The car runs normally and doesn't have a check engine light. What could it be? It's a 2003 350z with 149k miles

 

Assuming you have oil, it's likely the oil pressure sensor. It's a fairly common problem and an easy fix.

 

I know the HRs do, but do the earlier models have the gallery gasket?

 

Ok I researched it and answered my own question. Replace your gallery gasket. Point blank period. That is the problem. Trust me, I did it and it was a pain in the d!ck but that's a piece of mind out of the way. Use Z1's gallery gasket and Nissan's rtv. Literally only things you have to buy unless you plan to use new oil, coolant, and power steering fluid. You'll have to drain all 3