I ran my poor little 81 300SD too long on too little oil and now Im fairly sure it has rod knock.
My question is; IS there anything I can do (IE Run a heavy motor oil) to help defer the rod knock?
I changed the oil and replaced 2 quarts of oil with Lucas Oil Treatment (Geez that stuff is thick!) and it has quited the rod knock, but you can still clearly hear it.

 

Thanks for your candor =)
That sounds reasonable, could I get away with taking out the crank, getting it turned and balanced, replacing all bearings and putting it all back together?

I've rebuilt a motor before to some success, but haven't just dropped the pan and pulled the crank before. But I imagine as long as you keep the pistons in place everything should be just fine.

Thanks in advance for you wisedom
James

 

This isn't the car you bought to run WVO in, is it? If that's the case, your problem could be much much greater than just a rod bearing.

 

It is that car, but I have yet to run an ounce of WVO through it. Rod knock is clearly from low oil condition / my own complacency for not checking it regularly.