I have a 1984 suburban with a mystery oil leak. I can drive it around all day until I get into some stop and go traffic and the engine temperature gets close to 190 (still safe but higher operating temperature). At this point it starts dumping oil at an alarming rate and the oil pressure goes down at idle to near 0. My oil presure sender is a little gummed up, so I'm sure there's still oil pressure but obviously a drop.

Any ideas? I can't seem to get it to replicate unless the engine is under load. Its obviously got alot of pressure behind it because it sprays everywhere and has a splatter pattern on the ground, not a drip. I don't see any oil coolers/lines, and the housing for the oil pressure sending unit looks bone dry. The oil filter is spotless as well.

What would be a normally small almost nonexistent leak until it hits the upper range of safe operating temperatures and under load?

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