2007 Ford Expedition Engine popping loud, please help?

[chris2888]

I have a 2007 Ford Expedition Limited EL 4x4 with the 5.4 Engine. It has 182k miles. For the past 3 months it has started popping on acceleration over 50mph. At first I could kick down the OD button and it would stop, now its doing it most all the time once I get up to 50mph or over. Especially under acceleration or pull.

If I let off the gas it stops in about a second. It sounds like sparking n popping almost like popcorn is going off in the engine. Like a crackle. From research it looks like Spark Knock, or Detonation. Either of these are concerning as I do not want to ruin the engine.

I personally replaced all the Spark Plugs n Coils about 1.5- 2 years ago, but already it has burnt out the #2 and # 5 spark plugs the past 2 weeks. I just tried cleaning the MAF really well, and took the vehicle out today but, same issue. I run Seafoam it the gas tank once every other month.

Here are my thoughts, what do you think?

• Should I try to get the Carbon cleaned and run some SeaFoam direct instead of the Gas tank?
• Could it be that the spark plugs are worn out again( would this cause such a bad crackle? Had lots of Fords with worn out spark plugs but never had this problem. I know 5.4 is notorious for spark plug replacement)
• Should I buy another MAF sensor thinking maybe this one is bad? Its got 182k on it?

I have listened under the hood and put my hand to see if I could hear a vacuum leak, or anywhere air could be blowing out and nothing.
The engine is as smooth and quiet as it was at 50k miles when idling. Once it gets up to speed it is loud crackle n pop.

Any thoughts from anyone who has had this problem? What could it be? What was the fix?

Thanks for the help.

 

[JExpedition07]

Where did you get the coils from are they Motorcraft or were they Chinese after markets? What are the condition of your spark plug boots? Reminds me of the old 2 valves they would pop when they were ready to throw a plug out but the 3 valves don't have these issues. Sounds like backfiring. Carbon tracking, ignition wire problems, Retarded timing, rich mixture etc can cause your situation...

 

[chris2888]

I purchased the plugs n coils from Ford. They are Motorcraft parts. I figured since these plugs were such a headache to replace, wanted to get the stock ones from Ford.

The two I just replaced the boots looked great, but the spark plugs were pretty worn for sure. I have never had this issue on multiple Fords/5.4 engines I have had. So thinking I am missing something. Didn't know if the carbon buildup would cause it.

Thought it might be EGR, but the engine runs perfectly and no miss at all when idling. I cant smell it running rich, but that doesn't mean it isnt. The catalytic converters could be getting stopped up, but didnt think that would cause this problem.

Could the timing be messed up? Anything with the throttle body issues?

 

[stamp11127]

Post a decent video without wind noise to narrow it down.

 

[chris2888]

Sounds good let me see if I can get one and will post it later. Thank you for the help.

 

[1955moose]

Along with stamp, I agree, run another audio. Popping is generally either a loose sparkplug, or a problem with a valve not opening/ closing proper. Run a computer codes diagnostic too please. If those 2 cylinders are wearing out plugs prematurely, rare these days, sound's like a overly rich/lean condition, without the proper spark/timing. I'm reaching here but I'm leaning towards a cam phaser that's retarding engine valve timing causing your popping. I know its tough but if you could run a full 8 cylinder compression test. Anytime you've got a camshaft, valve, or ignition that can't keep up with fuel delivery, and spark, it will pop, or backfire. On the opposite end too little fuel, or too much advance will cause severe detonation, or pinging under load, like pulling a grade, or in a higher gear. Your 2 worn spark plugs is a strange one though. I've seen them crack, foul, when overly rich or run lean, but never wear out! Post what you find.

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[1955moose]

I just was texting back and forth about your 2 worn plugs, he's a retired Ford mechanic, he said 2 bad cylinders! Are your 2 worn spark plugs side by side, like #1 and #2 cylinder?

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[chris2888]

I have been working on this for an hour, hope you guys can listen. I taped one earlier today and one tonight. It got worse once I drove it farther and later in the evening.

https://www.youtube.com/channel/UCZ2z3E6q5fJrj5XW4608jlA

 

[chris2888]

Hey Moose thanks for the help. I just posted a video of the sounds, but its hard to hear. The cylnders were #2 and #5. They were not next to one another on the firing order. Across the engine.

I might have to run a compression test as I have not done that. Its getting worse for sure and does it all the time on any grade or acceleration.

 

[JExpedition07]

How many miles are on the truck? I highly doubt you have loss of compression. I hear what you describe slightly in the video but it's very subtle.