Hi guys, I just bought a 2004 Tahoe, 5.7L, with 192,000 miles. The fluid and filters have been changed every 2-3 months since new. Everything was working fine until tonight. Got in and started it and the screen on the dash read LOW OIL PRESSURE. The gauge read about 10-15 at idle and dropped to about 5 when I raised the engine to about 1500RPM. I let it warmup a little and the warning would come and go but the pressure never got above 15. Ive checked the oil level, not sure what to do next. Is this a common problem? Thanks for your help!