1987 Porsche 911 — metallic rattle for a few seconds after cold start

I'd want a measurement, not a hunch. Move a coil or plug on the 1987 Porsche 911 if it's cylinder-specific and see whether the code follows. You'll know quickly if you're on the wrong tree. If they can't show the line item, I assume it's hiding. Only after sitting overnight so far.

This is usually cheaper to test than to guess. Move a coil or plug on the 1987 Porsche 911 if it's cylinder-specific and see whether the code follows. You'll know quickly if you're on the wrong tree. Time, temperature, and whether it's in gear are the notes that actually help a shop. I'm in no rush to be a hero on it.