1997 J30 with 108K - After a brisk entrance on the highway, the oil light came on and stayed on. Got off immediately and heard that nasty valve chatter so not a sending unit false alarm. Oil level was good. Limped it to the Nissan dealership. Mechanic said it looked to have some buildup so they're going to drop the pan and thoroughly clean. He said if that doesn't work, I'd need a new engine. Not going there so what else could one reasonably do to solve the issue? Oil pump? Engine flush? Never had a flicker from the oil light before and never heard any noisy valves. I'd rather not junk the car until I've exhausted all options. Thanks!

The only things that cause oil sludge are ignoring the 90 day change interval and using low quality oils. With a higher quality oil you can stretch interval to 6 months as long as you don't exceed 7500 miles.

Once sludge is there only manual cleaning works..........total disassembly/

The cleaning labor ends up costing more than a JDM takeout engine swap.