I am replacing head gaskets in my new to me 03 4.6l, overheating with loud tapping which I assumed was a slipped sleeve. Tore into the top end and pulled heads. Found a large coil of Helicoil ( from a bored out spark plug hole on cylinder 6) made its way into the piston area and tapped a lot of holes in the head! See pic


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My QUESTION IS- SINCE THIS IS NOT A SEALED AREA IN THE HEAD, meaning it's clear of the gasket, is it fine the way it is??

 

My question is...why would you want to reuse a head that has a heli-coil in it to begin with...since a piece of it has already fallen into the cylinder chamber once...why would you risk it again? Get a new/used head and replace it. Where are you located, maybe someone close by has one or could ship cheaply, also, non SAI or SAI?

 

It shoud be fine, but a replacement head would be preferable. I'd you reuse it, 3 important things:

First, also check the valve seats. My guess is they never got impacted, but good to make sure.

Second, JB weld the outside threats of the replacement helicoil. Fix it on the bench, obviously, so when you break the tab off it's not in the cylinder.

Third, if you have any helicoil overhang in the cylinder, take a sandpaper disc on a die grinder and smooth sand contour it down to be flush in the head.

 

All those little divots are going to be excellent places for carbon buildup inside the cylinder, no? Potentially leading to hotspots and pre-ignition.

 

Won't be a problem since they're recessed and the truck is computer controlled. No worse than the raw casting of the combustion chamber.

 

Looking at that its probably best to replace the head and gaskets, but if you don't the the heads needs a skim, and a new gasket minimum, if you need to take off more from the head it may be possible to get a thicker gasket to get the combustion chamber back to a reasonable compression ratio

 

Thanks to all for responding. I actually have a spare d2 with usable heads, but from a 4.0 non SAI (this one has SAI). I'd have to delete the sai which I've never tried. Plus my spare is running fine, just a little sad to look at.
I may just find the best way to fix the plug bore on the bench, since the rest of the head is in pretty good shape

 

I would not worry about that little bit of deck damage, although the helicoil plug threads may need attention. Heads are pretty cheap though, especially SAI heads. Might want to check with the local breaker.

 

If you're anywhere near Illinois, I have set of SAI heads I don't need and would sell dirt cheap.

 

That deck could be welded up and machined back down right?