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Mercruiser 3.0 water in oil and leak from manifold area

A

Alex4

New member
Recently bought a 96 searay I/O thing runs great starts up smooth, idles smooth. But checked oil and noticed a slight amount of milk look to it. Previous owner said it hadn’t been changed in maybe a year. Also noticed a good amount of water leaking out from under the manifold somewhere just above the freeze plug. Anyone have any experience with this happening and the outcome other then a cracked block?

hoping it’s just a crack in the manifold but not sure if that would lead to some water being in the oil??
 
bondo said:
Ayuh,....... You bought a frozen junk motor,......
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Not much of a chance it’s just a bad gasket or the manifold is cracked? Plan to take it apart and pull the manifold then hope for the best I’ve been told could be both cracked block and manifold or either or. Drained oil today and ran it, planned to change again and filter then watch for any more tan/milky colored oil. Is that a little far fetched to think just the manifold could be my main issue with no internal block cracking?
Leaks maybe 12oz of water down the block every minute so it’s pissing pretty good
 
99 percent bad block 1 percent manifold. Sorry. Either way you got taken. Might as well run it with cracked block until it blows up...might get half hour or so out of it before the babbit gets eaten off the bearings and it locks up. Start looking for new boat, that one isn't worth repower.
Next time you go shopping buy a boat with a clean recent survey.
 
Oil in water is a bad sign. Block or heads are cracked. I'm sure you bought a lemon. I would repower the boat if it's in good shape.
 
This is my thought,

Change the oil and filter, you may need to do this a couple times to get any residual moisture out (if there is no crack internal).

remove the manifold, (get new gasket when reinstalling)

Find crack on the side of the block (water jacket), it will be easy to see, get a dremmel tool or similar grinding tool and lightly grind away about 1 inch on each side of crack to clean paint and any rust away from surface. The water jacket exploded outward from freezing.

Get some J&B weld two part epoxy and mix it, smear it across the exposed area covering the crack and the exposed metal surface on each side. (try not to get any inside the crack or block, it is a water passage).

You may want to do it twice. Let each dry for at least 24 hrs til fully hardened. Do not get any on gasket surface!!

Check manifold also as it also cracks on the bottom which you cannot really see until you remove and flip it over. Be prepared to repair or replace manifold. This cannot be as easily JB welded but if not bad you can get away with it.

I have done several and have seen many 4 cylinder engine blocks repaired this way and run for many many years with no issues.



Just remember if the oil once replaced a couple times continues to get milky,your done!

Most 4 cylinders believe it or not dont crack internal, it is usually exactly what you have (at the moment). If this were a V6 or V8 and milky oil that would be the end. They almost always crack inside the block and CANNOT be repaired.

Let us know what you do and if any "repairs" works
 
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Your better off to remove the engine. Dis assemble it and take it to a machine shop. Let them determine what needs to be changed. Otherwise you may spend a lot of time and money for nothing.
 
A machine shop wont touch it.........unable to warranty it.

Even though I would not normally recommend a "backyard" fix such as this.

This is very typical for this specific engine.

As I said I have done many and seen many more done this way..........

No expense other than elbow grease and a manifold gasket, JB weld.
 
I meant have the machine shop check the block for cracks. And the manifold and the head.. they'll be able to tell you if and where it's cracked.
 
Based on my experience I would suggest doing it my way first.
He said it runs good with the exception of the obvious leaking.

The water could be getting in by way of a internal cracked in the Exhaust manifold, so as i suggested that may need to be replaced. That could e easily brought to a shop and pressure checked to be sure,

The inline 4 rarely cracks inside the block, I have never seen one myself.

The heads are also rare to crack due to freezing, Not unheard of but rare. I have not this due to freezing, usually due to over heating

To bring it to a machine shop now would run into a fair amount of $$$$...........

in the end it is up to him which path he follows.
 
While you probably won't die in a ball of flame if the engine konks out like you would if you were in an airplane...having a rock solid reliable engine is a safety issue. Not just for you but your passengers/guests. You don't want to be drifting helplessly for ANY length of time if my wife is aboard. Anyway, while Jack's repair may work I personally wouldn't be comfortable resting my entire cruise on it's ability to hold. If you're on a small lake it's probably not a thing, but if you're miles from shore it can make for a miserable day.
 
o2batsea said:
While you probably won't die in a ball of flame if the engine konks out like you would if you were in an airplane...having a rock solid reliable engine is a safety issue. Not just for you but your passengers/guests. You don't want to be drifting helplessly for ANY length of time if my wife is aboard. Anyway, while Jack's repair may work I personally wouldn't be comfortable resting my entire cruise on it's ability to hold. If you're on a small lake it's probably not a thing, but if you're miles from shore it can make for a miserable day.
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I could not agree more!
JB Weld and/or epoxy repairs are intended to be used for the home stuff!

My grandfather typically said: "if you do not have the time to make a proper repair now..... when will you find the time to make it later?" ;)
 
RicardoMarine said:
I could not agree more!
JB Weld and/or epoxy repairs are intended to be used for the home stuff!

My grandfather typically said: "if you do not have the time to make a proper repair now..... when will you find the time to make it later?" ;)
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Who cares if you agree. What do you know. This is a Mercruiser not a Swedish fish.............................Stay away!

This is not a safety issue such as a fire hazard or a loss of steering. It is a water jacket external crack. It is a leaking water issue to start, if his bilge pump works that should mitigate most if not all of the risk.

If he follows my advice and the only real issue for leaking water into the boat is the crack at the water jacket he will be fine and have many many years of use with a JB weld fix.

All other issues, if found will need a different approach.

Also this boat will most likely be used on a fresh water lake or pond. It most likely WONT be used in the ocean.
 
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Honestly I have done far worse things than gum up a crack with JB Weld to keep the wheels on. As long as you know it's like that and don't try to sell anybody the boat and not tell them....
What's that they say...nothing is as permanent as a temporary fix?

It's people who cover a rusted out chassis with bondo and black paint that you gotta look out for....
 
kghost said:
Who cares if you agree. What do you know. This is a Mercruiser not a Swedish fish.............................Stay away!

This is not a safety issue such as a fire hazard or a loss of steering. It is a water jacket external crack. It is a leaking water issue to start, if his bilge pump works that should mitigate most if not all of the risk.

If he follows my advice and the only real issue for leaking water into the boat is the crack at the water jacket he will be fine and have many many years of use with a JB weld fix.

All other issues, if found will need a different approach.

Also this boat will most likely be used on a fresh water lake or pond. It most likely WONT be used in the ocean.
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I too have this same crack located just below the head about 7 inches in length. I do have water in my oil however given this is most likely a water jacket crack I suspect the water got in another way perhaps through the exhaust elbow and the water flapper was junk. I'm going to patch this crack with jb weld and I have a spare manifold, elbow and head I know are good so if I get water entering after these things then I'm going to just use it at least for the summer and do very frequent oil changes and save up for a better boat. However if no more oil then I'll keep using it as I've read that jb weld fix given its not a sealed system is a pretty sure fix. I used jb weld on my ac condenser on my car and it's held up under pressure now for three years now issues.
 
I'm going to report back in a few days after I jb weld that crack, replace the head, manifold, elbow, flapper and all the gaskets and hope to have good news for anyone else else that has similar concerns. Stay tuned
 
Alex4 said:
Recently bought a 96 searay I/O thing runs great starts up smooth, idles smooth. But checked oil and noticed a slight amount of milk look to it. Previous owner said it hadn’t been changed in maybe a year. Also noticed a good amount of water leaking out from under the manifold somewhere just above the freeze plug. Anyone have any experience with this happening and the outcome other then a cracked block?

hoping it’s just a crack in the manifold but not sure if that would lead to some water being in the oil??
Click to expand...
To my understanding this is where these all crack and are most likely external. Doing a good job prepping the crack and drilling a hole on each side of the crack to prevent spreading seems to work for most with jb weld. Most here will tell you if there's water in the oil then it's probably an internal crack but that's not always the case. Water could be coming from a worn exhaust elbow gasket, corroded risers or elbows at the water jackets, bad water flapper or a cracked manifold or head. I'd patch that crack, check your manifold elbow gaskets, head gaskets and head, change the oil and give it a whirl before immediately assuming the crack is internal. These are much easier faster solutions to try first. If it's still seaping water into the oil then you'll have no choice but to swap motors.
Alex4 said:
Recently bought a 96 searay I/O thing runs great starts up smooth, idles smooth. But checked oil and noticed a slight amount of milk look to it. Previous owner said it hadn’t been changed in maybe a year. Also noticed a good amount of water leaking out from under the manifold somewhere just above the freeze plug. Anyone have any experience with this happening and the outcome other then a cracked block?

hoping it’s just a crack in the manifold but not sure if that would lead to some water being in the oil??
Click to expand...
 
daniel.stoltz said:
To my understanding this is where these all crack and are most likely external. Doing a good job prepping the crack and drilling a hole on each side of the crack to prevent spreading seems to work for most with jb weld. Most here will tell you if there's water in the oil then it's probably an internal crack but that's not always the case. Water could be coming from a worn exhaust elbow gasket, corroded risers or elbows at the water jackets, bad water flapper or a cracked manifold or head. I'd patch that crack, check your manifold elbow gaskets, head gaskets and head, change the oil and give it a whirl before immediately assuming the crack is internal. These are much easier faster solutions to try first. If it's still seaping water into the oil then you'll have no choice but to swap motors.
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A crack in the manifold would 100% cause water in the oil. The intake valves would suck in water that's leaking into the exhaust. Check the exhaust riser gaskets and inspect the elbow also to make sure water isn't going past the gasket into the exhaust
 
daniel.stoltz said:
I too have this same crack located just below the head about 7 inches in length. I do have water in my oil however given this is most likely a water jacket crack I suspect the water got in another way perhaps through the exhaust elbow and the water flapper was junk. I'm going to patch this crack with jb weld and I have a spare manifold, elbow and head I know are good so if I get water entering after these things then I'm going to just use it at least for the summer and do very frequent oil changes and save up for a better boat. However if no more oil then I'll keep using it as I've read that jb weld fix given its not a sealed system is a pretty sure fix. I used jb weld on my ac condenser on my car and it's held up under pressure now for three years now issues.
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you may want to pressurize the block with compressed air and see if you get air coming out the crank case before doing all that work. At least this way if the block is internally cracked you wont waste time swapping stuff.
 
daniel.stoltz said:
I'm going to report back in a few days after I jb weld that crack, replace the head, manifold, elbow, flapper and all the gaskets and hope to have good news for anyone else else that has similar concerns. Stay tuned
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Update on water in oil and cracked block. Jb weld on the block worked fantastically! Turns out the oil in the water was a blown head gasket. It was very visible. After jb weld, new head, intake gasket, exhaust elbow gasket, flapper, thermostat, and oil change I took her out and not a drop of water leaking from the block and the oil was so clean I could barely read it. Total cost for parts and materials was about 200 bucks and 8 total hours of my time.
 
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