5.4 issues - misfire
 

Have a 2006 F150 FX4 w/ 108k miles on it - seems to have gone down hill quick recently. Had the pinion bearing start whining, ended up finding a rear end in the junk yard and replaced the entire axle.

Prior to that replaced the spark plugs with Champion 7989 and replaced the COPs. All was good until had a loss in power and throwing a code. Turned out that one Champion was bad...all was good once fixed.

Back to now...changed the rear end out....needed to get the XL3 additive at the Ford Dealership. In the dealership parking lot the check engine light came on (WTH)? Running okay with a slight miss at acceleration...code was P0605. Cleared it, came back, low on power at acceleration (past 50 mph). Ended up carrying it to the dealership. They reflashed the ECM, said was all good, idles good...took it home and opened it up on the road and still have terrible miss at speed over 50 mph. No codes are being thrown.

I have smelled gas at times and I'm hearing that some plugs may have backed out.

Thinking of replacing the plugs again...only have about 2000 to 3000 miles on them.

Going down the right path?

Sounds like you are on the right track.
I'd only ever recommend motorcraft plugs (Motorcraft SP515). There are some mixed results with the champion plugs in terms of how long they last- so it seems like a gamble. There are very few people who have issues with the motorcraft plugs.

Also dont forget to apply nickel to the shank (not threads) to prevent carbon buildup to make future removal easier.

The sooner you fix the missfire the better- It will eventually clog up your catalytic converters and if your new COPs are shorted from a bad plug / connection it will wreck those in short order as well.

Theory on 5.4l random misfire
 

TO ALL 5.4L 3v owners: :fyi: :surrender:

I HAVE NEVER seen this mentioned relating the random misfire problem to the spark plugs breaking off on removal - but it makes sense to me.

About three years ago, a random misfire developed on my '04 5.4L 3v under light acceleration (45-55 mph) at about 110k + mi. I fought the problem for two years / 60k mi. Replaced a bunch (finally ALL) COPs and spent 200 hrs labor swapping, changing other parts, talking to mechanics and reading posts. Changed spark plugs TWICE during this time. Broke five the first time and two the second time and they all sounded like removing rusty lug nuts when removing them. Neither plug change helped the misfire problem, just moved to different cylinders.

One day I decided "IF THE CARBON BUILDUP AROUND THE SPARK PLUG IS SUFFICIENT TO TWIST THE ENDS OFF UPON REMOVAL - HOW THEN CAN I EXPECT TO SCREW A NEW PLUG BACK IN THAT SAME HOLE WITHOUT DAMAGING THE SNOUT ON THE NEW PLUG OR "FRACTURING" THE CERAMIC INSULATION INSIDE THE SNOUT?" I had to use a ratchet with some significant torque to screw new plugs in. --- Perhaps, the carbon buildup in the spark plug hole was breaking/damaging new plugs on re-installation - just like it does on removal!!


I had never read a TSB or post talking about this possibility. So I bought a (third) set of new spark plugs (Motocraft SP515 this time) and spent $19.99 on a set of steel thread brushes, (similar to bottle brushes) with a "T" handle, from Harbor Freight. While replacing the plugs this time, I rotated the engine to TDC on each cylinder in turn, and took the steel bottle brush (about the size my little finger) and cleaned the carbon out of the spark plug holes beyond the threads until a carburetor soaked rag would come back perfectly clean!! If not, I'd burnish the heck out of that hole again. When I got through, the new spark plugs screwed all the way down to the seat with my fingers just like putting them in a new engine. Then torqued them down appropriately. Upon startup, INSTANTLY - BINGO - perfect startup, idle, and now a 100,000 miles later - with one more plug change done the same way, not a single misfire. My OBD II diagnostic tool indicates ZERO misfires on all 8 cylinders in the last 10 drive cycles. At 206,000 its a perfect pleasure to drive - gradual acceleration is perfectly smooth until it shifts down and goes on like it did when it was new!!!!

IMHO, I believe MANY MANY people (mechanics) damage new plugs on re-install because of binding in the same carbon buildup that seized the old plug and broke it off during removal. I've seen mechanics remove AND reinstall new plugs with an impact wrench. And on my first plug change, even I 'torqued' the new plugs in with a ratchet - with them "screeching" like hell. If the old plug was seized in the head with carbon when removed / the carbon would have to be binding on the new plug enough to crack the ceramic inside the plug, leaving it susceptible to arcing over inside. I'm fairly convinced this is why my first TWO spark plug changes did nothing but make the random misfire or intermittent misfire move to different cylinders.

IF THIS THEORY IS CORRECT, THEN THE FURTHER QUESTION IS. Why does the random misfire begin in the FIRST PLACE before the first plug change?

What is the "reason for the long reach plug design" in the first place? (Not trying to justify Ford's screw up, but "Where is the benefit"?) They certainly could have just moved the plug threads down closer to the combustion chamber and used standard plugs or used some existing longer threaded plug.

I recall from my hot rodding days that "Hotter plugs" operate more efficiently. Resistance goes up as temperature goes up. Higher temperatures (thus more resistance) on the anode & cathode require higher voltages to produce the spark. The higher voltage potential across the anode/cathode gap ionizes the combustion gases better so the spark can jump a wider gap. This higher voltage & heat range is also the reason 'palladium' plugs are recommended. They'll better tolerate the violent high voltage spark and the higher temperatures. Certainly the "1 inch snout" on the plug protruding down to the combustion chamber would reach temperatures almost equal to the combustion chamber itself. ---- THAT IS IF THE SNOUT IS NOT IN CONTACT WITH THE CYLINDER HEAD - which is constantly cooled by the water jackets.

IMHO, the CARBON BUILDUP that seizes the plug snout (and it certainly is in contact when the plugs are seized - EVEN after a plug change), would conduct heat away from the plug tip into the cylinder head & water jackets. I believe this slight "threshold" effect may explain why so many people report intermittent, random misfire or " bucking " under light load at low RPM (45-55 mph), with NO code set. [This operating range also happens to be where MAXIMUM phaser retard is applied, which further leans the fuel air mixture with recirculated exhaust gases!!] Perhaps because it is a "slight threshold" issue with the ignition process, the spark process needs to operate absolutely "PERFECTLY". changing COPs, running higher octane fuel, VTC Solenoids, and a variety of things _seem_ to help, causes the random misfire to move around, but doesn't cure the miss.

It is certainly TOO simple to clean the carbon out while changing the plugs. So simple - it sounds stupid. This is why I'm surprised its never been mentioned in a TSB or post dealing with this issue.

PS: Caution must be used to NOT drop a wire brush bit into the cylinder. With ALL plugs removed, it is a good idea to rotate the engine where each cylinder in turn is at TDC while it is being cleaned.


Just my thoughts (shade tree opinion) on the problem. Hope it helps someone. :beers:

To add - always use high temperature nickel antiseize on the plug barrels when replacing them. It also helps a lot if you run a few bottles of Techron through the gas before changing them.

NO, NOT antizeize ????
 

@glc

With all due respect to my Senior Member, and full disclosure that I am in no way an expert - just hyper analytical -, do you disagree with the second part of my theory concerning the intent of the plug design on the 5.4L 3v? Or, do you feel that nickel putting antiseize on the plug barrels would not appreciably promote heat transfer from the plug snout into the heads? And, do you feel the antiseize compound (even high temperature) would survive the combustion temperatures so as to not turn into caked deposits itself?

It appears to me that the clearance between the barrel and the head in the plug cavity must be on the order of 10 to 20/1000ths. Even applying a "thin layer" of antiseize would almost certainly fill that space on install and provide (metallic properties) heat conductivity - which would tend to defeat my proposed design purpose. I do not disagree with putting antiseize on the "plug threads", but only on the barrels. It might make them easier to remove, but more susceptible to the misfiring problem under very lean conditions and light load - IF MY THEORY HAS ANY MERIT. Would it be better to just remove the carbon each time - and of course change plugs more frequently, perhaps every 60k miles?


Again, I respectfully debated long and hard :goodbad: about this challenge to putting antiseize on the barrel. But it is an important part of the discussion and I would respectfully like to hear your analysis. :scared:

Ford RECOMMENDS the Anti seize to aid in the removal of the plugs the next time. Beyond that if you dont want to use it, whatever.

Ford has revised the TSB for plug removal in the 3v heads a few times, but each and every one of them require the use of high temperature nickel antiseize on the barrels and NOT on the threads. Professional techs here also say that the use of Techron in the gas for a few tanks prior to the plug change makes removal easier.

May I suggest you spend some time searching the many threads here on 3v plug removal?

Spark plugs electrodes typically run at 500 - 850 C, any less than 500 and you get baked on deposits. Having the nickel in place acts like a non-stick coating so that deposits wont be charred into the plugs.


Unless your are running a jet engine, temperatures will never get hot enough to burn the anti-seize off.
Taken from permatex website:
Nickel Anti-Seize Lubricant
Protects metal parts from seizing and galling at temperatures up to 2400°F (1316°C). It is recommended where copper contamination must be avoided, under conditions of extreme pressure and temperature, and with stainless steel, titanium and nickel alloys. - See more at:

http://www.permatex.com/products-2/p....5YYdRBlY.dpuf

Make sure you don't have any moisture around the COPs - if you do, an intermittent miss will develop especially when the engine gets hot, and while under load trying to accelerate - see this several times.

5.4L issues - misfire MORE ABOUT THAT
 

I thank each of my fellow members for their good thought provoking responses - and EXCELLENT fact links. I reply without malice intending only to promote more good, analytical discussion on this thread's subject of'5.4 issues - misfire' and be helpful to the thread author and others with the same problem. I realize I injected the subject of "spark plug removal" into my original post #3, however that is really a different, (although important) subject. My focus was more about "PUTTING NEW PLUGS IN" and how that relates to the misfire issue - specifically by affecting the plugs "heat range".

https://cimg1.ibsrv.net/gimg/www.f15...da24d8aa39.jpg

Spark_Plug_Heat_Range_Chart from the NGK website

That post led to the anti seize issue. Given the clobbering I got from @GLC about "reading up on PLUG REMOVAL", it's a darn good thing I had hid under my chair after post #5. :scared: But be assured, I've done plenty of research on plug removal, and have survived initiation into the "Plug Removal Club". It's just that I don't immediately believe everything in print (including posts unsupported by fact -or for that matter - even TSB 08-07-06 https://www.f150online.com/forums/v8...ml ). I would wager that @GLC nor most others who advocate application of anti seize do not adhere to the TSB's recommended procedure for removal of the porcelain in failure mode 3 --- https://www.f150online.com/forums/v8...ml#post3146015 - like in this photo

https://cimg2.ibsrv.net/gimg/www.f15...f718245043.jpg

The TSB's failure described as Mode 3

As for @jethat's suggestion that anti seize aids in subsequent plug removal....... .....there are more than a few posts out there (based upon personal experiences) stating the application of anti seize doesn't aid in plug removal the next time as @jethat
(and the TSB) suggests. Such "reading up" does not appear to confirm it as expressed in the following linked post. DON'T BELIEVE IT. See: Followed TSB - "WITH HIGH TEMP ANTI-SIEZE" !! http://www.ford-trucks.com/forums/11...l#post11799905 . of which 6 of 8 turned out like this:

https://cimg5.ibsrv.net/gimg/www.f15...53d662aad6.jpg

Plugs removed after application of anti seize compound according to TSB 08-07-06

I would like to hear from others who have followed TSB 08-07-06's anti-seize recommendation and tell us "HOW THAT's WORKING OUT FOR YOU? "DOES ANTI SIEZE PREVENT PLUG BREAKAGE ON SUBSEQUENT CHANGES?" And "DOES IT HELP CURE MISFIRES?"

It is my opinion the unique design of this spark plug --

https://cimg1.ibsrv.net/gimg/www.f15...d4cec9403f.jpg

Motorcraft ACF-515

had a specific purpose for use in these engines and the unintended carbon deposits coming in contact with the long electrode shell exacerbates several operating conditions that leads to misfire issues. Ford could have simply used a longer thread plug, such as:

https://cimg6.ibsrv.net/gimg/www.f15...5dbd089b7a.jpg

Regular long thread plug

But the 5.4L, 4.6L, and 6.8L (3v) engines, with SOHC variable valve timing are designed to run lean, at low RPMs, and use valve retard to meet emission standards and power requirements. Under low RPM, light load, valve timing is at maximum retard - (regurgitating exhaust gases like an open EGR). Vacuum is low and the IMRC swirl control valve is fully CLOSED trying to better atomize fuel in the slow moving intake air. Ignition timing is retarded to near 0º to avoid pre-ignition. ITS A PERFECT SCENARIO for misfires if _EVERYTHING_ IS NOT OPERATING PERFECTLY. Upsetting the "heat range" of the spark plug is simply another aggravating condition for misfires. (ie: as @asbennett aptly pointed out in post #9"), so is moisture in the COP boots - - The same thing applies with failure to use dielectric grease.

It is my understanding, (although I have not been able to verify), that the SP515 Spark Plug has been redesigned with a smaller barrel with more hole clearance in an effort to prevent the carbon deposits from coming into contact with the barrel - and hence seizing. See Photo below is supposed to be the "original" alongside the "new".

https://cimg2.ibsrv.net/gimg/www.f15...c49476e390.jpg

Old vs New SP515 ??

But they STILL seize! Especially if the change interval is excessive (_without removing the carbon build up_ at some point). @shoon makes a good point about the anti seize, supported by a good link: , is correct on both counts confirmed by the Permatex link, and further confirmed on the NGK site http://www.ngk.com.au/spark-plugs/te...ng-temperature .

https://cimg5.ibsrv.net/gimg/www.f15...847ace4500.gif

NGK plug operating temp chart

(put in layman's terms that even I can understand, 500ºC = 962º F, 850ºC= 1562º F) That would be referring to the "barrel", or the "snout" as I call it, on the uniquely designed SP515. See SP515 - the first photo above).
Unfortunately though, the carbon deposits are not adhering to or accumulating ON THE PLUG BARRELS. It builds up on the surface inside of the holes in the head, until the entire clearance is filled with carbon deposits. This surface is, by design, cooled by the cylinder head water jackets and operates at MUCH lower surface temperatures, (well below the 450º "fouling area" shown in the above photo). Once this accumulation of carbon deposits come into contact with the ground electrode shield - it provide an unintended heat conducting path "AWAY FROM" the electrode into the metal shell, the cylinder head, and ultimately the water jackets. This alters the "HEAT RANGE" of the plug. See diagram below:

https://cimg1.ibsrv.net/gimg/www.f15...7a24096d1a.png

NGK heat dissipation path

This heat dissipation away from the electrode delays and prevents the electrode from reaching proper operating temperature, or proper "HEAT RANGE" where it operates most efficiently. Apparently expansion / contraction of the deposits from multiple drive cycles "packs" the stuff in there hellishly tight. Ultimately, the carbon deposits result in the "snout" becoming seized in the head - so tight the snout twists off!. WTF. Fellow members have placed plugs in a vice and tried to twist off the barrel, reporting great torque is required. @Jim Allen reports it took 36ft lbs of torque twist the electrode barrel off !!! ..... See http://www.ford-trucks.com/forums/11...l#post11051271 NOTE: The TSB 08-07-06 reports on Page 2 that 33ft lbs of torque may be required to remove the plugs - AFTER following the recommended 15 minute soaking with "Motorcraft Tuneup Carburetor Cleaner"! Application of anti seize is total BS! Might as well use axel grease. It is my firm conviction - when the plugs are seized in the head, if the carbon deposits are NOT removed before re-installation of new plugs, YOU WILL fracture/damage the porcelain in the electrode of the new plug setting yourself up for continued misfire issues. The engine will run but, under extreme conditions, spark will arc over in the cracked or fractured porcelain around the electrode. That leads to unburned fuel to the O2 sensor, which leads to upsetting fuel trims, which leads to flashing MIL and CAN lead to catalysis inefficiency codes.

As for "PLUG REMOVAL", My thoughts on are: TSB 08-07-06 is stupid. And anti seize is BS. :lies: If a plug breaks on removal, the Lisle tool works magnificently. But Ford should NEVER have recommended 100k mi plug change interval. On a more reasonable interval of 50K to 60k - it is my opinion the plugs would most likely NOT be seized badly enough to break off on removal -- PROVIDED HOWEVER that the carbon is cleaned out and not allowed to build up (as it inevitably will). This should have been a normal part of the plug change procedure specified (just like anyone would do the pistons and head while replacing a head gasket). That's the F150Torqued TSB on Plug Removal and reinstallation.

Now, I go crawl back under my chair! :scared:

Ford also designed the system that is causing the broken plugs in the first place, so I personally take their "recommendations" with a grain of salt.

It seems to me that a fuel additive that prevents carbon build up would be beneficial.

What fuel additive will "prevent" combustion carbon buildup?
 

This I would whole heartedly agree with, for more reasons that just preventing spark plugs seizing in the head. But I know of none that are truly effective or safe for CATS if using it all the time. I think just the oil vapors that are drawn through the Positive Crankcase Ventilation system into the intake manifold - over a period of 90-100 k miles would be enough to carbon up that .010 to .020 inch gap around the 5.4l 3v plug electrodes.


JMO

@F150Torqued; dude, don't go hide under a chair... keep on investigating. It's people who are brave enough to challenge the main stream "opinions", that end up changing the main stream opinions.
There is simply no substitute for experience and accurate research, as in your case. IMHO, I have had enough of folks who just repeat what they hear without any kind of personal experience to add. Then sooner or later folks believe what most folks are saying, when most of it has no real basis.

Having a degree in Mechanical Engineering for over 20 years, as well as building cars for about 40 years, I agree with your carbon buildup suggestions. I think it is something like what you are suggesting, which is causing the floating misfires on higher mileage 3V motors, built prior to the plug change in 2008. Plus when I followed your recommendations the plug change was much smoother to accomplish.

What I'm trying to figure out is if all of the carbon buildup is acting like more of an insulator or a ground, either causing a colder plug by pulling heat away quicker... or a hotter plug by insulating the plug more and retaining the heat. I guess either way, the plug is not operating as intended, which could be what we are all chasing.

I know that when I recently changed my plugs... again...I noticed the plugs looked like they had far more mileage on them then they actually did. The electrodes were really worn out and they had a lot of fouling on them. I had about 30K on them. So again, I think you are on to something.

Keep up the great work!
Thanks.

A sincere thanks
 

@rocket_man


Thanks for the flowers. Coming from someone with your credentials means even more. A background rooted in electronic engineering and programming made me hyper analytical. The majority of my engine experience came from hot-rodding and supping things up in my high school days - in the 60's.


Recalling how 'rock hard' that ole combustion chamber carbon was when rebuilding heads back then convinces me that many new SP515's are cracked or fractured inside by forcing them back into those carboned up holes in the 5.4l head. Hell, I recall chipping that crap off around the valves with a hammer and screw driver. We didn't have the solvents of today (like Techtron), but I know kerosene wouldn't do much to it. You gotta' admit that ***** is really packed in there around the barrel of the plug for it to "twist" the barrel completely off comming out.


The "hemi" style design of the 5.4L head may contribute more to the pushing combustion contaminates right straight up in that hole around the barrel of the plug?


https://www.f150online.com/g/picture/4504569


For whatever personal experience is worth - (and I think it's a lot), I "had" lots of trouble with floating misfires on my 2004 5.4l Triton - under "light load"/ "light acceleration around 45-55 mph for a long time. Ever since ever I adopted the technique of cleaning the carbon out at each plug change - I have had NONE. Seriously - my Torque Pro app Mode $06 reports shows NO misfires in the last 10 driving cycles. After having changing all kinds of stuff to no avail, I cannot attribute the fix to anything else.


Thanks again for listening seriously.

Coolant leak fouling plugs
 

@ Chalk
I had the same misfire issues with my 07 F150 2 weeks ago but I could smell coolant burning. I pulled the code and told me which cylinder was misfiring, pulled the spark plug to find it was fouled with what look like oil but was actually burnt coolant. I looked around and found the coolant leak at the thermostat housing base (the aluminum waterway between the thermostat and heater hose), where coolant was running back along the spark plug rail. I figured it was the rubber gaskets under the waterway, so I pulled the intake manifold and removed the waterway to find a chunk of plastic missing from the intake manifold that was allowing the rubber gasket to collapse. Anyway, had to replace the intake manifold to fix the leak, cleaned up the spark plugs (spark plugs are only 3 months old), and truck runs good as new... Could be something to check for leaks causing issues with the spark plugs.

about the misfire
 

So, I battled a misfire for about a year and a half before figuring out the simple cause of it. I pulled up and down on all of the coil packs without even unscrewing them to make sure they had a good bite on the spark plugs in case there was some buildup, (they still have some play when they're screwed down) and I have been good for about 5 months now. After replacing the fuel filter and doing fuel treatments, replacing one coil that threw a code (twice in the course of a year and a half it actually misfired bad enough to throw a code, the rest of the time it was just an intermittent sputter while cruising, poor mileage, and a slight rumbling while accelerating) and every other inexpensive thing I could think of trying. I refused to start replacing injectors and coil packs and spark plugs when they actually looked good and I had no real evidence of what was bad. I just dealt with it hoping it would become bad enough to throw a code, which only happened once and the issue never really got worse. So on a whim I decided to reseat all of the connectors on the coil packs and injectors, then I thought about carbon buildup tween the coil packs and spark plugs. That's it, I just wanted to share my experience of the stupid, $0.00 repair that was the culprit of my misfire... A bad connection due to carbon buildup.

@coupedehille


Thanks for sharing your success story - one of the 'umpteen' things that can result in a misfire on the 5.4s that isn't even a spark plug or COP. I bristle every time I read a post that JUMPS immediately on advising "replace the COPs". If the poster takes the advice - he spends a load of money and either still has the problem - or 'inadvertently' corrects the REAL problem (like yours) without ever knowing it. Then goes out and perpetuates the "REPLACE THE COPS" story.

@F150Torqued

Thanks for your great posts. I'm going to do the spark plugs on my 2009 f150 with the 5.4 v8.
What are your thoughts on the NGK 5507 double platinum plugs or the NGK 1698 single platinum plugs vs the motor craft SP-509? These both show as an oem replacement but I'm seeing lots of posts saying to just stick with the ford motor craft parts. I know Autolite manufacturers plugs for ford but they don't have a cross reference for the SP-509(12mm thread diameter),closest is the SP-507 but it's a different diameter(16mm).
The dealer here wants $23 a piece for them here in Canada. The dealer quoted me $350 plus tax just to swap out the plugs,another dealer wanted $500. I'm going to do it myself and clean out the carbon as you did. Just curious if anybody out there has had good results with the NGK's in their 2009-2010 5.4 engines? I see the gap spec as you stated is between .039-.043, The SP-509 comes gapped at .041 and all the oem NGK's are showing .045 I'm leaning towards just getting the motor craft ones but was wanting anyone with experience to chime in.
My truck is sitting at 199,000kms, it's running a little rough under load(not towing),not really missing but a sort of sputter between 1900-2300 rpm's. I'm hoping plugs may smooth it out?
I bought it used with 190km's ,have been driving it since nov/2015 and am pretty sure previous owner didn't do anything but oil changes to it. She feels a little tired.

Thanks guys

Rockauto.com ships to Canada. SP509's are $11.07 CAD plus shipping. If those are original plugs in it, they are very overdue.

@glc
I'm not sure if the plugs in it are original,I am guessing they are and am hoping that is the issue with the roughness/sputter under load.
I have spent a lot of money on it to get it freshened up:
Brakes,tires,shocks,tranny fluid and filter replacement,synthetic oil change,brake fluid flush, a few pulleys and belts replaced, new battery, RH blend door actuator, pax seat frame and motor,windshield, heater blower motor. All in it's north of $4500.
I ordered the motor craft SP-509 from rock auto.com today(thanks for that) and will post my results after I complete the job.
Any other ideas as to what may make the old 5.4 run better? ( don't say get an eco boost or the 5.0)

If it still runs rough after changing the plugs, you may need some coils.

Thanks for the advice. It may be a few weeks before I get the plugs and get it done. Hopefully it's just the plugs.

We will see?
I'll let you know how it goes.

Hello,
I've got 2009 F150, 5.4 L engine with 199,000kms(123,652 miles).
It idles fine both cold and once warmed up.
It seems to sputter slightly under load between 1600-2000 rpms. (This is while going up a hill empty.)

I've changed the plugs, done a coolant flush,tranny flush with a new filter,cleaned the MAF and the throttle body. Fresh oil change and transfer case oil. The truck has an AFE cold air intake as well as a cherry bomb cat back exhaust system. I've had the truck for 1.5 years and got it with 180,000kms. It's got a solid maintenance history with regular oil changes.
I cleared the PCM'S memory after doing the throttle body by disconnecting the negative battery terminal and adding a jumper cable to the positive and negative cables and letting it sit for about five minutes. Reconnected everything and let it idle for about twenty mins to reset the idle limits of the throttle body. I basically followed Fordtechmaculoco's you tube videos for that:

I also used his youtube videos for the throttle body cleaning and coolant change.


I'm not getting any codes. I did get a code about 9 months ago but it's not there anymore and I can't remember what it was exactly...I think it was airflow sensor or something?
The only thing I still plan on doing is the front and rear differentials but I don't think that will have an impact on this weird issue.
I don't know what else to do?
Could it be dirty injectors?
I just put a bottle of lucas upper cylinder lubricant with injector cleaner yesterday and need to run it for a few days and see if that changes anything. I'm still getting that weird stutter/hesitation between 1600-2000 rpms when it's under load. It's not that noticeable but it's definitely there. After all this maintenance I've done it does seem to run a little bit smoother and the tranny seems to shift a tiny bit smoother. I'm out of answers.
If anybody has had a similar issue and was able to fix it,please let me know.
Cheers everyone.


Any other ideas or advice would be great.

Here are the other videos I found very useful.
This guy is great and he was a ford tech for many years,he's got his own shop now and drives a ram ecodiesel, go figure?

Did you replace the coil boots when you changed the plugs? Did you use dielectric grease?

I did use dialectic grease but did not replace the boots. They looked to be in good condition,the plugs didn't even look too bad. I was able to get the maintenance history as well....some of it anyways. The plugs were replaced once before at 90,000kms. So the plugs I removed had about 109,000kms on them. I'm thinking it may be the injectors but I'm not sure how to get at them. Is it safe to spray them with throttle body cleaner or should I use the MAF sensor cleaner?

Neither. Use Techron in the gas and/or pull them and get them bench cleaned and tested.

@glc
I'm first going to attempt to do a resistance test on the injectors as well as the COP's.
I know this doesn't give me a complete diagnostic as it's just a static test but it might show if something is off in that area of OHM's. Unfortunately I don't have a scan tool capable of doing a power balance test.
I don't want to start replacing injectors or COP's unless it's necessary as I'm already knee deep in spending and want to curb that part.

PS: How did the clutch job on your buddies truck go. It was a clutch wasn't it?

Thanks again for your suggestion. I'll try cleaning and/bench testing them if the resistance is bad in any of them.

oh and buy locktight..put it on inside of thread and outside of thread..that keeps it from blowing out and leaving thread in the head..that is another bag of worms.

What on earth are you referring to?

Add me to the list: 2013 Lariat with 52k now. Already had the system recharged 2k ago. It is at the shop again today.

What are you referring to? This is a thread about a 5.4 misfire.

My fault. I was on another thread and I replied to the "related threads". Sorry, disregard please.

I too have been studying on this, and I understand the length of the porcelain from plug tip back upwards to where it spreads to outer plug nody is the determiner of heat range. But all that is inside the lower barrel, any plug when installed and torqued in place in a head has it's body thus virtually become as one with the head metal … be it aluminum or cast iron, etc. It then transfers heat to that head. I believe it remains the length of the porcelain inside the barrel that controls heat transfer rates from plug tip to plug body, and thus head … thus setting or controlling heat range at plug tip. A shorter path leads to cooler plug tips, longer leads to hotter.

I don't think deposits on the plug well wall and lower plug barrel will affect heat … but if bad enough, excessive buildup may well pose a risk to a new plug being snugged into place.