I have a seriously annoying rattle at idle (950-1000 R.P.M.'s). It sounds like the baffles are falling out of the headers. If I give it a little bit of gas and raise the R.P.M.'s to around 1200-1300 R.P.M.'s the rattle goes away. I thought that my flex plate was cracked, or that the starter was dragging on it, but as far as I can tell everything is okay with the flexplate and starter. I have been told by a couple of people that the stainless impellers rattle at idle, so I now have the pump apart and I have found that the impeller keyway seems a little loose, both in the brand new 17-4 shaft and in the berkeley stainless.
If you are running a stainless impeller does it rattle ?
Thanks in advance for any help or suggestions.