I very recently bought a used F-150 Supercrew, 5.4l, and it had 98,000 and I rolled it over 100k last week and decided it was time to change the plugs on it. Well, the small bolt holding down the first COP on the passenger sided just spins, not too freely, but will not back itself out. What should I do now? I have tried prying up on the COP ever so slightly to get a thread to grip, but no luck. So, I removed the COP on the drivers side front cylinder and took out the plug. I found fairly new Bosch Platinum +4 plug. The plug does not look old at all, so a plug change is not necessary right now, but since I have it out of commission for the weekend I would like to get the problem w/ the stripped COP taken care of. Any ideas? Thanks in advance.

 

Faced with the same , I would put some PB Blaster or equiv. then use a tool that can get under the head to put upward pressure on the bolt and try again to get it to engage it's threads.
But be carefull not to bind it and break the bolt off.
I would venture to guess some lower part of the threads are loaded with alum and is causing the condition.
Once out, retap using alum lube and a bottoming tap for the next size SAE thread even though it is now metric.
You need to select a bolt size that still fits the COP hole and/or drill the COP oversize a small amount.
If you have a last resort, drill down along side the original bolt to provide more room. Try again to get it out.
Then drill the manifold oversize large enough so an adapting slug can be put in that reduces to the original bolt size again.
You may lose the COP's mounting hole in the process so locate a source before hand.
I usually do the easiest and progress to the more radical untll the problem is under control.

 

I now would be suspect of the last plug job and check all the COP bolts. The one in the front is the easiest to get to and it is stripped! Imagine what the ones in the back are.

In addition, a lot of people on this site have had horrible luck with the +4's

Your best bet to get that bolt out is to either pry up on the bolt head with a small slotted screwdriver while turning. Or break the head off pull the cop and then get at it a small set of channel locks.

Make sure you put the plugs back in properly so you don't shoot one.

Good luck.

 

My 98 has an aluminum intake, but didn't they switch to plastic in 99 or 2000? If your intake is plastic, then the threaded insert is spinning inside the intake bore. This appears to be a common problem with this type intake.

 

I had the same problem with 2000 F150 5.4 V8. I had the plastic intake and the cop just spun on the same passenger side first one. I pulled out the threads with pliers. I did this by snapping the cop off of the bolt and then yaking the bolt and threads straight out. I then JB welded the threads back in being careful not to get JB weld inside the threads. I let it dry a day or two and I was back in business after I got a new COP for that one.
Hope this helps!