Have a 1982 300SD that has been making a knock/banging noise. The noise is only preasent at higher RPM when the engine is warm. Wondering if this could be related to oil pressure as mine does vary (high when RPMs are up and low when RPMs are low. The noise is quite significant. Has anyone had experience with this?

Thanks.

 

The noise is clearly related to the engine/transmission area, it only happens when the engine warms up, above ~1700 RPM. It is rythmic with relation to the engine RPMs. When probing the noise with a stick, it seems like it may be close to what I think is the oil pump (beneath the oil filter), or the transmission bell housing. Hard to tell as these components are close. One added note, when I changed the oil last it made the noise momentarily when it was first started cold, but only when the engine was reved. The car also seems a little sluggish. Is there something inside the oil pump that could be knocking/banging, or is there something inside the trans bell housing that could knock/bang. Pretty loud.

Any direction........Thanks