Water in my new 5.7 engine

[mot]

I just put a new GM 5.7 engine in my 25 wellcraft coastal. New Osco manifolds & risers. After running great all season I was sitting at a high idle getting ready to head out and the engine stalled out. I brought it home a week later to discover water in the cylinders & crank case. Taking the elbows off the gaskets looked ok. I need some info of what could have gone wrong. thx

 

[Bt Doctur]

Re: Water in my new 5.7 engine

remove the thermostat housing and see if the intake manifold has a rotted hole.

 

[alldodge]

Re: Water in my new 5.7 engine

:welcome: to iboats

When you were sitting at high idle what was the situation with the load on the boat? Were there waves coming in, was there excessive load on the stern of the boat (folks sitting on the stern)? Any thing else's about what took place prior to the stalling?

 

[tpenfield]

Re: Water in my new 5.7 engine

Is the engine 'new' or a rebuild/reman ???

 

[mot]

Re: Water in my new 5.7 engine

Engine was new GM from 1800 runs new. New intake I was washing the boat but I cant see how that water could get into the engine. I was on a mooring so there wasn't a lot of waves hitting the stern. I had replaced the exhaust flappers a few years ago and when I took the risers off they seem to be working fine

 

[alldodge]

Re: Water in my new 5.7 engine

Was wondering if it had enough weight on the stern to put the risers below the water line, guss that didn't happen. I would suggest doing a compression test next.

 

[Silly Seville]

Re: Water in my new 5.7 engine

I just put a new GM 5.7 engine in my 25 wellcraft coastal. New Osco manifolds & risers. After running great all season I was sitting at a high idle getting ready to head out and the engine stalled out. I brought it home a week later to discover water in the cylinders & crank case. Taking the elbows off the gaskets looked ok. I need some info of what could have gone wrong. thx

Nowhere near enough info to begin a diagnosis...just guesswork at this point. To the OP, what is your location? This could be freeze damage allowing water into crankcase. You say "just put in the engine" yet you say "ran great all season. Which is it? How long has the new engine been in service (hours of use)? Are you in saltwater? Is this a marine engine or something you ordered from the Summit catalog? Did you install the engine or a professional shop/dealership/marina? We need a lot more specific info. For example, do you know for a fact there was water in the engine on the day the engine stalled out? Did you try to diagnose the no-run condition the day it happened, or did you leave the boat sitting alone in that condition until the next week? What were the weather conditions in your marina in the days preceding the no-run condition? What was the weather doing the week the boat sat alone. Are you in a covered slip? Is the engine raw or freshwater cooled? Do others have access to your boat?

 

[spdracr39]

Re: Water in my new 5.7 engine

Defective head/head gasket or improper torque on the head bolts possibly but as stated above we are only guessing. Definitely need a compression test to start things off.

 

[mot]

Re: Water in my new 5.7 engine

Thanks for all the posts. This is my first time posting on a forum and I should have been more specific. Here goes. I keep my boat at a mooring in Plymouth Harbor Mass. I replaced the 5.7 engine in the fall of 2012 with the help of a automobile mechanic. New gm long block we put on new Osco manifolds & risers.Broke in the engine for apx 25 hours (ran great) and had the Marina winterize it. In the spring of 2013 I had the marina service it and get it ready for the season. It ran great all season. Just had to tighten up the belts and add fuel. At the end of the season I was going to head out fishing. I started the engine with no problem, ran great. I was sitting at the mooring for about 10 to 15 minutes at about 1500 RPM washing down the boat and it stalled out with no warning. I tried starting it again and It tried but wouldn't catch. Then every attempt acted like the battery was dead. I had had enough so the next day I brought my trailer and hauled it home. One week later I brought it to the Marina and in his attempt to winterize it he discovered a gallon of water in the crank case and water in all the cylinders. He drained it put fresh oil into it and some tranny fluid down the carburetor to protect the engine. The engine turns over fine. My friend and I took off the risers and the gaskets looked fine. We plan on pulling the engine out at some point. How far we need to go I don't know. Thanks again for any advise.

 

[alldodge]

Re: Water in my new 5.7 engine

Thanks for all the posts. This is my first time posting on a forum and I should have been more specific. Here goes. I keep my boat at a mooring in Plymouth Harbor Mass. I replaced the 5.7 engine in the fall of 2012 with the help of a automobile mechanic. New gm long block we put on new Osco manifolds & risers.Broke in the engine for apx 25 hours (ran great) and had the Marina winterize it. In the spring of 2013 I had the marina service it and get it ready for the season. It ran great all season. Just had to tighten up the belts and add fuel. At the end of the season I was going to head out fishing. I started the engine with no problem, ran great. I was sitting at the mooring for about 10 to 15 minutes at about 1500 RPM washing down the boat and it stalled out with no warning. I tried starting it again and It tried but wouldn't catch. Then every attempt acted like the battery was dead. I had had enough so the next day I brought my trailer and hauled it home. One week later I brought it to the Marina and in his attempt to winterize it he discovered a gallon of water in the crank case and water in all the cylinders. He drained it put fresh oil into it and some tranny fluid down the carburetor to protect the engine. The engine turns over fine. My friend and I took off the risers and the gaskets looked fine. We plan on pulling the engine out at some point. How far we need to go I don't know. Thanks again for any advise.

I'll still suggest a compression test before you pull it.

 

[84EdH]

Re: Water in my new 5.7 engine

mot, do a cylinder compression test and then test the engine block for leaks before you tear it dow. bummer, though, all that work and trouble within one year.

 

[thumpar]

Re: Water in my new 5.7 engine

What kind of motor did you get? Was it marine? If it had a hot cam there is a chance of reversion.

 

[mot]

Re: Water in my new 5.7 engine

I'm beyond disappointed. The engine was bought through 1800runsnew. New GM marine engine. I haven't had time to review the warranty info. My guess is that I'm on my own. It was a stock cam as far as I know.

 

[NHGuy]

Re: Water in my new 5.7 engine

What GM engine did you buy? Specifically do you know the cam lobe separation angle? If you bought a hypo car engine cam it could revert water at idle. That would explain the water in the cylinders.
Also check to see if the engine has an oil cooler, if it has a cooler that was kept over from the old motor that could be something to check. If it has corroded then it can put water in the motor oil. That would be quite a coincidence that both things happened.

The fact that the water is in the combustion chambers and in the motor oil really looks as if you have an intake manifold with the coolant passage that's rotted out.
You also should recheck the gaskets between the exhaust manifolds and the risers for signs of water tracks going toward the inside, I know you say they are ok, but be sure.

I agree on a compression test, also.

Might need to open it up for a look, stinks to need it so soon after replacing the motor.

 

[NHGuy]

Re: Water in my new 5.7 engine

nevermind, cam answer given above.

 

[Lou C]

Re: Water in my new 5.7 engine

Did the engine come with an intake or did the mechanic re-use the one from the old engine (used in salt?)
What about exhaust flappers?
I agree with checking the inside of the exhaust gas passage in the manifolds for water/rust tracks. However, that much water is unlikely to come only from the exhaust.
This is one reason why I feel all inboards should have closed cooling at least a half system, you don't have to worry about a rotted out engine.

 

[84EdH]

Re: Water in my new 5.7 engine

you should be able to find out in 10 minutes what engine is in your boat. I just looked at the website you listed above. call them up, ask to check there records. did you buy a stock marine 5.7 long block or a performance block? as asked above..did you buy a long block or did it come with intake manifolds etc. fill us in with the details and we can give better help.

 

[mot]

Re: Water in my new 5.7 engine

The engine was a stock marine pre vortec 5.7 roller cam. 12 bolt intake. I purchased a new intake & installed it. I contacted the company today and they suggest it was a matter of idling to long and the water not having enough pressure to push the water through the system, therefore it found a weak spot in the gasket between the elbow and manifold or the manifold & the head. They state that water in the engine always comes from the exhaust At least that's what I got out of the conversation. He suggests that if I don't get the engine heated up enough to heat up any water left in that engine it will be junk by spring. Any thoughts?

 

[84EdH]

Re: Water in my new 5.7 engine

as far as getting the water out of the engine he is absolutely right. you should have drained the block and changed the oil already. crank the engine, start it on muffs if possible, then drain oil and replace again. Especially with salt water. do it asap. at this point nobody knows where the water came from: exhaust manifold rusted through, gasket leaks, head gaskets, cracked block? its a mystery. a compression check of the cylinders will tell you if the head gaskets are intact. also, you can pressurize the block through the raw water feed hose with air, block off the hoses that go to the exhaust manifolds and see if the block holds air. if it does not, you have a failure in the block integrity somewhere. If the pressure tests hold up, you can take the manifolds off and check them for leaks, if they hold up, you can check to see if flappers still intact at the y pipe under the risers and maybe water was ingested at idle.

normal idle for 5.7 is around 700 rpm and water is pushed through the system no problem. so no way 1500rpm was a problem. notice that the two things the company suggested were possibly at fault were the manifolds, and elbows YOU installed.

I would be tempted to drain the block and oil, replace oil run/crank the engine, drain and replace again and then run the engine on muffs. if it was ingestion through the exhaust, you wont see any more water in the system on muffs. if you do get water again, you know its one of the things listed above.

if you don't get water in system on muffs, pull risers and check the flappers.

 

[NHGuy]

Re: Water in my new 5.7 engine

Running it all the way up to full warm for a good amount of time is smart, that will get any trapped moisture out of the engine. But how to do that if it's pulled for the season isn't easy. Without a load it won't make as much sustained drying heat as running it while pushing your boat.
You need to fix whatever allowed the water in first though.
Water in the combustion chambers usually does come from the exhaust, but how it got to the crankcase is a mystery. It doesn't go past the rings into the crankcase as far as I know. If it does someone who knows more than me will correct me.
During the boat season this summer did the oil look right? Any signs of milkshake oil? How many oil checks do you think you did? If the oil has been "growing" all summer maybe the marina didn't do the winterize correctly last year, causing a crack in the motor. Our blocks crack in the valley above the lifter bores under the intake if poorly drained. Then water gets in the oil when the motor runs. That's how I once got water in my oil.
Inspect the exhaust manifolds too, if they crack externally you will get water in the bilge. If they crack internally you get water in the combustion chambers. But the exhaust manifold to riser seal is the weakest spot and the most common fail point. If your risers and exhaust manifolds aren't of high enough quality there could be a poor surface for the gasket to seal. They can be machined flat if they aren't tight enough. Pray that the problem is there, it's a cheap fix.
Did you have to run the bilge pump more this summer than previously? That would be another manifold crack or riser gasket sign.
You can test the motor itself for cooling system cracks by sealing off the cooling exits and pressurizing the system, then listen for escaping air. Get some hose line clamps and seal off the water lines coming out of the motor going to the exhaust water jackets. Rig something to the incoming water feed to the thermostat inlet hose and pressurize it to about 15 psi.
To test the manifolds and risers there's a process in the stickies at the top of the forum. Basically you turn them upside down and fill them with acetone, which since it has smaller molecules than water, will find any cracks and escape more easily.
Bummer to deal with this just as it starts to get cold.
I'd help you personally if I had any time, I live just north of Boston, but work is nuts this time of year. I might be able to do something Thursday. I can also go into in even more detail if you want. PM me, for my phone number if you'd like.