Water in the cylinders 4.3

[Tlray]

Hi all, Newbie to the group. I need some brain power sent my way. I have a 1998 19' Stingray boat with a 4.3 Thunderbolt Mercruiser.
I pulled the drain plugs in the fall and turned it over to make sure there was no water left in the engine. I took it to the lake for the first time this year last week. I started it before I left my driveway, it acted like it was flooded but it came around, I figured old gas, although I always use Stabil.
Launched the boat, fired right up. I took off and it sputtered a couple times and then took off running great. Went to an island on the lake and it died as I pulled ashore. I took the distributor cap off and it had a lot of moisture in it. Dried it out and cleaned it and it fired right up. Took off down the lake (towards the ramp) I ain't no dummy. Pulled into a cove under low rpm and it died, tried to start it and the starter went out.
So I get the starter rebuilt and put it in, it won't turn over. I have built a few Chevy V8s from scratch. When an engine won't turn over there are only a few things causing it. I pulled the plugs and water in both banks. I know the chance of Both head gaskets blowing out is highly unlikely. A cracked block into both banks of cylinders?
Is there any way the intake manifold gasket can leak into both banks?
I am sorry about this being so long, but I figure the more info I give you the better chance of you being able to help me. Thanks in advance.

 

[PAR]

Welcome the the forum.

You're listing a few different symptoms, which can be caused by a few different things. You starter issues shouldn't be related to moisture in the crankcase. Have you changed the oil and what was it's condition? It's likely you killed the starter just by trying to repeatedly start it and you should know if this was the case. They are designed to pull a heavy load, then cool, not to pull heavy load after heavy load. Now they can do many cycles on a hard to start engine, but after a while, they get hot and crap the bed.

You pulled the plugs (all of them) and found water in 2 or more cylinders? Which cylinders, how much water? As a rule, there's a set of procedures we run through to access an engine. might I recommend you purchase a manual for your engine drive combination and go through the typical procedures found in the very beginning of the book. Yeah, a lot of it you've likely done, but it will systematically help you focus down on what's really happening.

I've found most 2 decade old engine/drive packages need some serious maintenance issues addressed, if not very well cared for. Most will care for their boat while they're using it, but after some time, it gets used less and less, so it sees regular maintenance less and less. How many hours on this engine and a honest reply, to how it's been cared for in the last 20 years.

 

[Owly]

Hi all, Newbie to the group. I need some brain power sent my way. I have a 1998 19' Stingray boat with a 4.3 Thunderbolt Mercruiser.
I pulled the drain plugs in the fall and turned it over to make sure there was no water left in the engine. I took it to the lake for the first time this year last week. I started it before I left my driveway, it acted like it was flooded but it came around, I figured old gas, although I always use Stabil.
Launched the boat, fired right up. I took off and it sputtered a couple times and then took off running great. Went to an island on the lake and it died as I pulled ashore. I took the distributor cap off and it had a lot of moisture in it. Dried it out and cleaned it and it fired right up. Took off down the lake (towards the ramp) I ain't no dummy. Pulled into a cove under low rpm and it died, tried to start it and the starter went out.
So I get the starter rebuilt and put it in, it won't turn over. I have built a few Chevy V8s from scratch. When an engine won't turn over there are only a few things causing it. I pulled the plugs and water in both banks. I know the chance of Both head gaskets blowing out is highly unlikely. A cracked block into both banks of cylinders?
Is there any way the intake manifold gasket can leak into both banks?
I am sorry about this being so long, but I figure the more info I give you the better chance of you being able to help me. Thanks in advance.

The intake on a V engine has a water crossover normally, but the probability of this rusting through and leaking both ways into only two cylinders is extremely low. Most likely you have a cracked block IMHO. I don't know what your block draining procedure is, but if multiple drains are joined to a single drain point, it is fairly easy for the small block drain openings to end up plugged, and the water you are seeing drain out is coming from higher up in the engine. I would never run an inboard or IO without having a way to drain the two drain plugs low down in the block, and actually see them drain. personally I would not run a raw water cooling system on anything... period!
Take the valve covers off, and loosen rockers. Then take a spark plug, and knock the ceramic out of it, and weld it to pipe fitting so you can screw on an air fitting. Pull the plugs, and put line pressure compressed air in each of the two problem cylinders. You will hear air leaking around the rings and down through the crankcase, and perhaps some seeping past valves, but there should be absolutely none in the water jacket. Knock soft plugs out of the block adjacent to the two problem cylinders, and listen there. You are going to have to pull the engine in any case.

Also of concern is the fact that you tried to turn the engine over and it wouldn't........ did it turn over a little way and stop, or just not move? If it turned over and stopped, you have probably bent a rod at the very least, I've also seen them crack blocks through the main saddle, and bend crankshafts......... I would personally say that you most likely have big trouble, and will end up buying an engine. A salvage yard engine that runs good, is a good bet, but keep in mind that there are more than one version of the 4.3, and not everything interchanges. I know this from experience.
You probably don't even have a "core engine", and if you buy a rebuilt, they will charge you for a core.....

H.W.

 

[Tlray]

I don't have any water in the oil and I drained the lowest drains on the block. The two front cylinders on each side had more water than the back ones,

 

[Tlray]

The intake on a V engine has a water crossover normally, but the probability of this rusting through and leaking both ways into only two cylinders is extremely low. Most likely you have a cracked block IMHO. I don't know what your block draining procedure is, but if multiple drains are joined to a single drain point, it is fairly easy for the small block drain openings to end up plugged, and the water you are seeing drain out is coming from higher up in the engine. I would never run an inboard or IO without having a way to drain the two drain plugs low down in the block, and actually see them drain. personally I would not run a raw water cooling system on anything... period!
Take the valve covers off, and loosen rockers. Then take a spark plug, and knock the ceramic out of it, and weld it to pipe fitting so you can screw on an air fitting. Pull the plugs, and put line pressure compressed air in each of the two problem cylinders. You will hear air leaking around the rings and down through the crankcase, and perhaps some seeping past valves, but there should be absolutely none in the water jacket. Knock soft plugs out of the block adjacent to the two problem cylinders, and listen there. You are going to have to pull the engine in any case.

Also of concern is the fact that you tried to turn the engine over and it wouldn't........ did it turn over a little way and stop, or just not move? If it turned over and stopped, you have probably bent a rod at the very least, I've also seen them crack blocks through the main saddle, and bend crankshafts......... I would personally say that you most likely have big trouble, and will end up buying an engine. A salvage yard engine that runs good, is a good bet, but keep in mind that there are more than one version of the 4.3, and not everything interchanges. I know this from experience.
You probably don't even have a "core engine", and if you buy a rebuilt, they will charge you for a core.....

H.W.

After surfing the net I came up with this, Apparently, when I drained the engine last fall I failed to drain the exhaust manifolds. I know, Duh. So if the manifolds are cracked from freezing would that let water into the cylinders?

 

[Tlray]

The engine has less than 400 hours on it. This my second year of owning it. And yes I'm sure I burnt the starter up while trying to start it. I have come across another scenario: While draining the engine last fall I failed to drain the exhaust manifolds, is it possible that the manifolds froze and cracked causing this problem?

 

[Owly]

After surfing the net I came up with this, Apparently, when I drained the engine last fall I failed to drain the exhaust manifolds. I know, Duh. So if the manifolds are cracked from freezing would that let water into the cylinders?

If the water can run into the exhaust ports on the head, it will flow into any cylinders that have open valves............ I see this on stationary engines that live outdoors frequently. The bearings on the little flapper on top of the exhaust stack will wear out, and it will hang open, allowing rain and snow to find it's way into the exhaust manifold, and into any open valves, often resulting in a stuck engine. I've had to free up a number of engines that have rusted up this way.

H.W.

 

[fallguy]

oil the tops of the cylinders overnite and try to turn the engine by hand

No go, pull it. Probably bent some rods.

Bottom end likely coming.

I doubt you cracked the block by leaving water in the e.m.

 

[PAR]

Pull the plugs, vacuum out the cylinders and try to turn by hand, slowly. If it was me, I'd just skip all the analyse and pull the engine, knowing it's going to need some parts if not a replacement.

 

[Tlray]

Ok, I pulled the exhaust manifolds and did not see any cracks in either one. But I did find that both Shutter valves are gone. The rod that once held them is there but nothing else. Could this be the problem?

 

[fallguy]

The valves probably got sucked into the pump impellers.

Pull it all apart and see if you can turn the crank.

 

[PAR]

Since you've removed the manifolds, you've removed about 15% - 20% of the engines weight, maybe more, consider yanking it the rest of the way, as it's becoming more likely it'll need to come out anyway.

The 4.3, tied to an Alpha is a pretty easy engine pull, pickup a manual and alignment shaft and have at it. It's not hard, though you'll need an engine crane (which you can make from a few 2x6's and a come-a-long). Alignment can be tedious, but it's doable for the average guy, that's done major repairs on an engine before.

 

[Tlray]

The valves probably got sucked into the pump impellers.

Pull it all apart and see if you can turn the crank.

It turns over fine with the plugs out. I don't think I mentioned, the water temperature never went higher than normal. The person that had it before me put a new lower end on it. I wonder if it was because the valves going through it.

 

[fallguy]

It turns over fine with the plugs out. I don't think I mentioned, the water temperature never went higher than normal. The person that had it before me put a new lower end on it. I wonder if it was because the valves going through it.

Could be or they could still be in the exhaust if they just fell out.

If you are turning over; I'd replace the valves and give it a go after running some gas/oil on top no plug.

If the valves were missing; even a good dunk at the landing could have sent water in or just when you came up to the island the wake following.

The bigger question is did you damage the engine with water in it.

Maybe you got lucky.

 

[Tlray]

Could be or they could still be in the exhaust if they just fell out.

If you are turning over; I'd replace the valves and give it a go after running some gas/oil on top no plug.

If the valves were missing; even a good dunk at the landing could have sent water in or just when you came up to the island the wake following.

The bigger question is did you damage the engine with water in it.

Maybe you got lucky.

That would be nice. Doing a compression check tomorrow. I filled the exhaust with water today, no leaks.