Engine Rattle Noise

[AZ Boat Guy]

I recently replaced my fuel pump on my 2005 Volvo Pents 5.0 Gxi. When I took it to the lake for a test run the boat worked perfectly, plenty of power, all gauges in normal range and sounded great at all power settings. I then stopped for a while. When I restarted the boat I heard a rattle sound at idle coming from the left side of the engine. I also noticed a small water leak from the 4" line coming out of the left side of the engine (exhaust manifold?). Anyone have an idea what this rattle sound could be? Other than the rattle and small leak the engine runs fine. Thanks!

 

[AZ Boat Guy]

No Title

Here is a picture of where the noise and leak are coming from.

 

[jerryjerry05]

The water leak: could be the hose clamps need to be tightened.
Loosen and move them a bit and tighten.

The rattle? Could be a bad manifold riser?
Bad gasket?
Or the gimbal bearing?

You ever use a screwdriver stethoscope.

LONG screwey or a piece of pipe even a wood broom handle.
Start the motor.
Touch the tool in the area and put the other end in your ear.
Move it around and try to find the spot that the noise is the loudest.

If it's coming from the manifold? Pull and inspect???

 

[Bondo]

The rattle? Could be a bad manifold riser?
Bad gasket?
Or the gimbal bearing?

Ayuh,.... Welcome Aboard,.... Detonation is also a possibility,....

 

[AZ Boat Guy]

When I use the hose connection to cool the engine at home I don't hear the noise. Sounds fine. At the lake where lake water is cooling the engine I hear the noise at idle. At cruise, I hear no noise and performance seems fine. It seems like it has something to do with the way the lake water is being drawn into the engine.

 

[ericga]

Could it be the riser bolts that are not tighten enough? You may want to check if you have water in your oil (yellow goo on the filler cap or dipstick).