Merc 470 engine noise VIDEO Please comment

[wrestling coach]

1982 Merc 470. This video is shot on a warm engine thermostat open 160*. Mobil 1 15w50 engine oil. Idling @ 500 RPM. I have the idle down to assist in trolling. Noise is virtually the same on a cold engine. Noise goes away as soon as you pick up the engine RPM's. Should I be concerned or not?


Dennis

 

[alldodge]

Re: Merc 470 engine noise VIDEO Please comment

It sounds like your hydraulic lifters. This may be happenging because you have the idle so low that it's not pumping enough oil to keep them filled. It this is the case other items might not be getting enough also. Would you think about using a lower pitch prop for trolling and make sure not to over rev on plane?

 

[wrestling coach]

Re: Merc 470 engine noise VIDEO Please comment

OK. Good point. I have a 21 pitch prop on it now. That's how I got it. How does the 470 get the oil up to the valve train? Through the push rods? Would you consider the 15w50 oil contributes to this? I am thinking a straight 40w Shell Rotella next season.

Dennis

 

[alldodge]

Re: Merc 470 engine noise VIDEO Please comment

OK. Good point. I have a 21 pitch prop on it now. That's how I got it. How does the 470 get the oil up to the valve train? Through the push rods? Would you consider the 15w50 oil contributes to this? I am thinking a straight 40w Shell Rotella next season.

Dennis

I'm not a 470 guru, so I'm not sure but most hydraulic lifters are pressurize using internal block passages, which then send oil up through the push rods to the rockers. I thinking it is lifter/rocker noise but this is just my opinion. Hope someone more familure with the 470 will add.

As for the oil I don't see much of an issue, and I've known of others which use diesel formulated oil in their boats without issue. I use my boat in mostly warm weather and therefore I use stright 40W. I don't crank it up if I need jacket.

 

[stonyloam]

Re: Merc 470 engine noise VIDEO Please comment

Yes the oil comes up through the pushrods.

 

[m_steiger]

Re: Merc 470 engine noise VIDEO Please comment

On these older engines with flat tappet lifters, I would run a conventional motor oil. Shell 15w-40 T3 Rotella is about the best thing you can run in these motors. I'd agree that it does sound like a lifter. No big deal, I would just idle it up to specification. Lucas engine oil stabilizer could possibly help out as well.

 

[wrestling coach]

Re: Merc 470 engine noise VIDEO Please comment

On these older engines with flat tappet lifters, I would run a conventional motor oil. Shell 15w-40 T3 Rotella is about the best thing you can run in these motors. I'd agree that it does sound like a lifter. No big deal, I would just idle it up to specification. Lucas engine oil stabilizer could possibly help out as well.

Yes I know of the flat tappet "solid lifters". I have a solid lifter C2 Corvette that needs the ZDDP additives so I don't wipe the cam. But somehow these 470 lifters are both "flat tappet" and hydraulic not "solids". The valve train noise does not really alarm me. I am just trying to understand this 470 a little better.

Dennis