Runs REALLY rough when cold, great when warm. Glow plug issue?

[DozerF350]

Hi all,

It's been quite a while since I've come to visit over here, mostly because my truck has been running really good. I have a small problem now though. Here are the symptoms.

The first time I start the truck each day, it runs REALLY rough for about 5-10 minutes depending on how cold it is outside. The last few days, it's been 30-40 degrees (F) overnight. If I just let it sit there idling for a while, the problem smooths right out and I don't have an issue again until the next morning. If I try to drive it right away, the truck vibrates and I have no power. I'm pretty sure that's because it's not firing on all 8 cylinders. So my question is, what could be causing this? I thought about just replacing all 8 glow plugs, because logically that seems like it would fix the issue. I just don't wanna spend the money and have it not fix the problem, and have to troubleshoot some more. I'd rather just get this done right the first time.

I haven't tried to pull codes (no scanner at home), but none of the dash lights come on while it's idling. The truck starts up without any issues, even though it runs rough. And like I said, once it's warmed up a little bit, it runs perfectly, really smooth with lots of power.

I have a 2006 F-350 6.0L with no modifications.
I have just over 100,000 miles on it (yes, JUST out of warranty)
I maintain it religiously.

Any help would really be appreciated.

Thanks,
Eli

[Soot_Life]

its just cold.. my 06 6.0 did it every time i showed up late for work.. jump in and drive it ran like crap warmed up it ran fine..

my 7.3 does the same but to a lesser degree.

these motors like cold air going in and out but the motor itself likes to be HOT!

if you have a block heater installed plug that in next time it gets cold out and see if you have the same issue in the morning.

[DozerF350]

Oh, I forgot to mention, it only runs like this the FIRST time I start it each day. I can drive it for 20 minutes, and let it sit for 8 hours, and it'll start and run just fine. It's only after it gets colder at night that I seem to have this problem.

Thanks,
Eli

[DozerF350]

Originally Posted by Soot_Life

its just cold.. my 06 6.0 did it every time i showed up late for work.. jump in and drive it ran like crap warmed up it ran fine..

my 7.3 does the same but to a lesser degree.

these motors like cold air going in and out but the motor itself likes to be HOT!

Yeah, I thought that too. I mean when it got REALLY cold last year (below 0) it ran like this until it warmed up, but now that it's getting into the 40's in the mornings, I wouldn't expect it to run so rough. Also, the problem seems to be getting a little worse the last few weeks. I'll try plugging it in tonight to see if that helps too, thanks.

[Soot_Life]

well living in florida 30s and 40s are dam* cold.. and thats when i noticed it.. best thing is start it let it run 5 minutes before you throw it in gear.

[nylyon]

Have you checked to see if there's any codes? I have looked into this a lot with mine here's what I learned. The bad cold starts have several likely causes. Glow plugs can cause issues like this, but it is my understanding that they will throw a code if bad. Another issue can be a bad FICM which can be tested to see if you have 48 volts during cranking and shortly after starting. And finally, which may be more likely is your injectors.

The spool valves in the injectors will stick after time. This stiction can cause improper fuel delivery to the cylinder resulting in a miss and or smoke. As the engine warms up, the spool valve frees up and the injector begins to fire properly. Ford addressed this by introducing inductive heating on the FICM. This causes the spool valves to cycle quickly causing heat and help to fire the injector properly. You can get your PCM, FICM flashed with the latest code if your truck doesn't already have it.

I have just recently used Rev-X my results are posted here. This snake oil resolved a similar issue on my truck as well as many others. I completely understand apprehension when using oil additives, and I don't know if there will be any long term effects of using this product but the short term has eliminated my issue.

[TXappraiser]

I agree with nylyon. Sounds like you have a couple of bad injectors. My truck had identical symptoms as yours and it turned out being my #2, 3 & 5 injectors. Injectors dont fire right untill oil is warmed up. Got it fixed last week no more problems with warm up. Jus get in and go. good luck

[PGreenSVT]

IF your problem is with injector stiction, which it sounds like, without a doubt 2 bottles of RevX will fix your problem. If your problem is with the FICM, which is easy to check, you should take care of that first. The symptoms are the same so you need to rule out the FICM first. But without question RevX fixes injector stiction fast. Read the threads and see how it has cured the problems for all the doubters.

[DozerF350]

Thanks guys. I plugged my truck in last night, and it was smooth as silk from the get-go.

Question about the injector issue you're talking about. So if my spool valves are sticking, will I need to replace the injectors? Are there aftermarket injectors that will eliminate this issue altogether. I've had injector issues in the past that were covered under warranty, but if I don't have to drop a ton of cash on new injectors, I'd rather not.

I'll do some research on this RevX stuff you're all talking about.

I'll check the FICM this weekend if I have time. Is there a run-down somewhere on how to do that?

Thanks,
Eli

[nylyon]

Let's assume your FICM is good. Yes, replacing the injectors that have stiction issues will fix the problem, but you have other options too. If your truck hasn't been flashed for the induction heating, you can ask your dealer to flash your truck. This may help, heck even fix your problem. If you're not hesitant with using Rev-X, it took only 30 minutes to fix my truck, and for the first time this morning at 29 degrees, it started right up and was 100% drivable, and I'm pleased with the results.