Disturbing vibration / noise at idle speed on 2004 Penta (GM) 4.3 V6 I/O in my 190 SSI…

[Dawg82]

Doesn’t seem to affect performance at high end…anyone else run into this? (See video)

 

[Denny]

Maybe a loose tappet

 

[Dawg82]

Thanks for the suggestion.

 

[Iggy]

If it was my boat? I would open the engine compartment with the engine running. Do you have the noise in gear? At lest that would tell motor or outdrive. If the outdrive, have you check the oil level? Than go from there...........

 

[drewm3i]

Sounds either like an exhaust flapper or possible lifter.

 

[Denny]

Is it just a tapping noise, or an actual vibration?
When I first got my girl I had a flapper go bad. It did not sound that intense, it was more like a marble rattling in a metal can.

 

[Dawg82]

Thanks for the replies. Been traveling and site locked me out. It is a more of a fast tempo “chug, chug, chug” with vibration

 

[drewm3i]

Thanks for the replies. Been traveling and site locked me out. It is a more of a fast tempo “chug, chug, chug” with vibration

Post another video with the hatch open and the camera nearby the valve train. Then a second one outside of the boat near the transom assembly exhaust ports.

 

[Denny]

Thanks for the replies. Been traveling and site locked me out. It is a more of a fast tempo “chug, chug, chug” with vibration

Does the tempo get faster as you increase rpms, or does it go away?

 

[Dawg82]

Going to try and post additional video when up at the lake later this week. The noise and vibration go away when I increase rpms. It has occurred in forward, reverse and neutral at idle/low rpms

 

[Denny]

After researching the net, I think that you need a good mechanic personally there to check it out. There are too many variables to consider.
warn gears, timing chain, bad spark plugs, low oil pressure, lifters.
How many hours are on your engine, and how hard do you run it?

Engine Knocking At Idle Goes Away When Accelerating

Engine knocking is generally a sign of poor combustion and uneven fuel burning. In the beginning stages of damage, the sound will only be apparent during low RPMs or when the engine is idling. Once you speed the car up, you won't hear the knocking sound.