searched this and 10 pages into the results i didn't find a brand mentioned so i'm throwing it out there. is there a preferred brand of glowplug? battled cold starting issues all last winter (https://www.ford-trucks.com/forums/1...out-codes.html) and now that i've procrastinated all summer i wanna get it taken care of before it gets cold out.




(FYI on some of the codes, i have an EGR delete and the bottom three codes are a result of me not properly running one of the diagnostic tests )

 

Might want to check power to and from GPCM. All eight bad looks suspicious. There is a fusible link in the harness near the passenger side battery. I just snag gp's from the dealer not too expensive, but then again, I haven't done 8 at a time before. You can check gp's with a meter using this:

It looks like the GPCM is really 2 units in one box.
Glow plug to ground 0.1~2 Ohms
Glow plug connector to GPCM connector Less that 5 Ohms

Pin #3 on both is the VBattery

Green connector
pin #1 is gp#5
pin #2 is gp#7
pin #6 is gp#1
pin #7 is gp#3
pin 8 goes to the PCM
pin 9 goes to the PCM

Black connector
pin #1 is gp#6
pin #2 is gp#8
pin #6 is gp#2
pin #7 is gp#4
pin 9 goes to the VPwr

 

well, it's "only" six of them haha. going to ohm the harnesses tonight just to see though, thanks.

 

Ah, I missed 3&6 was still working. It could fire up on those two and the rest will be along shortly.

 

that's what i suspect actually. could be an interesting fall if i don't get them fixed stat, as i think i'm dealing with a bleeding-down HPOP now too, ha.

 

results:

gp1 - 217 ohm
gp2 - 2 ohm
gp3 - 2 ohm
gp4 - 495 ohm
gp5 - open loop
gp6 - 2 ohm
gp7 - open loop
gp8 - 7 ohm

could 5 and 7 have fully failed or is it more likely the harness has failed?

my original glow plug brand question still stands as well, haha.

 

IMO, more than likely on the harness side... I can see 1 maybe 2 going bad... but I found that on the 6.0 it's quite rare

 

I've changed 5or6 now (two no my own truck) and only 1 was "open". It looks like the two that ares not failing are on the verge of crappin out. It looks like the 5ohm figure I posted above is for the harness so you could wring those out also. It very easy to break the connector at the GP, you may end up needing the harness(s) anyway.
As I posted above, I get mine from the dealership parts counter ($12-14iirc) but someone here may have a better idea. I think I would buy 8 in your situation.

Note that the 0.1 to 2.0 ohm for the GP's are JUST the plug not the plug and harness.

 

Got mine from the dealership along with the harness. It was only like 50 something bucks for the harness and a plug.

 

It depends on your build date. After 9/22/03 and you need the

2004 Motorcraft Glowplugs $9.25 at Dieselfilters.com

While you are there, grab you some filters!
Motorcraft Oil Filter is $17.36
Racor Fuel Filter $35

Check the prices, see what you need! $43 for GP harness there too.

 

I have had acceptable service life from the Motorcraft glow plugs. Replace the harness also (like everyone else is saying) - unless it is fairly new already.

As 99Expy is steering you ........ be sure to get the proper glow plug

In 2004, the piston was modified (updated bowl design). Due to the design change of the piston, the glow plug has been made shorter by 1.2 mm. If the longer glow plugs are installed into an engine with updated pistons, glow plug to piston contact will result, ending in potential engine failure.

 

thanks guys. i did see the change in '04 plugs info in my search, but looks like Motorcraft parts win again (no surprise i suppose). last year when i was looking into all this i saw a demonstration video for some other glow plug that powered three brands at once next to each other and one heated far and above faster and hotter, couldn't remember which it was.. i know it was aftermarket. just a thought.

 

found it:


reading through the comments it looks like everyone debunked what turned out to be a sales pitch haha. motorcraft it is.

 

Definitely get a new harness when you do it. More than likely your old one will be pretty brittle. Also, it makes it so you don't have to be careful removing it. lol