5.7 boat engine help

[kpc01]

So I bought a boat with a Volvo penta 5.7 that was said to have a cracked block. Just tore most of it down and the waterpump came off and drained a ton of water. manifolds were perfect and when I took out the plugs I had water in #7 only. can I do a compression test to see if theres a crack?

I'm wondering if its just a head gasket and trying to avoid pulling the whole thing if I can help it.

[Rreemo]

If it's had water sitting in that cylinder I'd be pulling at least that head off of it for a visual inspection....at best you've got a blown head gasket, which means it's going to have to come off anyway, however at worst you have a broken cylinder wall, which of course you know the rest of that story. In either scenario it's had water in that cylinder not coolant (unless its a closed system?)....which means there is a rusty mess in there too.

Was this due to freezing without winterizing, or just suddenly have water in a cylinder?

If it was frozen I hate to be the bearer of bad news, but having had a relative amount of experience with boats, it's usually the block.

[kpc01]

If it's had water sitting in that cylinder I'd be pulling at least that head off of it for a visual inspection....at best you've got a blown head gasket, which means it's going to have to come off anyway, however at worst you have a broken cylinder wall, which of course you know the rest of that story. In either scenario it's had water in that cylinder not coolant (unless its a closed system?)....which means there is a rusty mess in there too.

Was this due to freezing without winterizing, or just suddenly have water in a cylinder?

If it was frozen I hate to be the bearer of bad news, but having had a relative amount of experience with boats, it's usually the block.

I got one head off today and hope to get the other off tomorrow. there was some nice rusty water in all cylinders just #7 piston was up and I was being hopeful lol. cant find any noticeable water in the oil but will pull my other head and take them to the machine shop to get checked out.

I bought the boat as is so don't know how/when it broke so assuming block myself but can't find any visible cracks yet so hoping for a head gasket. I plan on cleaning up the cylinders and getting the heads checked out asap. any advice on how to turn the crank by hand? theres no bolt like a traditional car because of the impeller...

[YALE]

You can't turn it over from the side with the accessory drive?

[shumpertdavid]

My experience was like yours. I had water in # 4 when I pulled the plug and all even cylinders had some water when I pulled the head. #4 chamber on the head was cracked all the way across.

[kpc01]

so far I haven't found a problem and have pulled both heads. tomorrow hoping to turn it over and look at the cylinders. Don't see any issues with the intake but heard they have issues sometimes. Tomorrow I'll look in the cylinders and see what I can find out.

[Chili]

If it's had water sitting in that cylinder I'd be pulling at least that head off of it for a visual inspection....at best you've got a blown head gasket, which means it's going to have to come off anyway, however at worst you have a broken cylinder wall, which of course you know the rest of that story. In either scenario it's had water in that cylinder not coolant (unless its a closed system?)....which means there is a rusty mess in there too.

Was this due to freezing without winterizing, or just suddenly have water in a cylinder?

If it was frozen I hate to be the bearer of bad news, but having had a relative amount of experience with boats, it's usually the block.

Don't pretty much all inboard / outboard boat motors draw water in for cooling?

I'm far from knowledgeable but recall that those that my dad had always required those headphone type things on the outboard with the water hose hooked up when running it out of the water. (Which we usually did after fishing in the mouth of the Columbia River, to clean it out, since it was salt water there).

[shumpertdavid]

Don't pretty much all inboard / outboard boat motors draw water in for cooling?

I'm far from knowledgeable but recall that those that my dad had always required those headphone type things on the outboard with the water hose hooked up when running it out of the water. (Which we usually did after fishing in the mouth of the Columbia River, to clean it out, since it was salt water there).

There are some closed loop systems, basically, the engine portion has a separate system that uses antifreeze. There is still an impellar or sea pump that circulates sea water to a heat exchanger to keep the engine coolant at bay. It's basically a liquid to liquid heat exchanger. The advantage would be the lack of salt/rust/minerals from the sea/lake water damaging the cooling system internals of the motor.

[BP]

If it were the intake you'd have intermix. I'd lay a straight edge cross the deck surface and make sure the heads are flat as well. If it's a head gasket you'd see where it's bypassing, look closely at the fire ring and the area where it goes to the coolant passages. You'd see erosion of the gasket between these two points somewhere and the carbon would be washed off the fire ring.

[Chili]

There are some closed loop systems, basically, the engine portion has a separate system that uses antifreeze. There is still an impellar or sea pump that circulates sea water to a heat exchanger to keep the engine coolant at bay. It's basically a liquid to liquid heat exchanger. The advantage would be the lack of salt/rust/minerals from the sea/lake water damaging the cooling system internals of the motor.

Gotcha!

[kpc01]

well finally had to yank the engine out. it did have a crack in the block that was just really hard to spot. heads/manifolds and everything else look perfect. I'll be dropping it all off at the machine shop tomorrow to see what I can find out. bad news is they say its getting harder to find a good std bore 5.7 block so will probably have to go .30 over

[kpc01]

this one uses raw water from the lake. the previous owner failed to remove the plugs from the block before the winter and evidently it got cold enough to freeze. seems like there aren't many that are closed loop systems, atleast not that i've seen.

[crapstang]

this one uses raw water from the lake. the previous owner failed to remove the plugs from the block before the winter and evidently it got cold enough to freeze. seems like there aren't many that are closed loop systems, atleast not that i've seen.

That's an all too common mistake made by boat owners. Spend the little bit of time and care for it! Basic maintenance and protection goes a long way.

[kpc01]

That's an all too common mistake made by boat owners. Spend the little bit of time and care for it! Basic maintenance and protection goes a long way.

tell me about it. drives me crazy when people have nice things and let them ruin or don't care for them. Of course I wouldn't of gotten a deal on this boat so I guess its my gain. This was close to a 50k boat new and they let it sit and a lot of stuff ruined. Boats seem to be the worst thing for this but I hate any nice things going to ruin

[Rreemo]

this one uses raw water from the lake. the previous owner failed to remove the plugs from the block before the winter and evidently it got cold enough to freeze. seems like there aren't many that are closed loop systems, atleast not that i've seen.

Yeah, the closed systems aren't very common until you get up into the higher end boats...typically those that float in salt water. It is more crap to deal with, but also much easier to winterize one that's closed with coolant on the engine side.

What you are dealing with is such a common issue too....there are a ton of people that either don't know that they need to winterize or just instead take the chance b/c they are in dry storage or something. Either way, it's not all that hard...instead of trying to entirely drain it, I used to just drain my manifolds and then pull the upper hose and add a gallon of coolant...then turn it over a little just until I saw that it was coming out the outdrive.