That’s the one ☝️ I put 386,000 miles on Oldblue with the same seal, no leaks.

 

I agree, looks like it would last virtually forever.

Donbrew, are you thinking of the oil filter cover O-ring?

 

I've had the same leak from the crankcase halves and it has leaked since 2015. Not enough to add any oil between changes but just enough to keep the bottom of the engine dirty.

 

If it’s from the front of the engine it might be the oil filter sending unit.

 

I didn’t know sucha thing existed. The first thing I thought of is, what color is it?

I have lime green fluorescent dye in my a/c, thought came standard in the refrigerant. (I didn’t do it.) Works great, helped me pinpoint a leak and decide not to fix it because it’s in the compressor housing, lol.

Seems the default color for these dyes is green. If put it in all the fluids, I’m thinking I want color choices!

Found this, promises not to change the color of the DexCool. Not compatible with other coolants. Surprisingly cheap. No idea what color it glows.

 

Just a fluorescent solution that glows in ultraviolet light.