Odd Knocking sound

[dz09x]

93 SSEi

Weird knocking sound coming from the engine at idle, 800 rpms.
The knocking continues and gets louder up until 1400 rpms, It completely disappears afterwards.
Place the car in drive, there is no knock at idle, or at higher rpm. there is slight tremble and shake though.
Put the car in park, no noise at idle. But if i tap the gas then the noise returns at idle.
No Service Engine lights what so ever.

Completely stumped. I am taking a guess that it isn't a bottom end issue. More sounds like a top end issue. Maybe? Could it be maybe too thin of an oil in the engine? Is it possible that maybe one on set of valves is not getting oil, but is getting oil at higher rpms. Possible blockage somewhere?

Also, don't know if it matters. This car is having transmission issue, where a few solenoids have to be replaced.

[nickdalzell1]

mine has been making the same hammering sound it's made since i bought it at the junkyard a couple years ago. i think the 3800s just make noises. if your oil pressure is good and it doesn't sound like a bearing i'd just ignore it. i did manage to quieten mine down a tad by tightening the lifters while i was replacing the valve cover gaskets though.

[RJolly87]

Can you get a video of the issue and post it?

[nickdalzell1]

could also be the harmonic balancer. i had a Buick that did that once. when it goes it sounds like an engine knock or rod knock and is scary.

https://www.youtube.com/watch?v=FCeMx18P2aM