Unsure about a glowplug issue

[robrike1]

I've got a 2004 F250 6.0 and have been having random cold crank issues. Normally 25 to 35f when I start it in the morning. The last few days I've had to crank for about 8 to 11 seconds before it fires up versus the normal 2 or 3 seconds. When it does get going it blows white smoke for awhile so I was suspecting a glowplug issue. Connected my bluetooth adapter this morning after another hard to start leaving work a and all 8 glowplugs had thrown a code. I suspected GPCM and pulled the connectors and ohm'd them out. Black connector all were fine but on green all but one were open. After checking for wire breaks and even ohm'ing from green GPCM plug to the connector where the glow plug wiring harness was it all showed open. Doing a test on glow plug wiring harness plug directly showed all within 5 ohms so glowplug harness and glowplugs on driver side is good. The wires from GPCM green connector to connector that its into driver side glowplug harness seems to be open. 2 different voltmeter were used.

Another odd thing I think is the black and green connectors battery pin both show 12 volts when key is on engine off. When I turn key off i still have 12 volts at the connectors battery pin. I'm not sure if that is normal or not. I went into this thinking my GPCM was bad and now it seems one side of wire harness may be bad but I still had 8 plugs throw codes rather than 4. I'm stumped and regrouping. If anyone has any suggestions or seems to have had the wire harness from GPCM to the glowplug wire harness connector fail I'd love to hear how it went. It is so weird that that main harness that has the harness from green connector to bus bar connector has all 4 wires open but no other issues with other sensors that branch off that big harness.

Going to clean oil out of turbo inlet hoses I took off to do my work initially and then maybe button it up and see what happens.

Is the 12 volts constant on the battery pins on the glow plug green and black connector normal with key off???

Thanks for any ideas,

Robert

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[robrike1]

Well, I put everything back together after verifying glowplug and harnesses are good. Get good readings off each plug connector going from wire harness to plugs. The problem is the engine harness part that goes from glow plug module to the driver side gp harness. Ohm from one end of plug to other is dead, open. I cannot see a break anywhere but still get codes for 1, 3 , 5 and 7.

Can I just run new wire from glow plug module black connector to part that plugs to gp harness on driver side? Basically bypass the break from one connector to the other in the harness loom that runs over top of block. It has other wires that branch off to sensors and I have no issues with sensors. It is like those 4 wires somehow were severed but d@mn if I can see where.

Thanks,

Robert

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[robrike1]

Well, a little more exploring online says 1,3,5,7 are on passenger side of engine. That thickens the mystery. Is it correct that 1,3,5,7 are on passenger side of vehicle?

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[bismic]

yes .

 

[robrike1]

Ok, thanks. I guess I need to go visit my wiring again. Here is something weird though that leads me to think maybe the glow plug controller module is taking a dump. A few days ago I had codes on all 8 glow plugs and white smoke and a strong diesel smell in exhaust when truck was warming up. After messing with it all day Saturday taking out intercooler hoses and all now I get 1,3,5, and 7. Codes were P0671 thru 8. No codes to indicate a GPCM fault or failure. But it kind of seems like one.

I've cleared all codes and will try a cold start tomorrow and see what I get. I'm thinking GPCM, what do you all think?

Thanks,

Robert

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[DEEZUZ]

You need to wiggle test the green and black connectors. I've had the wiring back out of the plugs. Make sure all the wires are seated tight....

Ohm out the glow plugs through the glow plug harness... Cold I see 0.9-1.0ohm... If you see a crazy number then that plugs bad... Also check to see the harness is seated into the rocker box... Guys never clean the corrosion out and the harness never seats right..

 

[bismic]

More often than not, if you have all 8 glow plug codes, the issue is the control module.

 

[robrike1]

More often than not, if you have all 8 glow plug codes, the issue is the control module.

Thank you for the replies. Tried to start it this morning in about 28 degree weather and it was a no go. 1,3,5,and 7 kept showing up in codes. Cleared and recycled key and they popped right back up. Plugged it in and drive car to work. Got home tonight and coolant temp was at 103 degrees and it fired up although it ran funky for about 20 seconds. Understandable considering 4 plugs were out.

All the dealers around me would have to order a GPCM and was 2 to 5 days out at $200 plus. Same Motorcraft part was on Amazon for $103 so that will be here Monday. I read the comments on the part and there were no fouls about a knock off part. Worst case the GPCM isn't it and I order some plugs and a couple harnesses. I replaced all glow plugs and the 2 harnesses about 5 years ago and haven't put but 20,000 miles on it so being Motorcraft plugs surely they are still good.

Any harm running it the first couple minutes after starting it with 4 bugs out. It will be plugged in all night before starting.

Thanks,

Robert

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[DEEZUZ]

No that'll be fine.

 

[bismic]

For future reference .... check out prices at Ford Auto Nation White Bear Lake:

https://parts.autonationfordwhitebe...y-yc3z12b533aa?c=aT1NRTA4MjgwNSZyPWxheWVyXzM=

 

[robrike1]

For future reference .... check out prices at Ford Auto Nation White Bear Lake:

https://parts.autonationfordwhitebe...y-yc3z12b533aa?c=aT1NRTA4MjgwNSZyPWxheWVyXzM=

Thanks for the link. I'll check them out for some other parts I need soon. I peeked at there site and prices seem good.

I did check the connections and made sure they were seated properly and still have same 1,3,5,7 not working. Those have been working for 5 years so pretty sure the plug on the gp tip is seated well. I'll know more Monday afternoon.

Thanks for all the tips. I'm gonna plug it in tonight and run it around tomorrow.

Robert

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[robrike1]

Well, GPCM came in yesterday while I was at work. I got home this morning and installed it and cleared all codes with Forscan lite on my phone and it started fine although it was plugged in and coolant temp was about 93 degrees. No white smoke after starting and no codes. I stopped and started it a few times because I read it takes 3 failures of plugs to throw a code??????? Dunno. So far so good. Going to be 37 tonight and I'll try a cold start with no plugging in tonight. Seems to be solid though.

I do have one more thing though. I still get a little surge or hunting at idle but my steep drop and rise of voltage on Edge CTS monitor are gone with new GPCM. No tunes on this truck. I'm wondering if I have a FICM issue. Voltage at KOEOFF stays at 48 volts and during cranking stays there. Running I rarely see it drop below 47.5 min and most times it holds steady at 48 to 48.5 running. The 12 volts in to FICM bounces from 12 to 13 but never below 12. But each idle rise and fall shows a rise and fall of the 12 volts coming in to FICM. Once everything warms up I don't see this issue at all that I recall.

If anyone knows if that is normal during warm up I'd love to hear. I'll post my final results tomorrow when I get to work and get settled in.

Thanks for the replies and comments before. All greatly appreciated.

Robert

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[DEEZUZ]

You might be seeing a voltage spike cause rpm change which changes alternator charging...

Usually hunting/surging with these is ICP/VGT/Turbo related.

Each one of those has several variables that comes into play as well.

 

[robrike1]

You might be seeing a voltage spike cause rpm change which changes alternator charging...

Usually hunting/surging with these is ICP/VGT/Turbo related.

Each one of those has several variables that comes into play as well.

Cold start this morning went off without a hitch. I still had a little white smoke the first few minutes but once coolant hit about 95 or so on Edge monitor it was gone. That was letting it idle and warm up. I usually start it about 5 minutes before I leave and finish getting stuff for work.

Im not seeing sharp drops in voltage like I was in a previous post. Since cleaning a couple grounds and replacing strap from cab to frame things were better as far as alternator kicking in and out during warm up. The GPCM seems to be the icing on the cake. I have a feeling the plugs kicking off and on for up to 5 minutes was a sign it was about to cr@ p out.

Didn't check for codes but will later today. It started within 2 seconds in 36 degrees today so I'm confident all codes will not reappear.

The GPCM was a Motorcraft I got off Amazon. Still in Motorcraft packaging, nothing fake or knock off about it. I was worried about that but it was genuine.

Thanks to all that commented. I need to create another post about an oil leak I found at base of turbo will taking hot side intercooler tubing off. The fun never ends once you start a project. Always find 3 other things that need attention.

Thanks,

Robert

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[bismic]

Just an fyi - the Motorcraft packaging and labels can be faked as well. The ability to provide counterfeit parts that look like the original in every way is quite remarkable.

Not saying yours is or isn't, but buying off of Amazon significantly increases the odds for it being counterfeit.

 

[robrike1]

Just an fyi - the Motorcraft packaging and labels can be faked as well. The ability to provide counterfeit parts that look like the original in every way is quite remarkable.

Not saying yours is or isn't, but buying off of Amazon significantly increases the odds for it being counterfeit.

That's a good point. Amazon has developed a reputation for having questionable suppliers sometimes.

So far so good. Fired up in under a second this morning at 33 degrees. I need to capture some good data graphs on FICM info and other settings to try to figure out my hunting idle during my first few minutes of warm up. Just varies up and down randomly by a couple hundred rpm even after 2 minute glow plug cycling expires. By then I assume alternator is on full time and not cutting in and out.

Robert

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[bismic]

There is a PCM software version that intentionally "cycles" the inlet guide vanes to the turbo for a bit after start up. It is to prevent these vanes from getting stuck. Maybe that is all that it is with the "hunting idle"!

Glad the GPCM has resolved your cold starting issues.

 

[robrike1]

Is there anyway I can find out if I have this version with forscan? Or do you need IDS to get a version number?

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[bismic]

Sorry, I don't recall which ones do and which ones don't. It was in a TSB, but I don;t recall the number.

 

[6_Riders]

Is there anyway I can find out if I have this version with forscan? Or do you need IDS to get a version number?

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My 06 cycles the turbo at idle, easy to hear, but it doesn't "stumble" just changes the exhaust note.... Note; I do have a 4" straight pipe exhaust.

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