I have a 09 F150 STX with 136k miles on it. A year ago I had the dreaded loosening of the plug and it stripped the hole out. I fixed it with a tread repair kit I got from Napa. Well all was good until 2 days ago. I lost power and got the misfire code on the cylinder I repaired. Long story short, it's in the shop and they tell me that the head needs to be removed just to see if they can repair it. I guess my repair job was not too good! Anyways they say it will be $2200 just to remove the head and repair if its repairable. But there's no guarantee. The head could need replacing. I am waiting to hear back what a new head would cost. I am really hating ford now, I can't tell you. These guys are pretty straight shooters as I have dealt with them before. Just don't know what to do. The bottom end probalby has another 100k.

 

Find a shop that can try a "BigSert" or get the kit and do it yourself.

http://www.timesert.com/html/bigsert.html

I assume you have a 4.6 2 valve?

 

Yes I have the 4.6 2 valve. How do you get the old insert out?

I can see the plug down in the tube, but the spark plug socket just spins.

I am guessing the threads in the head stripped again? So can I just pull the plug out some how?

Also, can I do this job without removing the head?

One more thing. I drove it to the shop, about 4 miles. Is this advisable.

I would like to fix this as I feel the motor is pretty solid. But I don't want to put thousands into it.

 

I'm going to get a timesert kit. Nothing to lose. I put an insert in before, and it lasted more than 20k miles. The timesert looks better than all of the others. I just hope I can get the old insert out!

 

Timesert is the way to go. It locks in.

 

You will need a BigSert, not just a Timesert, if you have a different insert in there already.

 

There was one in there made by Stanley fasteners. Its out now. I will let them know that when I order.

 

It's very rare for spark plugs to blow out of a 2 valve 4.6 or 5.4 built in late 2003 or newer, that's when they changed the heads from 4 threads to 8 threads. You may not be installing plugs correctly, the factory torque spec is way too loose.

You should be using only Motorcraft plugs, *NO* antiseize, and torquing them to 28 ft/lb.

If worse comes to worse, the guys at blownoutsparkplug.com can probably help you avoid head removal.

 

Has anyone done a repair with a big sert on a 09 4.6l engine?

I am pretty sure the kit I need is #5141E, and the insert is #51407. Can anyone who has done a repair of a repair confirm these numbers?

I would like to order them tonight.

Wow, it's a pricey kit at $332, but a whole helleva a lot cheaper than $2200 I was quoted. Funny thing is, they wanted to take the head off to see if there was internal damage. I hope that there isn't any internal damage. How much clearance is there when the piston reaches TDC? I guess I could get an inspection camera to take a looksey. Looking down the tube with a flash light and a mirror, there doesn't appear to be any damage to the piston.

 

You can borrow/rent a borescope at some parts stores. You have to look at the valves for damage too.

I don't think I've heard of anyone else having to do a thread repair of any kind on the 8 thread heads, much less repair a repair!

I would call Timesert and discuss your issue with them.

 

If I had to hazard a guess, I'd think perhaps a plug was overtorqued into the head, stripping the original threads and that necessitated a repair. Now, why the repair has failed - is a 500# gorilla doing the work?

- Jack

 

I'd guess the exact opposite - seriously undertorqued.

 

You are probably right!

Didn't use a torque wrench. I am going out and buy one!

 

Really I dont think a torque wrench is necessary. I use a 3/8ths ratchet and tighten plugs the way I have for decades. As tight as I can get them with that ratchet. 26 lbs is pretty tight on a 3/8ths Pretty sure it reasonably close..

 

Would undertorqeing damage the threads? I can see it might let the plug back out if it was undertorqued in the original or repaired threads, but why would undertorqueing damage the original threads in the head?

Regardless, I'd certainly use a torque wrench. Clean the threads, and don't use any lubrication on them.

- Jack