SVTguy1990

So this isn't for my truck. My friend has a 2006 F150 with the 4.6L pushing 220,000 miles. About 10K ago he had a plug back it's way out and destroy the threads and coil. It was repaired and ran perfect after that, until last night. While he was driving home it made a loud pop and that spark plug shot out of the hole ripping all the threads out with it and destroyed the coil. The plug looks like someone took a 5 pound hammer and beat the out of it. I'm guessing at some point it began failing to fire, as gas built up it detonated causing an overload of pressure. My question is can we re-thread the head with a bigger insert even though it's already been threaded once before? Most shops are saying for the price it's worth just replacing the head. Out of the 5 shops none were willing to re-thread it and wanted around $1400 to replace the head. Does anyone know of a kit I can purchase to do this, or should he just buy a junkyard engine? Any help is appreciated!!!!

Martian

Moved to 2004 - 2008.

650NutKase

the original repair was most likely done using a helicoil. Those are usually one time repairs. I've never heard of a 2nd helicoil being done, not saying it cant. I'd personally look for a good, used head to replace it with...sorry bud.

SVTguy1990

Yeah that's what I was thinking. Luckily it's not my truck, I think for the amount of miles he has and the value of the truck it may be better for him to just cut his losses and get a newer one.

650NutKase

Depends on how much he likes it. could be an excuse to put a nice head set on there and cam it.

Moremoney

x2

For the cost of the head it might be cheaper just to find a replacement 4.6

k_h

Try looking into a Time-sert kit. Way better than a helicoil.

4.6owner

If someone used a Helicoil they didn't do it right. You need to use a Time-cert. They are the most reliable for the temps and pressure the plugs endure.

SVTguy1990

I'll look into the time-certs, I'm just not sure there is enough aluminum left in the hole to thread. I've been looking for engines but I can't find a good one under $1000. I told him to sell it like it is and cut his loses.