There is a good chance your exhaust manifolds need replacing if they havent been allready
Do you have aluminum valve covers? The shop that built my big block said not to run aluminum valve covers because they can cause condinsation from our cold water in the northeast, early in the season, cold water? just a thought!tcgravy said:Pulled the dipstick yesterday and got milky oil.
Engine oil was changed at the beginning of season, boat has been ran 4 times since then without any problems.
Engine has been running just fine, absolutely no problems and wouldnt have noticed anything without checking the dipstick. It was ran on a hose /muffs before last outing and the muffs fell off, had to replace impeller - don't think it overheated, wasnt that long and only at idle, but not sure.
1987 5.7 350, 4 barrel carb, engine was rebuilt 2 yrs ago by previous owner. thru prop exhaust.
My question is where to start....I've done some reading and am looking at exhaust gaskets being the first place to check, then head gasket, also intake. Have never worked on boat engines before, but I'm ready to get this thing back in the water.
Thanks for the help in advance.
I would check out All the valves , seats & guides and also check the push rods for staightness, and the rocker studs if their press fit, if you had any hydraulicking. since now is the time to be thorough while it's apart..tcgravy said:Head disassembled today:
No water in cylinder #5, but the piston does seem to have some buildup on its crown.
Any ideas on what is going on with cylinder #5? (low compression, 90) Put oil into the cylinder (before tear down), turned it over, and compression didnt change. This points to valves, not rings, but could it be something else?
You can pull the manifold and head, have it ground and replace the bad seat/valve for around $200.00 total including the machine work. I wouldn't ruing the whole season over that.tcgravy said:Yea - leak down on #5 revealed leaking through the carb, meaning its something with the intake valve on that cylinder.
Probably not going to get fixed until summer is over....
thanks for the help guys