sight of my frame and all the muck, dirt, rust and whatnot.
Remember I'm at the end of a 200 mile dirt road, and there is no solution known to man to keep this from occurring.
So you end up accepting it, and every now and then you wash it down to see how bad it really is.

Once the liner is removed, its a good time to pull out the PB Blaster and give the electrical connections a good soak.
Also the overspray to the glow plug threads is welcomed as well.

So if you were still unsure of where the glow plugs are, the now darkened spots in this picture are them.

Sammconn · « **Reply #3 on:** November 15, 2014, 08:55:08 PM »

Let the PB Blaster soak for a while, then very carefully check if you can loosen the power lead from the tip of the glow plug.

With one hand holding the wire and connector, and the other gingerly loosening the nut see if it breaks free, or breaks off.
Try to not break them off if you can avoid it, as the new glow plugs do not come with nuts >:(

Flyin6 · « **Reply #4 on:** November 15, 2014, 09:00:34 PM »

You can tell there is no pavement up there!

Sammconn · « **Reply #5 on:** November 15, 2014, 09:02:32 PM »

I chose to replace all four glow plugs while I was in there. 180K on the clock, all original plugs.
It seemed like a good idea to only do this once this year anyway.
I had eight new glow plugs on hand, but am holding out on the drivers side until one fails.

With the power leads all removed, time for the 12mm deep socket and a prayer.

To my surprise they were not frozen into the block.
As you start turning it out, pay special attention to the threads where they enter the head.
You will see very quickly and easily if it is turning with the socket.
My prayers were answered, and all four came out astoundingly easily.
I basically held the head of the ratchet in my hand and twisted my wrist and they turned out.

Sammconn · « **Reply #6 on:** November 15, 2014, 09:05:04 PM »

Quote from: Flyin6 on November 15, 2014, 09:00:34 PM

You can tell there is no pavement up there!

Yeah, all muck and rock. Nasty crushed rock to be exact, black shale in a 3/4" down fashion (read: Arrowheads)

I've just accepted that the layer of natural undercoating 'must help' ::)

Sammconn · « **Reply #7 on:** November 15, 2014, 09:15:33 PM »

I was a little aggressive, or early, on cylinder 1. The electrical lead is very delicate! :o

So now I have to find a new nut...I had some thankfully. They are 4mm studs, and it may be a good idea to have a spare nut or two before you start.
Next up, time to install the new glow plugs.

Open them up, give a quick visual of the tip (straight), and the threads (clear and not galled up).

Then apply a small amount of high temperature anti-seize.

You only need a little on the first few threads, it will flow through the rest as you turn it in.
I was able to turn the new glow plugs all the way in to contact by hand.

Sammconn · « **Reply #8 on:** November 15, 2014, 09:36:02 PM »

So with all four snugged up, I grabbed the head of the ratchet again and tightened the new plugs in.
Torque spec is 13 lb ft, and mine are in the 15 lb ft range as thats as low as my wrench went.

I then applied an electrical connection compound to the stud on each glow plug.

You can make out the copper colour of the compound if you look closely.
Then it's time to clean up the connectors with some scotch bright and replace on the glow plugs.
Remembering how delicate these are tighten them to 18 lb in, or barely tight.

Make sure everything is back where it belongs, no loose wires etc, all your tools out, and replace the fender liner.
It would be a good time to change a fuel filter if its due, before closing it up.

Replace all the plugs and two bolts that secure it, and then re-attach wiring harness points inside.
Reconnect the batteries, then we're almost done.
I cleared the codes, set the clock and called it a job done.

This morning, the glow plugs cycled like normal, and when there was no check engine light or glow plug code, I knew it was a job well done.

Flyin6 · « **Reply #9 on:** November 16, 2014, 08:26:21 AM »

Good write up...Thanks

So all you LBZ guyz...get busy!

KensAuto · « **Reply #10 on:** November 16, 2014, 11:06:22 AM »

Nice job, especially considering the conditions you dwell in!

Sammconn · « **Reply #11 on:** November 16, 2014, 12:35:45 PM »

It is an adventure every time I do anything.
Lots of PB Blaster, compressed air, washing etc, then decide if I'm brave enough to dare it.
I still have my lift pump on the shelf in the garage, as I'm afraid of the fuel lines. :-\

Had overheating issues a couple years ago, and pulled and cleaned the stack.
Then I had the brilliant idea to do the trans cooler also.

Air freight a new one to me, as I cracked the fragile end cap.
I have aftermarket replacement hydraulic lines, so I jumpered the cooler lines together with some AN fittings until the new one came in.
You can drive a bit, and even tow a boat 10 miles, but the whole time I watched the trans temp.
I think just driving you might be OK for a while, I was just happy to get the new cooler before I needed to find out.

cudakidd53 · « **Reply #12 on:** November 17, 2014, 07:05:43 AM »

Nice work- ugly conditions to work with with all that rock dust to contend with! Not sure on the newer system, but early 90's glow plugs, you needed to replace all 8 or the variance in resistance between old plugs and new would lead to an early demise of all of them again...... :(

Sammconn · « **Reply #13 on:** November 17, 2014, 07:54:32 AM »

I'm not sure exactly when the change occurred but I know the LBZ you can, and maybe the LLY.
But you do bring a good point up to make sure it can be done.
I know I could have just done the one that was out however I expect I would have been back in there if I had. Part of me expects to be in the drivers side yet this winter. Would have done it if I had more time but for now it's golden.

JR · « **Reply #14 on:** November 22, 2014, 11:43:59 PM »

Yep, nice job there. I heard it was not that hard, like changing spark plugs really.

Heck I replaced my cooler lines with alligators and not all that happy with them. Seemed like a lot of work for what it did and they still have restrictions smaller than the stock lines inside the fittings. I plan to go to dual coolers on both sides that will double the cooling area and using Summit fittings with larger hose.

Sammconn · « **Reply #15 on:** November 23, 2014, 11:25:03 AM »

The hardest part was taking off the front wheel and fender liner. I want to say about an hour and a bit, and that was locating some tools.

Otherwise quite an easy job.
Now I have heard of guys breaking them off in the head. This would change the 'easy' meter considerably.

Sammconn · « **Reply #16 on:** August 25, 2015, 08:11:59 PM »

So I had two go out on the drivers side.
#4&6, now I've read all over the interwebz that you need to disconnect the steering shaft. I thought what the heck, I'm going to try without.
Short story is that it can be done, very tight 1/4 drive fit, but it fit.
Didn't do all four, they are in my garage, I'm out in the city.

No pics today, just the FYI that #4 can be done without dropping the shaft.

JR · « **Reply #17 on:** November 19, 2015, 12:03:29 AM »

I have been getting this CEL as of late. Cleared it a few times, but no good.

Time for a set. Any brand not to get? I found some KBDP on ebay for $55. Any brand name is 15+ each.

Spacecase544 · « **Reply #18 on:** November 19, 2015, 02:27:39 AM »

Quote from: JR on November 19, 2015, 12:03:29 AM

I have been getting this CEL as of late. Cleared it a few times, but no good.

Time for a set. Any brand not to get? I found some KBDP on ebay for $55. Any brand name is 15+ each.

I always run Bosch. Ran them in a couple of old Mercedes we had (83 & 85...ran like tanks) and always had good luck. I would rather spend the money and do it far less often than buying cheaper and having to redo it.

Sent from my SAMSUNG-SM-G900A using Tapatalk

cudakidd53 · « **Reply #19 on:** November 21, 2015, 09:08:35 AM »

My understanding is that by paying the extra $ you're paying for better quality control. With glow plugs, if one goes bad, the increased amps cause the others to follow in rapid succession. Maybe they have isolated each one now to prevent it, but my previous truck, I only replaced the bad ones and ended up doing all 8 within a couple weeks.

Sammconn · « **Reply #20 on:** November 21, 2015, 05:00:53 PM »

When I first did the passenger bank it was one out.
I chose to do all four as it is more work getting to them than its worth to do four times.

I had one fail in the spring, and another in the summer. I only did the two, as I didn't have my others with me (they take up so much space...poke Sam) the first batch are Bosch, ended up with NGK for the two in the summer.

I believe the newer trucks (not sure which vintage) only supply a fixed current to them now. In days of old though they certainly went in rapid succession once one failed.

I agree on the extra $$ for better quality. Wasn't keen on not being able to source Bosch plugs, so inadvertently I'm a guinea pig. The NGK were better than half price of the Bosch.