Lately I have begun noticing a slapping noise from the passenger side upper engine (I dont think it's a knock, I hear it with any octane)
This sounds almost identical to rocker slap (or running out of oil) on a pushrod engine, but the 5.4 is an OHC, this is where I am getting confused.
The noise comes and goes, but is most apparant during warm up, and acceleration. Is the 5.4 prone to sticky or broken valve springs?
This truck is very well maintained, including oil changes at 3000/mi or 90 days without fail.

Am I missing a major 100K service item here? I dont know whether Ford recommends any valvetrain or head work at this mark.

Thanks for any heads up you may have.

this is a 97 4X4 5.4, 120K miles.

 

I can tell you exactly what your problem is. Your spark plugs are coming loose and will soon exit their proper location with a BANG, literally. I noticed the same thing on my wife's Expedition and passed it off as rocker knock. All I have owned until now have been push rod engines and any Ford OHV motor will exibit rocker knock when the oil needs to be changed. I changed the oil and it didn't go away. Oh well, I figured, it has 100k on it, maybe it's just getting worn. Lo-and-behold, 2-3 months later, after many 300 mile round trips to San Diego and a trip to Washington state, the #2 plug came out with a vengence. I am glad it happened close to home so my wife and two very young children were not stranded. The plug was chewed up, the coil was smacking the fuel rail, and it sounded like the exhaust manifold blew apart. I was able to get a new plug to catch 2 or 3 threads, put the coil back togeather and drove it home. I searched high and low for a solution and finally found one. I think I saw it here as a matter of fact. The company is called Time Cert and they have a specific kit for the Triton engines to bore out the original plug hole, tap it, and install an insert to permitly solve the problem. It runs about $130 for the kit, and each insert is about $8. It took me a good 12 hours to do all eight, and that was with a freind and air tools, but I didn't have to buy anything else, not a single gasket or drop of fluid. Go to www.timecert.com for more info, or e-mail me at ivan.snyder@navy.mil for my experience and what I had to move/remove/do to complete the job. For now, just check your plugs and re-torque them when ever you start to hear the tapping sound.

 

Thanks, I am pretty sure the plugs have never been changed so I'll do this ASAP.

 

I had changed my plugs over a year before this happened and I was positive that I got them good and tight. I have changed more plugs than I care to remember, so it isn't like I am new to this either. Anyways, when I took them all out to put the Timecerts in, at least 4 were loose enough that I almost didn't need the wrench, just the socket. I used Bosch Platinum as that is all the parts stores around here carried for this app. I am very pleased about the incerts and would highly recommend it to anyone. If you are around the San Diego CA or Yuma AZ area, I would do it for a small fee, and save you, or anyone, from buying the kit. I think I could do it in less than 10 hours now that I know what I am doing. Thanks.

 

I changed the plugs, but still the noise occurs. Could this be piston slap?