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Need help with Ford 5.4 misfire

TRD270

Web Wheeler
Location
SaSa Sandy
Hello people wanted to see if we had any Ford guru's that can help me out. 2000 Ford F150 5.4 2v gas only motor 130k on the clicker.

Developed a misfire on #3. Gives me P0303 code, i've had P0300 once but it has never come back.

Now I don't drive the truck a ton but it never seems to come on after clearing when I'm just driving around town.

The first time it did it was on a drive to Provo on the freeway. I cleared the code drove around town several times never popped back up. Next time I drove it to Bountiful I came on again. Cleared it, more around town nothing. Same thing next time I drive to Bountiful. See the trend? Seems to only come on with freeway drives.

So not knowing the history of the truck as i've only had it a year. I assumed it was fairly well maintained as it had numerous records on the carfax from general service stuff. I figured the spark plugs had probably been done.

So I start poking around the coils. I notice 3 of the coils had been replaced and the other 5 are original, to include the cylinder i'm having issues with. So I pick-up a new Motorcraft coil throw it on. Head back to Bountiful and boom comes on again...... So now i'm thinking well maybe the plugs haven't been changed. Plugs are cheap so I order a set, as well as coils for the other original ones. Figured have it apart may as well replace them.

Tear everything apart only to find what looks like pretty damn new Motorcraft plugs in it. Electrodes are not worn and all at the correct gap. So 8 new plugs new coils. Take my trip to Bountiful..... comes on again. So now i'm thinking bad injector.

Injectors aren't super expensive so I pick one up. Again Motorcraft. It arrives today, get it installed take my freeway test. My friend P0303 again. So now bad things are running through my head. I borrow a compression tester from a friend since mine was stolen (thieves suck). Don't wish to pull everything, yeah yeah not the best test but I just wanted a comparison.

Compression is great tested 1, 2 and 3 the compression was the same as #1 and higher than #2.

So now i'm at a loss. And open to suggestions
 

DAA

Premium Member
Supporting Member
I think a leak down test would be a good piece of data. My Jeep compression tested great but a leak down test showed my misfire issue was a leaking exhaust valve.

Can borrow my leak down tester if you want.

- DAA
 

moab_cj5

Well-Known Member
I had a 2005 Expedition that developed a misfire. I replaced plugs twice, and coil packs once. Compression came back fine. I concluded it was likely the ECM. I opted to sell the truck at that point and not pursue nor spend anymore money on it.

Good luck in your quest!
 

TRD270

Web Wheeler
Location
SaSa Sandy
I think a leak down test would be a good piece of data. My Jeep compression tested great but a leak down test showed my misfire issue was a leaking exhaust valve.

Can borrow my leak down tester if you want.

- DAA

I was actually thinking just this, i'm worried its a burnt valve. Will you PM me your number? I don't believe I have it. I would like to at least explore this before I take the subsequent posts actions which is about where I am.
 

Gravy

Edd China of Dirtbikes
Supporting Member
Have you checked wiring continuity to the coil pack? Or a folded pin at the coil pack connector?

There's an outside chance that the new coil is bad. Try swapping the coil and see if the problem follows the coil.

I had that error once on my 2001 F250 but a new plug and coil fixed it.

Good luck
 

TRD270

Web Wheeler
Location
SaSa Sandy
Have you checked wiring continuity to the coil pack? Or a folded pin at the coil pack connector?

There's an outside chance that the new coil is bad. Try swapping the coil and see if the problem follows the coil.

I had that error once on my 2001 F250 but a new plug and coil fixed it.

Good luck
I intended to do this when I did the compression test but spaced it until it was put back together as I was trying to hurry and get the tool back to my friend. I'm going to swap it when I do the leak down test. (hopefully I'll remember this time)

When I drove the truck this morning it started making a pretty loud knock. Not like a rod but definitely a knock. It stopped after a short run and giving it a bit of RPM.

I'm wondering if it may have a sticky valve. It wasn't running rough when it was making the noise. I don't have a ton of miles on this oil change but I'm not sure what kind of oil the stealership used when I bought it. I'm going to run some cleaner through it, flush it again with some cheap oil then put the good synthetic stuff I have waiting for the next change in and see if that helps at all.
 

Gravy

Edd China of Dirtbikes
Supporting Member
Was it cam phaser noise? Kinda sounds like a knock. Pretty common on these motors and louder when really cold starting until hot oil pumps up in the top end, especially if it's sat for a while. 5w-20 is spec. But I found that a full synthetic I could run 0w-20 in the winter or a quart of Lucas and virtually eliminate cam phaser tick.
 

TRD270

Web Wheeler
Location
SaSa Sandy
Was it cam phaser noise? Kinda sounds like a knock. Pretty common on these motors and louder when really cold starting until hot oil pumps up in the top end, especially if it's sat for a while. 5w-20 is spec. But I found that a full synthetic I could run 0w-20 in the winter or a quart of Lucas and virtually eliminate cam phaser tick.
Do the 2v's have cam phasers? I thought those were just on the 3v's
 

TRD270

Web Wheeler
Location
SaSa Sandy
Mine was a 2 valve.
Just reacquainted myself with that noise from my pal youtube. My knock was much slower than that

Might just have to pull valve cover off that side as well see if everything looks okay
 

thenag

Registered User
Location
Kearns
Not totally similar but I had a random misfire on a 3v v10 that no one could find.

It turns out that when I replaced the timing set an electrical connector that I had un-done on the driver side wheel well had the gasket in the connector slide out and prevent the connector from seating all the way. (wow I have never told this story in 2 sentences, it was about a year of crap figuring this out, new injectors, fuel pump...)

The clips on those coil connectors are real crappy, make sure the connector on that coil is seating and clicking in properly.

good luck good luck good luck

Nathan
 

TRD270

Web Wheeler
Location
SaSa Sandy
Not totally similar but I had a random misfire on a 3v v10 that no one could find.

It turns out that when I replaced the timing set an electrical connector that I had un-done on the driver side wheel well had the gasket in the connector slide out and prevent the connector from seating all the way. (wow I have never told this story in 2 sentences, it was about a year of crap figuring this out, new injectors, fuel pump...)

The clips on those coil connectors are real crappy, make sure the connector on that coil is seating and clicking in properly.

good luck good luck good luck

Nathan

Going to run through my plan, and if it doesn't fix it I'm going to have to tap out and take it to someone with more OBD2 computing power than my scan gauge and have them look at what is going on. The connector seems to clip into it fine. I picked up some electrical connector cleaner and going to spray out the harness tomorrow when I do the leak down test.

Thanks for the info
 

TRD270

Web Wheeler
Location
SaSa Sandy
Well tried to do the leak down test today, but after an hour of trying to get the hose to thread into the spark plug hole I had to tap out to go to work. That and I was about to set it on fire. Tested the coil it was fine. Cleaned up the connectors, and swapped coils. TBC later this week when I have time again.
 

4x4_Welder

Active Member
Location
Twin Falls, ID
I believe you need a long 14mm adapter, the threads are way down in there. I had to get a whole set to get the adapter I needed on short notice, but for the record the Mityvac digital gauge is awesome. It was more than my wife wanted me to spend at the time, but has paid for itself being able to recall compression numbers for people.
 

TRD270

Web Wheeler
Location
SaSa Sandy
I believe you need a long 14mm adapter, the threads are way down in there. I had to get a whole set to get the adapter I needed on short notice, but for the record the Mityvac digital gauge is awesome. It was more than my wife wanted me to spend at the time, but has paid for itself being able to recall compression numbers for people.

The compression tester hose went on with no trouble. This hose was a few inches longer and a real pain to try and keep straight. I'm going to borrow the compression tester again and see if I can use that hose to complete the leak down.
 

TRD270

Web Wheeler
Location
SaSa Sandy
So I was finally able to get the leak down test taken care of. More good but frustrating news. The cylinder has about 5% loss which my understanding is pretty normal. I put the fuel system cleaner in this last tank and its almost empty. So far the light hasn't come back on, but I haven't driven it in the conditions it normally comes on.

If I get a day off this week, I'm going to do the top end cleaner, oil system cleaner and get an oil change done.

Go from there
 

bamacpl

Well-Known Member
Location
Roy, Utah
I had this problem with mine & it ended up being a cracked intake manifold & leaking water into the plug wells thus eventually ruining the COP. This was a common problem on 97-03 5.4's & there is a new & improved design that doesn't crack. After i changed mine i haven't had a problem since
 

4x4_Welder

Active Member
Location
Twin Falls, ID
Ford take a huge number of misfires to throw a check engine light. Does Torque give you access to Mode 6 data? That'll give you the raw misfire counts before the check engine light comes on.
I use Car Gauge Pro myself, if you have one of the good ELM327 Bluetooth dongles then it's well worth the $8 for the program. The UI isn't overly user friendly, but once you get over the learning curve there is an amazing amount of info available. It does Ford specific, you can do nearly all the shop scanner tests, but you need to be in generic to do the Mode 6 scan.
 
Reactions: DAA

TRD270

Web Wheeler
Location
SaSa Sandy
I had this problem with mine & it ended up being a cracked intake manifold & leaking water into the plug wells thus eventually ruining the COP. This was a common problem on 97-03 5.4's & there is a new & improved design that doesn't crack. After i changed mine i haven't had a problem since
This is what Kevin told me to check, as he mentioned every hole is bone dry. All the "old" spark plugs look normal.


Ford take a huge number of misfires to throw a check engine light. Does Torque give you access to Mode 6 data? That'll give you the raw misfire counts before the check engine light comes on.
I use Car Gauge Pro myself, if you have one of the good ELM327 Bluetooth dongles then it's well worth the $8 for the program. The UI isn't overly user friendly, but once you get over the learning curve there is an amazing amount of info available. It does Ford specific, you can do nearly all the shop scanner tests, but you need to be in generic to do the Mode 6 scan.
I have nothing more than a scan gauge II, so maybe I should invest in an app and see if I can see how many are actually happening and when they are happening. Like I said before I can drive it around town and not get a CEL, I've driven pretty much this whole tank around town and it hasn't come on. It only comes on when i'm on the freeway at high speed and low rpm.
 
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