Rattle in Fuel Tank

Forfun1960 · Posted: Thu Jun 04, 2020 9:48 am Post subject: Rattle in Fuel Tank

I have a 23' Cape Cruiser with 2-30 gallon Aluminum fuel tanks. The port tank has an intermediate rattle inside the tank. Seems like it is mostly at idle. Rattle takes place no matter which tank I am using. Wonder if anyone has seen or heard of this issue before? Not sure where to do anything about it or not boat runs find.

tsturm · Posted: Thu Jun 04, 2020 11:54 am Post subject: Re: Rattle in Fuel Tank

CC Rider · Posted: Thu Jun 04, 2020 3:19 pm Post subject:

I too have a 2006 Cape Cruiser and both of my tanks have made this noise since I have owned her. I had a problem with my engine once, and thought it may have been a plugged fuel line pickup and so I removed the pickup and had a look to find nothing in the tank. And by the way, there is no filter on the end of the pickup tube...
The noise is strange, it only happens at engine idle, and only when I first start either the main or the kicker. (Both engines are connected to the tank(s).) I have come to the conclusion that it is either the fuel gauge floats that cause this, or more likely a little air in the pickup line is making the noise.

Chris

ssobol · Posted: Thu Jun 04, 2020 5:14 pm Post subject:

Couldn't also just be resonance somewhere? There are things on my boat that resonate depending on engine RPM.

CC Rider · Posted: Thu Jun 04, 2020 6:53 pm Post subject:

Forgot to mention that there is a check valve with a small ball bearing located at the elbow at the top of the tanks. Now that I think about it, this is the most likely culprit as the ball probably rattles back and forth with low fuel flow (at idle), but not when the flow is greater (anything above idle).

Chris

Forfun1960 · Posted: Thu Jun 04, 2020 8:40 pm Post subject:

Thanks Chris, Glad to hear others have a similar situation without issue. This winter I might pull the tank to satisfy my curiosity.