I have a 98 Expedition and it has blown 3 plugs. It has very high miles and am looking to get a little more wear out of it. My question is does the blowing plugs restricted to certain years in the 5.4 motors? I'm thinking of some aftermarket exhaut and programmer for the Expedition that I could use on a '02-'03 F150 when the Expedition gives out, but was wondering if the plug problem happens in those years also.

 

Never mind, I found the information that ot os common up tp '05. Thanks anyway.

 

I have not done any research, but I had the understanding that it was fixed in 2002 maybe. They added threads to the plug holes. PM Jbrew, if he does not chime in. He will know for sure.

 

No, the blow outs are in the old style trucks it was fixed before the 04 3 valve engines. The old heads were fixed in 02 I believe. The new engines have a different problem with poorly designed plugs that come apart when you try to remove them.

 

No...'02 still had 4 threads and blow out problems. It's also not confined to 5.4s. 4.6s and V-10s have blow out problems. The V-10 more so than the 4.6 though I belive.

 

97-02 The 2v engines in 03 (and up) have more threads..♠

 

Bingo- Jethat finally got it right. Should have been in late '02 for the '03 MY but I have read of some early '03's even having the short threads. I think that was probably because Ford has for most of their history had a habit of using next MY parts if they run out early, or using last MY parts if they still have parts left over. The only place they can't do that is if there are smog or safety parts that changed between the years. I have seen the "forward" or "backwards" parts situation many times on Ford's. My brother is a Model-A enthusiast and expert and he said they did it clear back then.

 

Sam- see my post. '03-up, deep threads. Galaxy is right, it does happen in all the modular engines of those years. Maybe more in some displacement than others, but they all share the same design.

 

If you use Motorcraft plugs and torque them dry (NO antiseize) to 28 ft/lb, you won't have any blowout issues.

 

The plugs didn't get more threads in them until LATE 03!
My 03 came with the 4 thread heads.

Phil