I have read that the older 5.4s had just a few threads of engagement, which gave the motor the reputation of "spitting" spark plugs. Also, the plugs would sometimes seize in the block and be a real PITA to remove.

Did the 4.6 suffer from these same issues? I'm looking at 2003 truck with a 4.6 and want to know what I might be facing.

Thanks!

 

Every 2V modular can spit a plug, they all had the 4 thread heads until '03 but some have still had a 8 thread head spit a plug. The 5.4L and 4.6L used the same head. The plugs "sticking" in the heads are a 3V issue until around '09. I've never once heard or read of someone with a 2V getting a plug stuck but the internet myth seems to be spreading lately about it. I wouldn't be too worried about the spitting issue especially with an '03.

 

Thanks! Just what I was hoping to hear. I dodged a bullet with my 09 250, but it made me cautious about earlier models!

 

I am probably picking up an 03 F-250 with a 5.4 in it today. At what point did they change the thread count in the head for the spark plugs? this truck was manufactured in November of 02 yet is an 03 model. Did the 8 thread plug holes not start until a manufacture date of after 03? either way, from what I've been told, is that if the proper torque specs are used I shouldn't have a problem with either one. I have never had a 5.4, so I'm at the mercy of the experts until I learn this motor a little more.

The engine currently has 112k on it and runs like a Swiss time piece, and is as quiet as a church mouse. Obviously has been well taken care of. (by the sounds of things anyway)

 

Digger you're right about plug issues across the board on Ford's modular motors. While it does happen its certainly NOT an epidemic or guaranteed to happen to every modular motor regardless its CID.

Here's something I believe capsulizes plugs---pay closest attention to posts #2 & 7: https://www.ford-trucks.com/forums/1...ed-torque.html I've used my own version of those recommendations and have yet to experience any issues at all. With both an '00 and '03 5.4 that have the 4 threads-per-hole heads it works without any problems.

HTH

 

I would assume that the plug spitting problem is more likely to happen to an engine that is constantly under high demand. (always under a load, or having the p*ss run out of it) Am I correct in my thoughts? I pull a 16x8 enclosed trailer from time to time, but it's never got more than 1000lbs in it. other times it's just general driving conditions.

 

Use isn't really a factor with this problem--it seems to stem more from incorrect installing or removing of plugs on the earlier heads. Those are typically called "3 (or 4) threads per hole".

There have been instances of new engines will less than 5K miles experiencing this which suggests even the factory could and did muck it up. It did seem completely random to more than a few earlier on but as experience built the caused could be traced to the installing/removing procedure.

 

I just did the plugs on my 2001 4.6l with 175k miles, I've never spit a plug nor have the plugs ever seized but they do go deep into the block so make sure your socket has the plug boot inside it!

I've also got a question for anyone who could answer..

My truck is throwing P0401 (insufficient exhaust gas recirc) code. The EGR is a couple weeks old, so just about brand new. Recently i did the intake... could the loss of vacuum in the intake throw this code? any fixes?

 

Go ahead and start a new thread on that topic. Either here in the Modular V8 forum, or in the one for your vehicle (F150?)

Put your problem in the title ("P0401 - Where should I look?" or "Help fixing P0401" - you get the idea)

That way folks will see it and address it.

Good luck! And thanks for the tip on the deep-in-the-block

 

Thank you! Im new on here, so just a little clueless lol

 

We have all been there - no problem.