Hello...new to the site here. I have a 2004 F150 Lariat 4x4 crew cab...Over 100K miles on it...got the shuddering issue I am sure many are aware of, between 40-50 mph. I have the original plugs in it still. A few questions..

I think one of my Coil on Plugs may be bad. I was planning on replacing them and changing the plugs (Motorcraft or other?) Maybe it was a bad thing, but I tried that "stop tranny shudder" in the tranny but no improvement. On to plugs and COPs next


1) Original plugs at over 100K, should I do myself? Stay Motorcraft or other?
2) Are the new replacement plugs one piece now?
3) Motorcraft or other COP? Others like Accel are cheaper.. Thoughts?

other than change oil and filter at same time, anything else??

Thanks...

 

If you turn over drive off at the 45-50 mph you can drive through the shutter until you get things changed out.

1)If you are mechanically inclined change the plugs yourself. Get the Lisle tool in case any break. (I had 4 break and the tool helped get them out w/o a problem)
2)Don't think they change the plugs to 1 piece but I can be wrong.
3) I put Accel COP's on. I think I went by reviews of them on here.

If it wasn't for this site and the threads about the plugs I wouldn't have done them myself.

 

Thanks. I was just looking up how to use the Lisle tool. Have to track down part numbers for coils, plugs etc. Then purchase tools

 

When going for parts, engine info needed .
Over 100k on orig plugs is not recommended, But New plugs are sp515 's are probably what your engine calls for, they are welded now, not crimped so not much trouble with shearing off .
Wholesale changing of oem coils not needed , oem coil contacts should cleaned good . All new boots should be installed heat/oil damages them ,they keep that 30000 volts from jumping to head .
Plugs need to be torqued in 25 to 28 foot pounds-- not by feel . Cop bolts have been shearing off due to corrosion put a little anti sieze on them .
Blow out the spark holes real good before you start . Use dielectric grease on ends of new boots not on electric contacts it is an insulator .
Read ford TSB on changing plugs , I like to soak orig plugs with carb cleaner for hours then loosen plug 1/8 turn then after a while wiggling same amount to work past threads to dissolve carbon around tip .
Some sp515's have been failing out of the box be aware .
Most of us are pulling PCM and bracket to get access to 3 and 4 ,get you some cushions to put on radiator to lay on . A bench in front of bumper will help , be careful around VCTs on engine some guys have broken them off putting pressure on them .
I use champion 7989 's ,they are expensive but I have no trouble with them.

 

good info redfishtd.

New boots and springs with a cleaning of the COP contacts should be done first before replacing the entire COP.
If you do need to replace, Motorcraft is highly recommended.
The made in China coils have a very high failure rate (many times out of the box). I have read of some people ordering 2 sets, and out of those 16 getting 8 that work, and then a few spares that may last a few years.
Others have bought 8 and have no issues.

I have not heard of any issues with the sp515 (aside from ones with cracked porcelain or other manufacture defects or damage, which is why I always buy my plugs in store so I can inspect them, or order online early enough so I can inspect and replace any that may have been damaged in shipping).

I got all 8 out intact using the TSB instructions @ 156,000 miles on my brother in laws '04 5.4. Was worried with #4 and #8, thought they broke, but luckily they did not.
I know some say use an impact to get them out, but I just was not comfortable doing that.
Both ways have their success and failure stories. Either way, have the Lisle extractor tool ready just in case (I ordered one from Amazon and was able to return it since I did not use it, I know sometimes they show up for sale here and on local craigslist for cheaper).

 

COPs are most likely not the root cause of your misfires. A careful 'meticulously clean plug job' (No greasy finger prints on porcelain), good solid electrical contacts (replace any broken COP connectors), a dab of dielectric grease on the 'NEW' boots, with a good set of new plugs is most likely the answer.


Whatever you decide to do, you might consider this:

https://www.f150forum.com/f4/5-4l-3v...6/#post3932639

 

New boots and springs and plugs..then decide. Not sure how much that costs, I mena the springs and boots. How to replace the springs? Also, Dielectric on boots only vs no dielectric on contacts, yes?

 

Boot and coil part numbers? Weird thing, seems like I always come across different part numbers..

 

also, on Ford Parts, they list SP 507, not SP515 as the plug...

 

Sp 507's single platinum were 2 piece crimped and were terrible about breaking off due to carbon seizing tip , causing very expensive head jobs . Sp 515's were designed to stop that . There is some controversy whether 515's are double platinum . That is both the electrode and ground . Some say it doesn't matter . The box doesn't say so that says it's not .
Lately there are some reports of bad sp515's out of the box .
I use champion 7989's double platinum that are welded not crimped, after 3 sets no failures . The downside is they are expensive .
Sp 515 box calls for 23 to 27 foot pounds and 9/16 socket . 7989 's use 5/8 socket .
In either case replace boots with new , use dielectric grease only on rubber boot ends not electric terminals --it is an insulator . . Keep porcelain clean and torque plugs 25 to 28 foot pounds . Use rubber spark plug sockets and start by fingers .
Of course blow those holes out before you start and clean holes out with carb cleaner.