99 Suburban C1500 LT 5.7 130K Miles While in park I can rev the engine up to 4-5K no tick whatsoever and runs smooth, but under load in drive it sounds like a tick. I did an engine flush and put in fresh oil but it's still there. Dont understand why it does it in gear but not in park unless its something else. If I am in gear and I ease on the gas you wont hear it, but the harder I get on the gas the more you can hear it. It's not a CV joint type noise. I would swear it was a valve ticking. Any help appreciated. Also... my oil pressure sits at 10-12 PSI at idle and will go up a bit over 40 on a moderate accel. Is that ok?