Hello, I am having trouble diagnosing this noise. It is not the belt or the water pump, as I have removed the belt and fired it up again with the same results. It does have oil pressure, but not much. I have had the car almost 1 month, and after fresh oil and plugs, this is what its doing. The noise appears to be louder on the passenger side, as well as coming from the top. Any suggestions on what to look into? I'm hopping its not the crank bearings...but it does sound like metal on metal. Car is a 1973 240Z with the L24 motor. I do plan on rebuilding the carbs (ZTherapy) whenever I can get this issue resolved. The motor does crank just fine, this is my first S30, I am more familiar with the Z32s, but I have always wanted a S30 ever since I was a child.

https://www.dropbox.com/s/793lnz7uj6...ngineNoise.MOV

Any ideas/suggestions would be greatly appreciated.

 

Could it be the mechanical fuel pump?

 

Steve, what in the fuel pump would make such a noise? Its pretty loud..I will take a look at it to rule it out...

 

I can't play the sound file on the computer I am using right now, so I don't know how bad it is.