# Diesel HELP!!! Update!



## MeanGene (Nov 18, 2008)

I have a 2000 350 Super Duty with the 7.3 Powerstroke. I don't want to hear, you shoulda bought a chevy, or dodge or whatever. I need some serious help please. I think I may have some glow plug issues or the relay that powers them. I forgot to plug in yesterday so it sat for about 24 hours unplugged and could not get it to start today. How hard is it to do these replacements and how can I check to see if one of these things is my problem. Thank You in advance. Gene


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## phantom (Sep 13, 2007)

*Re: Diesel HELP!!!*

I replaced the glow plug relay on my 99 7.3, it was not that hard. If you are just guessing at solutions, it can get expensive.


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## Huge29 (Sep 17, 2007)

*Re: Diesel HELP!!!*

What are the symptoms? Just would not crank or crank, but not go? Not being plugged in would not have affected the plugs in the least, that just keeps the block warm, correct? I believe the heater is just a block heater or radiator heater (on lower radiator hose??) to make starting easier, but nothing mechanical in my understanding.
My neighbor is a ford service writer, give me the details and I can help you, feel free to PM if preferred.


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## BRL1 (Sep 12, 2007)

*Re: Diesel HELP!!!*

Not sure about the Fords, but for GM there is a procedure for testing each glowplug with a 12v testlight. If even one or two glowplugs are bad it will be a hard start when cold, or if the controller is not cycling long enough to heat them up.


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## Greenhead 2 (Sep 13, 2007)

*Re: Diesel HELP!!!*

You need to check the resistance at the module, with a meter. I don't remember the numbers, look them up online or better buy a repair manual. If that checks out then check your plugs resistance. If its your module its a quick fix. If its the plugs then it'll take a few hours to replace them. To have a shop do it will cost you between 800-1200ish, plus parts. Its spendy! Doing it yourself is easy just time consuming, at 1000 for labor do it yourself. The worst part is taking the plugs out. You break off a tip and you get the joy of pulling the head to retrieve it.

The heater does nothing to keep the fuel warm, that's what the glow plugs are for. It keeps the oil warm and makes starting it easier by thinning the oil.


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## nickpan (May 6, 2008)

*Re: Diesel HELP!!!*

There are several things that have to be in order for the 7.3's for them to start good in the cold.

-First check your batteries. These things need at least 10.5 volts under a load in order to power the Glow plugs, the starter and the injectors. If the ECM doesn't see that minimum voltage the injectors won't fire. So make sure your batteries are good. If they are iffy or old have them load test them at like Checker or somewhere. If you need new ones, replace BOTH and at least have 850cca on them.

- A dying starter will also draw too many amps from the batteries, therefore they won't meet the minimum voltage requirement. The starter also needs to be strong in order to spin the motor fast enough to build heat in the cylinders for the fuel to combust. With the cold thick oil, it will put more load on the starter and if its weak, you will have a rough time starting. If your batteries are good and glow plugs are good have the starter load tested at the parts store.

-Glow plugs need to be working. Do you have any white smoke out the tail pipe while the starter is cranking or after it has finally started? White smoke is unburndt fuel and lots will be produced if the glow plugs aren't heating the cylinders. You can check the GP relay on top of the motor and see if you are getting about 11 or more volts on the GP side while the key is on. The relay and glowplugs will heat anywhere from 30 sec to 2 min depending on outside temps. These are notorious for going bad. If that checks out fine then you will have to check the plugs themselves. You can unplug the valve cover harness on either side and ohm the two out most pins on the valve cover part of the plug (4 plugs per side). These are the glow plug pins and should read between .6 and 1.0 ohms i believe in order to be good. Even a few weak or dead plugs will make it rough to start.

If all this checks out fine then you might have injector problems, which is a whole other write up.

When you plug it in you are heating the block, which in turn heats the oil (makes it thinner and easier for the Low pressure oil pump deliver to the High Pressure Oil Pump which runs the injectors), makes easier and faster cranking for the starter because of the less drag of the cold oil, and the cylinders are already heated to a certain point where the glow plugs don't make much of a difference.


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## nickpan (May 6, 2008)

*Re: Diesel HELP!!!*

If you need i can send a good write up on diagnosing the GP system with pictures to an email address. Let me know


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## Greenhead 2 (Sep 13, 2007)

*Re: Diesel HELP!!!*

Yeah what he said haha.


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## nickpan (May 6, 2008)

*Re: Diesel HELP!!!*

This can be very frustrating. I've been dealing with this on mine, 2001 F350, for two years now.Last winter, GPR was toast, replaced. Two dead GP's, replaced all 8. Got warm till this winter, issues were back. Batteries got old, one dead, replaced both. Now having intermittent issues and cold crank so i think its the reman starter that is in there. They are JUNK! Third starter in two years. I have a new High Torque starter being shipped to me now, it is like twice the size as the stocker and remans so hopefully it will solve my issues once and for all. If not, injectors it most likely will be. And they ain't cheap. These trucks should start without bein plugged in until it gets into the single digits if everything is working like it should. Pluggin it in i think is a good way to ease the strain on all the starting components when its cold, cheap insurance.


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## Greenhead 2 (Sep 13, 2007)

*Re: Diesel HELP!!!*

Plugging it indoes help with start up but like you said, its not necessary. I never plug my dodge in, it'll sit for weeks, it fires and runs in less than a second once the fuel heater shuts off. Have you reflashed your motor? My buddy kept having issue after issue with his ford. At high elevations and when it was cold. Long story short a mechanic heard how he had low voltage issues and changed the alternator. The mechanic flashed the motor and it fixed his problem. Apparently the low amps and voltage screwed up the computer.

I unplugged the ECM on my daughters IROC to clear a MAF code. Plugged it back in and the car would not idle. A month later I lost the keys and had to replace the ignition switch. I took off the battery cable, replaced the switch, hooked the battery back up and son of a gun, the **** thing now idles. I played with everything, tcv, maf, tinkered and tinkered. Good thing she is only 15 and not able to drive yet, I'd been killed haha! Oh and after all that she found the keys!! Computers just suck and one stupid sensor can cause you to look at everything except what is causing the problem.


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## nickpan (May 6, 2008)

*Re: Diesel HELP!!!*

I'm just covering the basics first before i go that deep ha. The starter did the "oomph" then "zing" noise the first crank the other day, then a slow crank, then finally fired up. So i'm pretty sure its the starter. If its still hard starting after that i'll have to go to the more complicated stuff.

Your Dodge is a whole different deal than the fords. They don't use glowplugs, but a grid heater and fuel heater. Much better set up. I have yet to see a dodge that won't start in the cold.


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## MeanGene (Nov 18, 2008)

*Re: Diesel HELP!!!*

Thanks to everyone for the replies. I went out this morning and checked the GPR and it tested good. Next step was to check the voltage going out to the glow plugs, but before doing that thought it best to make sure the batteries were charged fully after cranking on it a few times over the last couple days.  Low and behold under the terminal cover of one of the batteries (which by the way were replaced 1-1/2 years ago with the alternator) the + cable end was all corroded. Shame on me, I usually check these thing every year, just got lazy this year I guess. Cleaned all cable ends and battery posts and WALAH.  Cranks and fires like a new truck. Yes I realize plugging in has nothing to do with actual starting of the truck but it sure does make it easier on the starting system to not have cold oil. Not to mention you have hot air blowing out of the heater before you get out of the neighborhood.  Anyway thanks to all who responded. You got me headed in the right direction anyway, and now I'll know for next time, where to start if these other items start to be a problem. I really appreciate it.


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## nickpan (May 6, 2008)

*Re: Diesel HELP!!!*

Glad it was that simple! These trucks are like women when it comes to clean connections of the battery/charging/starting system. They need to be clean as can be


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## blownsmok97 (Nov 8, 2009)

*Re: Diesel HELP!!!*

Gotta love it when it ends up being the simple stuff like that. Frustrating as hell, but once ya figure out, oh it was just that, it sure feels nice knowing ya don't gotta throw money at it. 
Great advice honkerfool, sounds like you know them pretty good. The powerstrokes can be a bugger to start in cold weather sometimes. One thing to try that helps them out with the cold weather start is to switch over to synthetic oil. A lil pricier, but it makes a difference.


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## nickpan (May 6, 2008)

*Re: Diesel HELP!!!*

Yeah they definetly are weak in that aspect. Way to many things to go wrong when there are so many certain conditions that need to be met in order for them to start stone cold. I'm hoping my new starter will fix my issues. Got it today and will install tonight. Its the High Torque Gear reductions monster. These remans aren't lasting long at all. And if that doesn't work i'm afraid my injectors are on their last leg.

Thought about the syn oil but still too pricey for me. And when i've seen other trucks start fine at 0F degrees with 15-40 i just can't justify it! Something else is wrong.


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## MeanGene (Nov 18, 2008)

*Re: Diesel HELP!!!*

I also run the Mobile One Elite 15-40 synthetic blend, and yes its about $80 per oil change but only every 5000 miles not 3000. It has helped. Should I go to a little lighter weight in the winter though. Didn't know they made a lighter weight for the diesel application.


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## nickpan (May 6, 2008)

*Re: Diesel HELP!!!*

i've heard of a lot of guys running 5-40 Rotella T synthetic oil and they really like it. Some run it just in the winter and others run it year round.


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## MeanGene (Nov 18, 2008)

*Re: Diesel HELP!!! UPDATE!!*

My truck is in the shop today :evil: I have had to use starting fluid for the past 5 or 6 days now. I think the glow plugs may be the problem. I'll let you all know when my mechanic gets it done.


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## nickpan (May 6, 2008)

Starting fluid :shock: 

For future reference NEVER use starting fluid in diesels with a glow plug system. A bunch of ether in a cylinder that has a hot glow plug can do horrible damage to a motor, even yourself if it gets too out of hand. They can go ka-boom pretty easily.

Its in the shop? Dang i could have run you through a few things to check before you took it to the shop. Could be a somewhat simple fix.

I think mine will be headed to the shop here soon too. Still having my issues, but i need a scanner and some other "tools" that i don't have to figure it out. I think mine are more oil pressure related, which is not cool.


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## greatwhitehunter (Nov 16, 2007)

Since we're on this topic, I might as well share my problem and see if anyone has a solution. I have an 01' cummings and I just changed the batteries out in september. When the weather turned cold I could not get the truck to start for nothing. Up until this winter, the truck has started up first time no matter how cold the weather has been. My first experience with it not starting was during the elk hunt. Luckily I had a generator and a few hours to let it warm up after plugging it in. I thought it was just the cold and altitude but it acts the same even today. I can cycle the "wait to start" light a couple of times with the same results. Afraid to drive it anywhere far where it will sit for a while and cool off. Any suggestions??


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## phantom (Sep 13, 2007)

When did you last change the fuel filter?


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## greatwhitehunter (Nov 16, 2007)

I changed it 2 years ago when it had 38,000 miles on it, now it has 52,000 miles


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## nickpan (May 6, 2008)

I'd change the fuel filter.

Your fuel heater may have gone out. Check all your fuses. Cold weak batteries or starter starting to go. Grid heater may also not be working.


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## Huge29 (Sep 17, 2007)

Is it safe to assume that both of you guys know to drain your water/fuel separator every once in a while? 
On the last person's issue; what are the symptoms? Cranking and just not firing up or slow crank?


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## greatwhitehunter (Nov 16, 2007)

Cranking and just not firing up when it is cold. I have had it plugged in the last couple of days. The grid heater seems to be working just fine as all the new snow is melting off the hood and it starts right up when it is plugged in. I'm wondering if there is a separate circuit that the "wait to start" light runs through for the battery that might have a blown fuse or bad relay???. The batteries are new in september of this year.


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## Huge29 (Sep 17, 2007)

greatwhitehunter said:


> Cranking and just not firing up when it is cold. I have had it plugged in the last couple of days. The grid heater seems to be working just fine as all the new snow is melting off the hood and it starts right up when it is plugged in. I'm wondering if there is a separate circuit that the "wait to start" light runs through for the battery that might have a blown fuse or bad relay???. The batteries are new in september of this year.


So, if it is plugged in it starts right up, but shut it off and unplug it and it will not start back up? If that is the case, it almost sounds as if the 110v power must be helping to get something going that would make me think there is possibly a relay issue or...??


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## MeanGene (Nov 18, 2008)

OK so here is the latest. 5 out of the 8 glow plugs were bad and both wiring harnesses were rotting. Relay is good but had to also change out the bolts on the battery cables. They seemed tight but were rotted/corroded just enough that it was allowing acid leakage to creep into the contact area. Man it sure was nice to have her fire up right quick this morning without hesitation.   And yes I know it can be dangerous to use starting fluid in a diesel, but if you do it very carefully and only use a very small amount it works wonders.


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## blownsmok97 (Nov 8, 2009)

So did ya get her all done then?


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## MeanGene (Nov 18, 2008)

blownsmok97 said:


> So did ya get her all done then?


Yes it is all done, I just had the shop do it as I don't have a garage to do it in and it's not exactly warm outside right now. However I have noticed the last couple weeks that the lights in my gauges flicker ever so slightly to the rythm of the motor when idling. Any idea what that could be? I'm thinking I may have a grounding issue somewhere.


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## nickpan (May 6, 2008)

Your alternator might be goin downhill. Might have somethin in there not tight or grounding out like you said. Or the belt isn't very tight. COuld also be not charging your batteries enough which will give you starting fits in the cold as well.


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## stuckduck (Jan 31, 2008)

MeanGene said:


> Yes it is all done, I just had the shop do it as I don't have a garage to do it in and it's not exactly warm outside right now. However I have noticed the last couple weeks that the lights in my gauges flicker ever so slightly to the rythm of the motor when idling. Any idea what that could be? I'm thinking I may have a grounding issue somewhere.


the diode's in the alt. are failing.. needs replacing..


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## stuckduck (Jan 31, 2008)

greatwhitehunter said:


> Cranking and just not firing up when it is cold. I have had it plugged in the last couple of days. The grid heater seems to be working just fine as all the new snow is melting off the hood and it starts right up when it is plugged in. I'm wondering if there is a separate circuit that the "wait to start" light runs through for the battery that might have a blown fuse or bad relay???. The batteries are new in september of this year.


You need to check the heater strip. the key with a diesel is heat and fuel. if it starts when plugged in then you have an alternitive sours of heat enough to make compustion in the cylinders.


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## MeanGene (Nov 18, 2008)

I checked at the batteries while engine running and was getting 14.25v is that not correct. I did not check it under load though (heater, lights ect. on) Maybe I will run over to autozone and have them run a check since thats where I bought the alternator from 2-1/2 years ago, New not reman. Belt looks good and tight.


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## Huge29 (Sep 17, 2007)

MeanGene said:


> I checked at the batteries while engine running and was getting 14.25v is that not correct. I did not check it under load though (heater, lights ect. on) Maybe I will run over to autozone and have them run a check since thats where I bought the alternator from 2-1/2 years ago, New not reman. Belt looks good and tight.


As a former Zoner myuself, I can tell you that half of the guys don't know what they are doing there, the ohter half are really good, after testing the charging system with engine running, be sure and disconnet one battery, so that you can test each one individually. Otherwise, they will for sure test good even if one is bad. 14.25v sounds about right.


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## blownsmok97 (Nov 8, 2009)

if your getting 14.25 volts at idle, it sounds like your alt is charging just fine. Check and make sure your connections are tight, no loose cables or grounds or something.


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## MeanGene (Nov 18, 2008)

Had them put there big meter on it and the alt. is fine. Battery cables are good also. Time to start chasing down all the ground spots and make sure there all tight I guess.


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