RangerOne
Active Member
I just finished changing the oil on my 2007 Challenger. Before changing the manual says to bring the oil to operating temp and run at 4000 rpm for several minutes. I attempted this and at about 2500 rpm there was a strange rattling noise I think coming from the impeller, so I shut it down. Any ideas what this might be? Bought the boat last year and put about 10 hrs on it since purchase.