2001 Cobalt 190 Volvo 4.3Gi noise / problem

[M_Dennis87]

I recently bought a 2001 Cobalt 190 with a Volvo 4.3Gi and DP-SM outdrive as a garage sale special for a project. Bought it from the original owner. Fresh water lake boat in NH it's whole life. Owner died 3 years ago and the boat sat. I literally bought it at the estate sale for short money knowing that if I had to put a couple bucks into it I'd be alright.

I've gone through it (new battery, fluids, fuel, filters, fuel pump, impeller) and finally dropped it in the water and there's a pretty nasty noise coming from the rear of the motor. The noise didn't start in until after I had it up on plane at 20-25 mph. Now the noise is continuous. The engine starts right up nice and smooth (no smoke/misfiring/shaking) so I don't think it's the actual motor, but the noise happens in neutral and drive, and increases frequency with RPMs. Boat goes into gear and will move. Gimbal bearing? U-joint? Flywheel?

I've linked a video of the noise I'm talking about. At this point I'm just hoping it's not the engine or the flywheel because I really don't want to pull the motor...

 

[CraigATL]

Have you tried lubricating the gimble bearing? There should be a zerk fitting on the starboard side of the outdrive, about an inch or two away from the transom.

 

[M_Dennis87]

I have not lubricated the gimbal bearing. I'm thinking no matter what it should be inspected as the maintenance history of this boat is totally unknown. For starters I'll lubricate the gimbal bearing to see if there's any change in noise. Thanks.

 

[Lou C]

Responded to this on the Hull Truth. If it has the grease fitting on the side of the transom mount (starboard side as you face the stern of the boat) you can try pumping grease in while the engine is running on the water hose. If the noise changes or lessens or even disappears, then that's the source. You said on the hull truth that it does not change when you turn the steering port or starboard or tilt it up, correct? That would suggest its not the ujoints. But you won't know for sure till you pull the drive off. If the drive to pivot housing area and the gimble bearing are not corroded, they usually come off pretty easy but it can be a battle for sure. Where I am in salt water you MUST pull it regularly or else. Even outboards can have this problem due to the driveshaft splines seizing in the powerhead.