I have a 2000 Sport with 112k on the clock. I bought it at 106k. I've owned it for 1 year. It's a 4.L. I use 5w30 oil. There is a noise from the engine that's recently become more noticeable. It sounds like it's coming from the lower part of the motor. It doesn't sound like the tapping/clicking of the valve lifters. It doen't sound like the rapping noise of a main bearing. It's most noticeable when the Jeep is first stared cold or after it set a while from being driven. When I accelerate the noise goes away. After the engine has been on for a couple of minutes and before shut down, I can't hear the noise. The oil pressure when cold is 60. When hot, 2 ticks from zero. Engine heat at mid point. Any ideas? Thank you

 

What brand of oil filter are you using?

If your Jeep has an automatic trans, your flexplate to torque converter bolts could be loosening up.

 

If it happens especially during warm up and sounds like your engine is a diesel, it's a common thing among Jeep motors. Every single Jeep I've owned (on my 3rd XJ and 4th Wrangler) has done it.