Mercruiser 3.0 MPI rattle noise

Bomoseen802

Recruit
Joined
Jun 18, 2021
Messages
3
Hello everyone, new to this community and have loved all the resources available so far. Thank you all for sharing your knowledge.

My father and I bought a 2014 Monterey 186FS. It is well taken care of and has a Mercruiser 3.0 MPI. So far it it has about 10 hours on it since we bought it. Smooth and no issues, until yesterday I went to start it up and heard this noise coming from the engine.

Hoping someone can help me find where this is coming from or where to start going through a checklist. I do not believe it is the lifters/valves, but more of a rattle/loose belt or something else (hoping anyway).

All fluids are new and levels are good. This noise started out of no where, the last time we ran it, it was quiet and smooth. One thing to note, is when I started it there was a brief squelch (sounded like a fan belt), but stopped after it was running for a few seconds.
 

Attachments

  • IMG_3992.MOV
    1.7 MB · Views: 0
Last edited:

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
42,961
Might be gimbal or U joints. Pull the drive and connect a hose to the thermostat housing so it can be run without the drive
 
Top