I just went out to change my plugs in my 2000 F150 5.4 (engine code "L") and I pulled the first plug out and noticed that it had about four threads on it. I looked at the new Motorcraft platinum plug that I got fromt he dealer and they have aqbout 10 threads! Can I use these fully threaded plugs on my engine?
Thanks a lot in advance.
I dont want to put them in until I get some opinions!


Brian

 

Just talked to the parts counter guy at the dealership...He said that Ford replaced the short thread plugs witht he full threaded plugs. He told me that they will seat the same in the head no matter what and there is no difference. Lets hope he is right!


Brian

 

Just make sure that the distance from the seat face to the end of the plug is the same on the new plugs as it is on the old ones. If it is, no problem. If it isn't, and the new plug is longer, you will risk possible major engine damage.
Measure them to be sure.

 

I think you may have gotten plugs for P.I. heads. As Reloader said, tread carefully...or get a second opinion from another parts house.

 

I did check the length of the plugs to one another and they were EXACTLY the same. Only difference was that the new plugs had many more threads. I did call another Ford dealer who told me that Ford changed the plugs because they were essentially the same (besides the thread count) do eliminate part numbers to save money. Just for your reference, my old plugs with the short threads were Mororcraft platinum part #AWSF 22E and my new plugs are Motorcraft platinum part# AGSF 22WM.

Brian

 

This weekend I also changed my plugs on my 99 4.6. I noticed the same thing, however, I convinced myself that it was ok to use the new plugs. I did and they are great.... although I do think I winced a bit when I cranked it for the first time. I dont recall the plug numbers, but I used motocraft.... both plugs had some letters, (many were different) and the numbers 32, which stick in my mind because they were the same on the new plugs. Anyway, if you hold the new plug to the old you can see the shoulder where the plug seats and the distance between the shoulder and where the threads start is exactly the same. Those "extra" threads don't do anything.... they are between the seating shoulder and the bottom 3 or 4 threads that do screw in. Convince yourself they are ok before you use them in your truck.... but they were fine in my truck. By the way the old plugs had 100k and ran poorly for the last 15k. When I checked the gap the new plug gap was about 56 thousanths..... the gap on the old plugs was about 90 thousanths.... by the way, a great tip I got from this site was to use 2 cement blocks to stand on (one per foot).... it really helps your back.

 

I am officially done changing the plugs! They did work fine (thank god). It wasn't really THAT BAD of a job besides getting the 7mm bolt off that hold the coil onto the second plug from the back on the drivers side. Wow, that took some time because I didn't remove the fuel rail. I actually had to go to Sears and buy a 7mm longer 7mm wrench to make it an easier reach to get it off. This website is wonderful!!!!!


Brian

 

The extra treads on the spark plugs are probably due to an improved cylinder head for the 5.4L. Seems like there is a problem with the number of treads in many original 5.4L cylinder heads. I have noticed that there are only about three treads on the original heads. The new design has more like nine treads. The problem with the original head was that spark plugs were being blown out and damaging the treads on the cylinder head. Ford recommends replacing the cylinder heads when this happens (ouch). Other shops use a special helicoil type insert to restore the treads. It's just a thought, but maybe that is why the spark plugs have more treads now.