89 4x4 with the 2.4 8 plug has a valve like rattle when I get into higher rpms right before I shift....Any idea? Bearings?
It's definitely not spark knock or anything lose....I can hear it holding throttle around 3k rpms
Thanks in advance

Does the engine rattle when first starting? Possibility timing chain is loose or guides are wore. My first check would be look for a cracked exhaust manifold. You can’t always hear the noise with the engine at idle. The heat shield makes visibility seeing a crack difficult. I wouldn’t recommend removing the heat shield unless you are absolutely sure. The bolts that hold the heat shield in place easily break off. Can you tell where the noise is coming from? Could check oil pressure with a positive oil pressure gauge. Might be a rocker problem? A cheap thing to try is add some marvel mystery oil in the crank case.

How many miles?