So my buddies boat milkshaked and he took off the valve cover and intake rocker was off, would this be the cause or results of milkshake. He going to take the top end of off this week.

Exhaust ?

Head Gasket

Yes to both. More investigation is needed to see what caused what.

So....next step is to determine why rocker fell off. They don't just do this.

Is it's pushrod bent or broken ?
Is the rocker broken ?
Is the lifter broken ?
Is the valve stuck ?
Is it simply the rocker arm nut turns loosely on the stud ?
Did someone semi recently adjust the rockers ?

There's more but I'll stop here for now.

Can't compress water?

More info please.....

Exhaust manifolds pressure tested ok, gonna start digging tonight or tomorrow, he thinks it's a head gasket. I'm sure there's more than that now. Thanks for the responses, I'll update as I find out

Is this engine in a performance boat ?

Reaon why I asked, I was hoping you said yes. And then I was gonna ask what motor, hoping you'd say some low hp black motor, and then I was gonna reply with a much bigger and radical engine as a fix.

See he's got that covered.

LOL.

How many hrs on the engine and is it HR or SR ?

25 foot warlock, 558? Paul phaff engine.