Well, I'm stumped right in the middle of an engine rebuild. The previous owner put a threaded adapter in the driver side head for a coolant sensor. Now, normally this isn't an issue, but this one has no nut or hex area to get a wrench onto. Its completely flush with the head, so I can't get ahold of it. The hole's too big for bolt extractors and the pipe extractors I find are either just too small or way too big. Any suggestions? I swear I've seen some kind of expandable tool I could insert and twist to grab it from the inside, but I could be wrong.

 

ok, if it's an adapter in the cyl head, it's going from 1/2"NPT down to 3/8"NPT or something?? Just get the biggest bolt extractor and use that.
I had to do this very same thing a few weeks ago on my daily driver. I had a 1/2" NPT fitting snap off in the intake, and had to buy the big bolt extractor and pull it out. It's about a 1/2->3/4" ez-out - the biggest one they sell in normal stores I believe.

 

well, just came in from giving it another shot. got the biggest extractor I could find and it looks like i wasted $15 (this thing is huge). adapter won't budge. Looks like I'll be trying to drill it out if I've got a bit big enough.

 

we always use an extractor, but we have a variety of sizes and they are old ones from napa i think back in the old days when they had interesting tools like this. hmm..

we often have to use one on those quick connect heater core hose line fittings in the intake of the back on the 4.3L and 5.0L and 5.7L intakes
they commony corrode and break off flush in the intake.


try machine shops ? maybe they have something you can borrow ?

hmm..

 

I know exactly the one's you are talking about; we used to sell a ton of them at my last job.

I'm gonna get out the dremel and see if i can remove a little bit of the meat in one area and give it another go. Worst case scenarion, I'll bring it down into my work shop and try and carefully drill out as much as possibly on the drill press. Gonna need to buy some new bits I guess.....

 

good news. the dremel deal worked. however, it looks like i made the threads a little messy. any ideas what the thread pitch/size is for that spot?