Recently just changed all the spark plugs and coils with motorcraft as recommended. Just bought the truck. After I changed all of them I'm experiencing this loud popping sound which sounds like it's coming from the top of the engine. I checked to make sure all hoses and connectors were put back right. I took a video of the sound, it occurs at 20 seconds. The sund goes away if I rev the engine over 1.5k. Also did a bunch of research on this engine and found it is very specific when it comes to parts and oil, I doubt the right oil is in there and I know the previous owner didn't use a motorcraft oil filter, so that's on my list of things to do as well. Just want to know what kind of issue I'm dealing with with this noise. Any ideas/help would be trmendously appreciated.

https://www.youtube.com/watch?v=tyOk...ature=youtu.be

 

Sounds like it is popping back, like maybe a burned intake valve. Don't believe me. I'm just wild guessing here.

 

Can you determine if the noise is coming from one cyl area such as the valve train of cyl # 5...pick a number. It could be a lash adjuster or finger follower failing and it is bouncing but you need to locate the exact location. If it is behind the front cover could be the timing chain tensioner allowing the timing chain to snap from slack. Has anyone ever had the intake manifold off? Also to be clear this noise was not present until after you replaced the plugs and coils? If you removed the 7mm COP retaining bolts did you happen to lose one? You may want to remove the serpentine belt and listen if the noise goes away. A belt tensioner or idler pulle
y can make that noise as well if a bearing is going out. I doubt this is a a oil issue. It sounds like a metal component the question is why did it just start after you changed the plugs and coils if thats my understanding. Are you also sure you got all the sparkplugs torqued properly?

 

It's kind of hard to determine the exact location, but the sound is coming from the intake manifold. When I put my hand on it I can feel a vibration whenever the popping sound occurs. Almost like an intake backfire is taking place. I've been out of town so haven't worked on it anymore. I haven't taken the intake manifold off yet. But yea it started whenever I changed coil packs and plugs, also I noticed oil where the plugs are telling me I need to replace the valve cover gaskets but I doubt that has anything to do with it. All the 7mm bolts are there and tight and all the plugs are torqued properly.

Only other thing I can think to try to eliminate some possibilities is to disconnect a plug and fuel injector on each cylinder and do a process of elimiation?

Other than that it doesn't seem to have lost any power, just has a rough idle - the whole truck vibrates.

Any more help greatly appreciated!!

 

Did you ever solve this issue, I just had the exact same problem. Changed coils and plugs, pcv. And it started doing the exact same thing. I've even replaced all plugs coils and pcv back to the old
Ones. It still has the exact same symptoms. There's no codes either. Mines an 07 expedition

 

It ended up being a broken rocker arm on passenger side. I was able to replace it myself with Haines manual and this site. Also replaced lifters, rocker arms, springs etc as a precaution, been running great since! Had a couple friends say I could have just replaced the broken rocker and waited to see if it would break again but my truck has 140k on it so I just redid everything.

I was able to pinpoint the issue to the bad cylinder by removing electrical connectors to each fuel injector, you'll be able to notice a loud of power of the cylinder is good as you go through, if there's no change in power that's a bad cylinder. Let me know if this helps!!