Just got back from an awesome vacation to NYC/DC with my fiance (pre-honeymoon I guess). Started the P71 up to drive from the airport home and guess what decided to break, again? ANOTHER STUPID PLUG!!!!
I loathe that stupid freaking mod motor. It is definitely time for a new car, I am done with this one's engine.
Wait... how do you break a plug? Did you not never-seize it or something?
The Ford mod motors used like 2 threads in the alloy head to hold the plugs in place. They tend to pop out violently, taking all the threads with them.
We see it all the time behind the parts counter. They make a kit to "fix" it.
Well that sucks!
Well, since P71 is one of the GRM trinity, I think this deserves some special research. If P71 is the answer, but the engines are not part of the equation, what is the solution? I know there's a GRM P71 with a 5.4 Triton conversion...
David
well.. maybe it is time to fix the rest of the plugs before they break?
Time for DOHC 4.6?? Or do they suffer the same fate as the SOHC mod motors?
Did later version fix the problem? (Like the 3 valve 5.4 in my truck?)
time for a V10 swap.
Strike_Zero wrote: Time for DOHC 4.6?? Or do they suffer the same fate as the SOHC mod motors?
My DOHC 4.6 never had anything resembling this problem.
And if we're gonna talk swaps, the new 4v 5.0 is now offered as a crate motor for only $7k, though my recommendation would be the 6.2L V8 from the raptor, or an LSx.
Did later version fix the problem? (Like the 3 valve 5.4 in my truck?)
Ho ho! Ho hohoho! Hohohohohoho!!
Think OPPOSITE!! 
They took the problem with the old ones and made it worse, imo. Those ones the extended tip of the spark plug gets stuck in the head and breaks off the plug when you thread the plug out. Its worse than the thread pulling because the fix is harder and doesnt ALWAYS work, and when it doesnt work you have to pull the head.
It is definitely time for a new car, I am done with this one's engine.
All the love you spew for the p71, gone like that?
This is a Ford engineering problem thanks to a bean counter. They decided to save .2 seconds per head by only drilling 3 threads into the plug holes. ALL 2V SOHC heads face this issue (96-04 Mustang GT, 98-10 Crown Vic/Grand Marq/Town Car, F150, E150, etc). The DOHC heads did not have this issue, nor the 3V SOHC heads on the 05-10 Mustang. However, the 5.4 2V had the exact same heads (and thus, the exact same problem) and the newer 3V one have their own unique plug problem.
I've never been a fan of this engine in SOHC form, and have posted that displeasure numerous times. At $300+ per plug hole (and there's 8 of them), it's really not cost-effective to "pre-fix" the stupid things.
I dunno what I'm going to do. My car is coming up on 150K miles (I've put nearly 27K on it) and it's going to need a lot of maintenance soon (trans service, ABS fixed, brake calipers, front shocks, etc) and added to the plug problem I think it's time to let it go. It's stranded 40 miles away right now.
Shoulda stayed with the 150 shot. 250 was a little too much! 
In reply to P71:
Are you going to change your screen name?
Fix it right once put inserts in all the plug holes and be done with it. They changed the heads after a year or two to full thread heads, at least they did on the V10
DWNSHFT wrote: Well, since P71 is one of the GRM trinity, I think this deserves some special research. If P71 is the answer, but the engines are not part of the equation, what is the solution? I know there's a GRM P71 with a 5.4 Triton conversion... David
I say it's out, That's too big of a problem to be the answer any more.The Volvo or Jeep Cherokee is in, in it's place.
$300 bucks a hole seems high. I'm pretty sure you can buy the timesert kit that every shop in the universe has to own now for less than that.
Ok, I was a bit low.
http://www.etoolcart.com/time-sert-ford-triton-spark-plug-repair-5553.aspx
What about dropping that DOHC job out of the Lincoln you scored into the P71? Or are you just done with the thing all over?
It's stranded 40 miles away right now.
Why is it stranded? Unplug that injector and drive home..
DWNSHFT wrote: Well, since P71 is one of the GRM trinity, I think this deserves some special research. If P71 is the answer, but the engines are not part of the equation, what is the solution? I know there's a GRM P71 with a 5.4 Triton conversion... David
More proof that the Trinity is actually Miata, E30, Astro.
Crown Vic loving heathens!
a guy I worked with drove from Minneapolis to Iowa to purchase a used John Deere tractor and he blew a few sparkplugs and had to pay an unfamiliar Ford dealership fix his truck. I thought that was odd.
You would think that spark plug threads would be designed right after 90 years or so....
More proof that the Trinity is actually Miata, E30, Astro.
Hmm.. i only like early astros.. and i only like late p71s.. but generally i tend to like the Astro more so i agree!
You would think that spark plug threads would be designed right after 90 years or so....
Well at least on the trucks they designed the windows to automatically fall down so you can hear the spark plug blowing out more clearly..
Vigo wrote:It's stranded 40 miles away right now.Why is it stranded? Unplug that injector and drive home..
been there.. done that. I was running carbs, so could not unplug an injector.
It was a VERY loud and powerfree trip home
Osterkraut wrote: More proof that the Trinity is actually Miata, E30, Volvo turbo.
Fixed that for ya! 
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