I have a 97 crownline with a volvo 5.7 gl last year I had a mystery leak #3 ended up with water in it, pulled the head off and was able to free the engine and loosen the rings put everything back thought it might be the exhaust manifold so I went on ahead and replaced them, been running fine ever since, this weekend when I tried to go on plane engine had no power and at times seem to flutter like when you over rev and the lifters flutter this was at about 4k, temp was fine backed off the power hit the trim-tabs, tried to get back on plain no go this time the engine started hissing I looked at the temp and it was nailed so I shut it down, waited for it to cool, no go hydro lock, got towed it next day I pull the plugs and cranked it had water in 8 and 7 and 1, poured some wd40 down the crab =cranked it over a few times then ran a compression test all tested at 225 psi + or - a few pounds, put the plugs back in and restarted it ran fine only for a couple of seconds had no water in it, pulled the intake off noticed that the bolts were loose and light rust seeping in through the gasket, reading up seems that this may be a common problem with the 350’s any input on this being my mystery leaks, also found the the raw water pump went out on it that’s why it over heated the lack of power is still in question. All feedback welcome and appreciated
