'87 325 rod knock or need valve adjust

[Jon K]

My mom bought an '87 325 in great shape. Had the timing belt done, etc. It has like 245k ish miles. Seems fine though. However last night I was replacing her head light bulb and noticed a very slight tap/knock. It was very loud at all, and could just barely be heard over the car running though it took me a few minutes to get my mom to even hear it while running. I don't know when the last time the valves were adjusted - we've owned the car for prob... 5 months or so. So should I start worrying about rod knock on the 2.7 eta or am I hearing a noisy rocker or something? Is there a good way to determine what's going on? These SOHC cars are new to me.

I should say that the car drives fine it seems and you can't hear this noise from in the car. At anything over idle outside of the car hood up, its hard to hear if at all audible.

Thanks guys