I have an 06 with 5.4 with 72k on it. A few months ago it started lugging at driving speeds in overdrive, at first I would just shut OD off and it seemed better. It has since gotten worse and does it in or out of OD, I thought maybe the converter was locking up, but I brought it to a local shop and they seem to think it's the plugs. Also, it gets worse as it warms up. Doesn't seem to be skipping at idle or if you rev it, just when you're cruising down the road driving normally. It's not showing a check engine light and never has. Just wondering if anyone here has had similar issue? Thanks for any info.

 

Can you describe the lugging with a little more detail for our/your benefit, it will help immensely for us to help you.

 

any time I have experienced a 5.4 that is "lugging", it had a bad COP... IF there is no code to narrow it down, you might can change all of them or one at a time until it goes away.

 

Not to sound stupid, but what is "cop"?

 

Coil on plug.

 

Moisture in the plughole can cause a misfire under load but still have just enough spark to idol normally.

 

looks like this... one on each spark plug

http://www.ebay.com/itm/New-Ignition-Coil-8-Pack-for-Ford-Lincoln-Mercury-V8-V10-4-6L-5-4L-DG508-C1454-/251453402463?fits=Year%3A2002%7CModel%3AF-150&hash=item3a8bca6d5f&vxp=mtr

 

A scanner can find which cylinder is doing it. Not a code scanner.

 

sounds like you are getting close to the plug replacement range, and you are describing the beginning stages. I would replace the plugs and see how it acts before you change COPs. Yes the COP is easier to replace, but remember the plugs are 100,000 ish mile plugs. My 06 did this at high speeds, more noticeable when let of the gas and then press on the gas again. changed plugs and went away

 

Any special preparation for changing plugs? I see a lot of different methods on YouTube, some spray carb clean or pb blaster down the plug holes, some use a 3/8 impact, some do it while the engine is hot, some say to do it while the engine is cold? Also, should I just do the coils while I'm at it? Recommendations on plugs, ngk champion or should I jus use motorcraft? Thanks for any info.

 

I used an impact worked for most of them, my engine was just warm. 3 broke. I didn't replace the coils due to money, and I went oem plugs, just me I have had to many things go wrong with aftermarket parts. I did spray anything in the holes. Make sure you clean really good, vacuum out the holes before during after.