3.0 Volvo penta flywheel and coupler bolts vibrating loose

[BrandonW89]

3.0 Volvo Penta. Can anyone tell me or has anyone ever had problems with the nuts an studs vibrating loose on the flywheel and coupler I purchased this boat used an just from the looks of new hardware it looks like the engine has been pulled before for whatever reason. The boat run fine all summer last year til right at the end of summer one of the studs vibrated out and was rattling around in the flywheel housing. I pulled the engine an found two or three studs coming loose also so order new studs an nuts and replaced them an torque them using lock tite because it look like none had been used before. Long story short wen I put the boat in the water yesterday it run great for the first 2 or 3 hrs pulling knee boards but wen I took it for a lil cruise for about 10 or 15 mins down river at around 3/4 throttle wen I stop to turn around I could hear like a rattling vibration at low rpm an take off but sounded fine at cruising speed about 1/2 throttle. But by the time I made it back to the boat ramp the noise had got louder an could hear it at idle before I got it loaded it on trailer I could hear a noise like one of the flywheel nuts had fell off it sounds just like it had done before. I haven't pulled the engine yet but I'm bout 90% sure the same nuts have vibrated loose. My question is what keeps causing this is it possible that the flywheel could have got warped some how by previous owner maybe? Any info would be greatly appreciated thanks

 

[youreekaa]

Wow, odd timing. I am in the middle of putting my boat back together after this repair. It's not a difficult job, and not too time consuming. I would estimate 2-3 days the first time through.

In my research on this problem, I did see in one of the forums that there was a "customer campaign" or something to that end about improperly torqued flywheel studs in that motor. it applied to certain serial number ranges of which mine was not part of for that year. sorry i cant point you directly at that information, but I'm sure you can find it with a little google-fu.

i used thread lock on mine with the thought that it should prevent re-occurrence. there was no damage to the studs or the crank, just 5 of 6 were loose.

good luck
John

2001 Larson 180 SEI; 3.0GSP-A and SX-M Volvo Penta

 

[BrandonW89]

Yeah it's definitely not a bad job I'm Gona try to pull the engine this evening but just some more FYI the boat has always seemed to have a slight vibration wen the engine is revved up in neutral not bad but more than what I felt like it should have. And a warped up flywheel is wat comes to mind now wen I hear it but maybe it's just me

 

[jerryjerry05]

You can run the motor while out of the boat to check the flywheel.

​Try to contact Volvo about the bolts working loose.