In preparation for the trip to Hershey this weekend, I wanted to troubleshoot some very poor cold starting that had developed recently. To check the health of the CHT sensor I pulled it so I could verify cold and warm readings. Odd thing was how much effort it took to remove. I'd read these things should snug but not be in very tight. So I finally got it out and this is what I found:

Click to view attachment

I'm no expert but that sure looks like aluminum filling in the threads. I have a correct replacement but I'm worried about trying to thread it into the head at this point.

So my question is how screwed am I now and what is the best way to go forward? Any thoughts or experience in this area would be much appreciated.

Thanks,

John

You are not in error ... those are the aluminum threads that pulled.

Someone makes a setup to install the CHT on one of the intake manifold bolts, but I don't remember whom.

You you can try (try!) to get a helicoil into the hole without dropping the motor. Not easy, but I have heard that it can be done.

I dropped the motor when it happened to me. And then I found a few other things that I should do "while I'm in there"...

--DD

This happened to me and I dropped the motor! Way easier!

I have a core motor that came with a CHT spacer that acutally screwed into the tin screw hole by the intake manifold. Thankfully it doesent need to be in that exact spot, just anywhere in the head that it can get proper heat transfer and grounding. This should not keep you out for long.

Also - if you need to hack something together to get you going a potentiometer (variable resister) can be used to manually simulate the CHT sensor. Think of it as an electric choke. It's a bit of a hack, but it would certainly get you on the road if you needed a couple of days before you had time to drop the engine and do the fix correctly.

Go to lowe's or home depot and in the hardware section they have various sizes of snap in plugs. You've seen the larger ones on SS sinks where an extra hole is covered up. Buy one of the 1" plugs then drill the appropriate sized hole in the tin above the CHT location. Drill, tap and helicoil or time-cert it. Place a small bead of silicone around the plugs edge for an airtight seal, before snapping it in the tin.