Home Forums Hunting & Shooting Hunter's Campfire Ford 4.6 engine miss?

I've got a 4.6l 2 valve that has an intermittent stumble while under a slight load. Does not trigger check engine light. 5 of the coils are newer 4-5 yrs. Other are motorcraft age unknown. Will I have to wait til it gets bad enough to set a code, or is there another way to find out issue. I have not changed plugs yet, but probably will. Not crazy about changing them since they tend to blow out on these aluminum heads. Any suggestions are appreciated.

Probably the coils again.

I'm gonna go start it in a few minutes since it's nearly dark. Maybe I'll find one leaking fire.

If you know someone with a good scan tool it will have a misfire counter and can tell which cylinder is misfiring, even though the light is not coming on.

I would do two things:

1. Replace the plugs if they are anywhere near used up, or maybe even just halfway used up...and buy the highest quality long-life plug the factory recommends

2. Replace all 8 coils all at once---don't screw around with it. Be sure and buy Mototrcraft parts from a Ford dealer or the warranty will be meaningless (I found that out putting coils on my 5.4 L last summer, which pissed me off mightily but could do nothing about it).

I have actron scan tool, but think I need a newer model to do what your talking about.

Generally all you will get is a P0300 random misfire code.

Start with finding a scan tool that will monitor misfire cycles. If plugs are old no time like the present to change them. The head issue isn’t reason to no fear them. Heli coil kits for them make the fix a beeeze.

Damn even their pocket readers access misfires. I/M monitor section. Actron has your user manual online. Mine is 15 years old.

I play with 4.6 a lot.

Could have a bad plug under a good coil.


But most likely it’s a coil. I’ve got a guy that has a scanner he hand figure out which one. Make sure to always replace the spark plug when that bad coil is found.

I have four vehicles with 4.6 and one with the v-10

I wont even drive these sombitches thru a mud puddle any more. I have a low water crossing on one county road, i’ve lost coils on 2 separate occasions slinging spray up onto the engine.

To add

I never get a CEL with a bad coil.

Unless I blow the plug through the top of it. BTDT that a couple times too.

I'd like to have a little chat with the Ford engineers about the V-10.

MOFO's

Yeah it sucks

Took me an entire weekend with a step ladder to do 10 plugs and 10 coils.

I had to fix up a jerry-rigged shop vac attachment out of heater hose to suck out acorns and hickory nuts gnawings so they didnt fall into the plug hole.


Yeah and those back plugs under the firewall....

Make sure you put anti seize on the plug threads and delectric grease on the plug nipple. Nothing makes it more fun in the future when you pull the coil and boot stays on the plugs

Mfkers in a 8” deep well.

Needle nose locking vice grips

V-10’s and all the other Tritons have lined my pockets well through the years

I despise these coil on plug aluminum engines. I long for the single coil distributor days.

Along with the never sieze and grease--cold engine and patience

I’ve got me a shop now that will do spark plug Timesert rethreads for $200

Research the fuel pump driver module. It's a common problem-item that can cause all kinds of weird issues.

Also, check your spark plug galleys for coolant, could be a leaking intake gasket.

Are you leaking any fluids on top of the engine? Valve gasket/thermostat housing?