My 2002 Chevy Silverado with 5.3 is showing low oil pressure in the past couple weeks. The gauge in the dash indicates 40 down to 30. High speed it indicates 40. Idle it drops to 35 or so. I use synthetic oil. Oil level is correct. No oil leaks.
What do I need to do about this?

 

What's your mileage? My 93 with 350k+ mi drops to 15-20 when warmed up and highway speeds, and as low as 5 at idle! Runs great, needs oil only every 1500-2000 miles.

 

30 is not low. What was it before? you did not state.

http://www.silveradosierra.com/vorte...6.html#p121043

 

M10027m: Welcome to the forum.

 

M10027m Welcome to the forum...
Your range sounds fine... oil pressure will drop with age and mileage due to mechanical wear of the engine and its components including the oil pump and bearings which all will eventually contribute to lower oil pressure...
as Rednucleus points out it can drop as engine speed decreases but goes back up correspondingly with RPM... keep in mind also that the gauge can be erroneous, if you are hearing knocking or clatter I would suggest having the pressure checked with an external gauge ....

 

185,000

 

Think your pressure is great for that mileage.