BMW Repair: possible rod knock?, tick tick tick, rod bearings

Question
hi there, i have an '85 325e with 250 000kms, 5speed.
i purchased this car knowing it needed some work so here is one of my problems.  It has a "knocking" sound beyond the normal tick tick tick of valves.  It almost sounds like a diesel at times.  The noise is more noticeable from idle to 2500rpm.  I tried a stethoscope on the block and on the oil pan but it only sounded like moving parts, not knocking parts.  The plugs, cap, rotor, in tank fuelpump and filter have been changed recently.  The outboard fuel pump is a bit noisy but i dont think its related.  Its been suggested that my rod bearings are worn and need replacing.  The car seems to have normal power except for a little flat spot between 3000 - 3500 rpm.  Any suggestions would be greatly appreciated.


Answer
Checking the oil pressure would help determine if it is bearings or not your oil pressure will be very low.I would look more into the rocker arms being worn,wether it be the pads or the rockers on the shaft.
Does it have any oil leaks?or weeps?If the oil is leaking anywhere it causes drivability problems.The reason I ask is if the oil pan is leaking it would be the time to inspect the bearings if that is a thought by using plastigauge.The clearance in between the bearings IS what gives you oil pressure,so now would be the time to check it.