My 1974 has been in shop for 8 months. Since I have other car projects ongoing, I wasn't pushing them to get done, but now I am ready to bring her home.
Last item I wanted done was to check and/or change the CHT sensor. I called to see how they were coming along, and the report the CHT is broken off, and they need to drill it out.

Is there a better way to extract a CHT sensor?

At this point, it's just like any other broken steel fastener threaded into aluminum. They may be able to weld a nut onto it, or they may be able to use an extractor, or they may need to drill it out. Not much fun in any of those cases.

--DD

its not steel.
Easy to drill out and use a flat bottom tap to clean up the threads.
Alot easier if the motor is out....possible with a right angle drill if its still in the engine bay.

Rich

If the sender isn't steel, what is it? I remember it at least doing a very credible imitation of steel if it isn't....

--DD

brass, white metal not sure...

It cant be welded to....at least that is my experience.

Rich

It is neither fish nor fowl.

It looks like steel and it will rip the aluminum threads, but Rich is right, you cannot weld to it that I have heard. That seems to me to imply case hardened steel that is heavily nickel plated? Cheap German metallurgists! Same guys that gave us the 914 door flaps.

The body on a CHT is steel, but cheap, and it may be a hard alloy, but not great for adherence by hot metal. One form of welding over another may work, but typically shops will go cheap and try to get an ez out into the hole. There is no ez out made that will be long enough to reach in and still have it poke out of the tin far enough to get a crescent wrench on. Sounds like a custom carbide tool is needed.

I used to be a gunsmith, and some forms of thick nickel plating on guns made them hard to fix the cracks in preWWI handguns (ugly mofo's typically) without scarring the weapon. I have owned, shot or fixed about everything made since 1890, so I have seen some crazy metals.

Many of us know it is a total ballbuster to get the CHT in, and many of us have made tools from cut deep sockets.

It seems nearly impossible that they broke it off. We will want to see what they come out with. Maybe you could ask to look at the part that they broke off? If it broke at the top of the threads, that is really going to be a hard one.

Trouble is that to get it out with conventional means, the engine may have to be dropped.

GOOD LUCK ON THE EXTRACTION.
John