Codycody

Hello everyone! Great forum, tons of great info! This is my first post, and I was curious if anyone would be kind enough to help me troubleshoot my truck. My mechanical level is a 5 out of 10.
a little backstory, purchased the truck about 3 months ago. 2004 super crew, 5.4, newer body style, 315,000 miles(holy crap, right??!!) The truck looks great and ran great until this last week. When I first got the truck, I changed the disgusting oil, and all the fluids, and filters besides the trans. I had a little time off from work, and decided to tackle the front suspension. That went so well, I decided to throw in new spark plugs, and coils...that's where my trouble started..previous to this the truck ran great with no CEL's. Averaged around 17 mpg

I used motorcraft sp-546, and duralast coils. Changing the spark plugs went smoothly, besides a few coil connectors didn't snap in. I haven't replaced the all yet. On cylinder7 the plug was completely rounded off! I didn't want to make it worse so I decided to leave it as is and let my dad help me get it out. He's an old school mechanic with tons of knowledge. After getting new coils and plugs in I had a misfire! So I drove around until a CEL popped on. P0352. I figured it was a loose coil connector. Popped a new one on and still misfiring! Same deal, drove around until the Cell popped on and P0357. So I replaced that connector. Still misfiring. Did the same thing and now it's back to P0352. I believe cylinder 7 is the one to blame. While idling I called pull the fuel injector connector with no change to misfire.

Sorry for the lengthy post!

Codycody

Also, I did try swapping a different brand new coil on to these cylinders with the same result. Also, I don't know if I did it right, but while running I read cylinder 7 wires, 13.8 volts on the hot side and -2 up to 2 on the ground side. It was all over the place

F150Torqued

The 5.4 3v is VERY PICKY about spark plug jobs. They have to be done 'Hospital Operating Room clean', or you'll have misfire headaches. My guess is you have fallen into one of the typical pitfall traps. COPs "SELDOM" go bad, and many have head aches with aftermarket. I don't know if this contributes - but very well could. OEM are best.

We here at this forum have also seen "NEW" spark plugs bad - right out of the box. But almost more likely is the special plug design with the long electrode extending down into the head - and carbon buildup in that extended hole in the head. Carbon build up in that area can fracture new plugs on re-installation (ruining an otherwise perfect new plug). You might get something out of my misfire experience posted here. https://www.f150forum.com/f4/5-4l-3v...6/#post3930018

Definitely the COP electrical clips are important and fix any one that don't properly 'snap'. Also VERY important (more than COPs) are NEW BOOTS, and a small dab of dielectric grease inside the plug end to keep moisture out. Make sure the contacts (and spring contact points) are clean. Be aware, electircal connection problems result in P035x series codes. P030x codes are 'actually' the result of an absence of crankshaft acceleration following the computer sending a spark command to the COP - (by grounding the control wire on the COP).

Codycody

Thanks for the reply my friend! What you're saying makes sense. The plugs all screeched like hell on removal. They were extremely worn out. I blew out each hole with compressed air prior to removal.

I do remember thinking the plugs did not go back in smoothly. Like a quarter turn in it felt "gritty".

I will replace all coil connectors and try replacing cylinder 2 plug with another new plug after I clean the carboncbuild up let you know my results!

dukedkt442

I had a Duralast coil fail within 200 miles of installation; since then, 10k miles without a COP issue (and if there were, they have lifetime warranty... never have to buy another one).

Check plugs again. Pipe-cleaner to clean out the hole for the electrode.

I didn't have a misfire at all, but the occasional lean-code (every few hundred miles). I checked all plugs, and when I got to the 6th plug (cylinder #2), I found water above the hex of the plug. Most guys say these need to be "hospital clean," and I myself will say to also go as clean as possible... but from my outlier, if the truck can run with no misfire with both the boot and plug submerged in water, it may not be as finicky as believed.

Your mileage has other concerns: what's the history of its timing components?

Codycody

I have no clue the history of timing components. I do have a cam phaser noise. I have the full timing kit and new oil pump, but I have to get time to install. I may have a professional do it if I can find one.

dukedkt442

I'm of the "little nickle antiseize" camp: on the part that extends into the head (beneath the threads) and a light smearing on the threads themselves to lubricate them going in and avoid cross-threading. Antiseize is electrically conductive, so within reason, should only be a benefit.

As for timing... Melling pump? Most here swear by those. The phaser knock is your "canary" telling you that you have low oil pressure, either due to wear, soft pump, or bleeding chain tensioner (or all three). You don't want to let it wait, especially at your mileage. Use Ford parts, should run around $1400. If using cheaper parts, prepare to pay at least that, perhaps double, not counting all the revisits. It's not a hard job, but technical (it is a Ford, afterall). Check Ford Tech Makuloco youtubes on his 4 part 5.3 3v timing rebuild... don't forget to pull the pan to pull all the remnants of the worn chain guides out of the oil pump pickup. If you can do plugs on this truck, you can do the timing, especially with a "learned mentor." Becareful if using the valve spring compressor that you don't drop a valve... I never had a problem (but puckered the entire time), but others have, and then it's a world of hurt. Any questions just ask, folks here are a well-learned bunch.

F150Torqued

You found them already. It's just that they are all on here - and only do the job on their own trucks. As far as finding a mechanic that will do the job "RIGHT" for you - I'm at a loss.

dukedkt442

Paying for labor for a timing job on a 350k mile truck would exceed the value of the truck and not financially worth it, IMO.

Codycody

I understand what youre saying but, I'd like to get a couple years out of this truck and if that costs me a couple thousand, then that's what I'll do.ive watched some videos on how to do a timing job, and it's not nearly as bad as I imagined. I've done all the work on my Fox body but that's a pushrod engine, so originally it was a little intimidating with the mod motor. I definitely don't want another note. I like the idea of having an older truck, where if someone dings the door while grocery shopping it'll make no difference to me. Before I do anything though, I need to get the misfire fixed. I really think it's an electrical issue