1994' Silverado Low oil pressure
 

I drive a 1994 Silverado C1500 truck that is lowered 3" in front and 5" in back (if dropping the oil pan is required). I got my oil changed 3 days ago about half a month after the date, but 400 miles before the mileage to change it. Today I noticed that my oil pressure when idling was around 20, when it is usually around 35-40. I checked the oil level and it was close to full, so I topped it off slightly hoping to fix the problem. It started up with normal pressure, but within 10 minutes was back to the low pressure when idling. Any ideas on what the problem could be? I have done some research and found it might be the oil pump, and was wondering if anyone had cost estimates for parts and labor or how hard/long it would be/take to do it myself. Any other possible sources for my problem would be appreciated~

Thanks for any advice~
Brett

RE: 1994' Silverado Low oil pressure
 

Install a mechanical gauge to verify the oil pressure. If the mechanical gauge shows the pressure is normal try replacing the oil pressure sending unit.

RE: 1994' Silverado Low oil pressure
 

I ended up taking my truck in to a Penzoil to get my oil changed, and it is now running better. No more convenient Wal-Mart oil changes for me. The pressure is now around 35 when idling as it was previously, so I believe that the problem has been fixed. I'mm assuming the "masterful" mechanics at Wal-Mart didn't put the right type of oil into it, despite the fact that the sticker I recieved said they replaced Castrolg GTX 25W50. Thank for your advice :D