Hey I'm really needing some help with finding out what's wrong with my truck. It started off with a plug blowing out of the head. I took it to a shop and got it rethreaded. Then about a week after I got it back it started to misfire it was just a small misfire. Then by the time I got home it got worse. So I pulled the codes and two misfire codes pulled up. I took the plug out of the cylinder the threads were repaired and the whole tip was gone. So I decided to just replace all plugs and coils with new ones. That didn't change a thing. Then I bought injector cleaner and took the edge valve off to try to clean it then put it back on and let it run and the miss is still there if anybody has a clue to what is going on with the truck please let me know I've already been two weeks without driving it. Thanks. Oh and I forgot to mention it has the 4.6l

 

Hey I'm really needing some help with finding out what's wrong with my truck. It started off with a plug blowing out of the head. I took it to a shop and got it rethreaded. Then about a week after I got it back it started to misfire it was just a small misfire. Then by the time I got home it got worse. So I pulled the codes and two misfire codes pulled up. I took the plug out of the cylinder the threads were repaired and the whole tip was gone. So I decided to just replace all plugs and coils with new ones. That didn't change a thing. Then I bought injector cleaner and took the edge valve off to try to clean it then put it back on and let it run and the miss is still there if anybody has a clue to what is going on with the truck please let me know I've already been two weeks without driving it. Thanks. Oh and I forgot to mention it has the 4.6

 

I suggest you check the compression in the repaired cylinder. It sounds like they let some debri get into the cylinder to cause the tip of the plug to disappear. Just wild guessing here.

 

This is the plug

 

Might want to check compression on the repaired cylinder to make sure something didn't get in there and mess up a valve.

 

That looks like it was burned off by too much heat in the cylinder or too hot of a plug.

What procedure did the "shop" use to reinstall the plug. If they used a helicoil, it won't last. Timesert

 

Sounds like a bogus blown repair...

 

what coils are you running? Did the blown out plug take out a coil and get replaced with an inferior aftermarket coil?


Per our website rules, I have merged your two threads, so we can all be on the same page. Much less confusion this way.

 

Yeah I'm going to do a compression test next. When I do one on the truck can I just test that cylinder or do I need to remove all and check them all? And the shop said a helicoil won't hold so they used something else for an insert I can't remember what it was. And are these trucks funny about different coils? And thanks for the replies also

 

The only inserts that last are Timesert and Lock N Stitch.

They can be fussy about coils - anything other than Motorcraft/Visteon can be a crapshoot. The only cheapies I'd take a chance on are Araparts.

You can test just one cylinder, but you need something to compare it to. I'd do them all if you are going to the trouble of doing it at all.

 

You may have an exhaust valve finger follower that has popped off location. Unlikely that a compression test will show that. A compression test will tell you if a intake follower is off as you will not pull air into the cyl to compress because the valve will remain closed so you will show zero compression but not with a exhaust finger follower off. With the exhaust unable to escape you will increase cyl combustion temps and can burn a plug off. Other things can cause the same condition of course. I would remove the cam cover and take a look for a finger follower misplaced. Just another possibility.

 

The compression on that cylinder is showing 0 and the cylinder beside it is showing 120. I took the cover off and everything is in place. Everything is moving like its suppose to. I don't know if maybe the insert they put could not let the gauge get a reading from not sealing?

 

Sounds more like the cylinder has internal damage. Go rent a borescope.

 

Yeah I'm going to stick a camera down there tomorrow and see what it looks like inside