The OE sensor is a tapered pipe thread, so it tries to wedge the threads open. Not an easy repair normally. What I have done is to get a tap in the correct thread (three eights -18 if I remember) for a straight bore. Then you tap the block in that thread with grease on the tap. Now you clean the hole out very well with a solvent. Next you get an adapter for that thread to the 3-8ths pipe. Next you clean the hole again, Screw in the sensor until it just shows the crack and apply Loctite into the crack. Remove the sensor and screw it into the adapter fitting. Now apply Loctite to the threads of the adapter. Screw in the adapter until it is through the threaded section of the block wall. Now let it set overnight. The idea is that the Loctite seals the small crack and the threads on the adapter and with it screwed in to cover all the threads it should seal the area. I've don't it a few times with good luck. The issue with pipe threads is that they leave an open path that can leak so you tighten them, and they wedge apart the hole to seal. The straight adapter won't try to wedge the threads open so it shouldn't leak. The other option is to have someone TIG weld it back together but on a used block that can be difficult due to the oil and dirt.
Sunday, February 23rd, 2025 AT 10:31 PM
