water in engine oil, cracked port exhaust manifold and engine water jacket

[NHGuy]

I went for a little ride today. When I stopped to check my oil I found water in the engine oil.
Upon inspection I found a cracked ex manifold on the port side, it's on the outside. Goes along above where the center bolts are.
Does the water get in the crankcase through the combustion chambers and then past the rings? Or do I have another issue too?

 

[Bondo]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

I went for a little ride today. When I stopped to check my oil I found water in the engine oil.
Upon inspection I found a cracked ex manifold on the port side, it's on the outside. Goes along above where the center bolts are.
Does the water get in the crankcase through the combustion chambers and then past the rings? Or do I have another issue too?

Ayuh,... That be My guess,.... Is this the 1st run of yer season,..??

 

[NHGuy]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

No, that's why I am asking. I have run it 10 times at least. I did have a hydrolock in #5 & 7 (the rear port side holes), that was the 2nd or 3rd week out & changed a bad elbow to exhaust gasket then. I didn't notice the manifold that day. The gasket looked so bad that I thought I had the solution. I have used the boat a number of times since then.
And to complete my disclosure I warmed it and ran it all the way to wide open throttle today before the oil check showed water in the crankcase. I rarely get to full rpms but I try to do it once in a while.
I pulled those plugs this afternoon and they were good, no fouling and no water present.

 

[NHGuy]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

I'm feeling like I want to put on manifolds, repeatedly change the oil til it's clear and see what I get. Is that a dumb approach?
I have only owned this boat 4 years so I can't tell you whether it was in the ocean, but the drive isn't corroded as I'd expect a salt water drive to be.

Maybe running it hard blew through the exhaust jacket...? I had it spinning 4600 for a couple of minutes.

 

[NHGuy]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

move it up=bump me
Really hoping to hear input from some of you. I live by i-boats, there are good folks on here.
A guy on OSO thought I have a shot at being OK, but I'm still a little leery. His thinking was basically give it a try, small blocks can handle some of this stuff. I did put on new OE manifolds today but I ran out of light before I could get the oil changed. I sure hope it's all good.
Is the intake manifold gasket the same as a car or truck motor? I'm fresh water only.

 

[Bt Doctur]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

use one piece header gaskets . to install them (If you have the room) get 2 pieces of threaded rod ,studs, or long bolts with the heads cut off.
using cutting pliers, notch the end holes to slip over the bolts.
install 2 guide studs in the end holes of engine and slide manifold on. drop gasket in place over the 2 guide studs.
install 2 center bolts ,remove guide studs and install end bolts.torque to specs

 

[NHGuy]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

I wish I thought to notch the gaskets. I hung em on headless bolts, slid the manifolds on the bolts, started 2 real bolts, removed the beheaded ones & installed the last 2 bolts. I like seeing the Merc logo on the exhaust, OE for $20 more than that offshore copycat stuff is OK with me. It instills a little more confidence. And maybe there's some foundry worker in the USA that gets to keep working.

 

[Bt Doctur]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

unless i have the engine on a stand and rotated I`ve mangled way too many gaskets fighting with the manifold, not enough room to work,
a new gasket and installing bolts.this way the manifold is installed loose enough to slip the gasket in and install the bolts.no worrying about it slipping thru your fingers and breaking the gasket or worse.
This applies to big blocks only, the manifold gasket WILL FIT both ways ,only one way is correct.

 

[tpenfield]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

If you have a cracked manifold, then you may have a crack elsewhere in the engine.

This could be an insufficient winterization issue?

 

[NHGuy]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

tpenfield, that's my worry. So if it keeps gaining water I will look in the common water freeze spots.
But what's weird is I ran it a number or times this year, the problem didn't happen til the first week of August.
BTW sorry to hear of your motor, that stinks. And I think I saw that you may have found another boat?
Also question. On your big block you said the cooling system failed in the head, is that right? Did you say water went in the combustion chambers through the valve guides? I thought the water jacket wouldn't fail there, but what do I know, I don't build 'em, I just break 'em.
I haven't done enough learning to understand how that can be.
Were the head gaskets OK? On car & truck motors they are the suspect when there's coolant in the combustion chambers.
I am about to go do my oil changes if I can just prime my junky hand oil pump.

 

[tpenfield]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

NH:

Yes, my engine ran fine for the first few outings of the season. Then all hell broke loose and it destroyed itself in a single outing. If you have a crack in the block or head, it could be getting worse with use, to a point where it becomes a problem.

In hind sight, on my boat, if I had done a pressure test of the cooling system, I may have found that the valve guides were leaking. Knowing that ahead of time could have saved the day. As it was, the last ride in my boat was about a $6,000 ride. . .

So, my advice is to find out what is wrong before the engine decides to show you in no uncertain terms.

I'm still working on getting another boat . . .

 

[NHGuy]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

So, not surprisingly, the motor does have an internal problem. If I run easy, say 2500 rpm, it's fine, and does not get water in the oil. If I get on it, the water gets in.
So I will be pulling off the intake and heads as a start.
I will report what happens.

 

[HT32BSX115]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

So, not surprisingly, the motor does have an internal problem. If I run easy, say 2500 rpm, it's fine, and does not get water in the oil. If I get on it, the water gets in.
So I will be pulling off the intake and heads as a start.
I will report what happens.

If you're getting water into the engine internally, do not remove the heads until you pressure check the entire cooling system FIRST.

After removing the heads you cannot pressure check anything.

If a pressure check reveals a leak, you will want to know where that leak is. If it's a block leak, you'll be wasting your time removing and replacing otherwise serviceable heads, installing new manifolds etc......

 

[NHGuy]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

So I get that, would I be out of line pulling the intake to look in the valley? I have already unbolted the intake but it's still sealed. In fact I came on the forum today to ask how to free it from the heads & engine. It is stuck on well. I've put a screwdriver in at two corners but the manifold is resolute. I have removed the perimeter bolts, distributor, t-stat housing, coil, and whatever seems to be between the engine and the intake. I have left the carb on the manifold.
After I pressure test the cooling system, what's next, to get the intake off?
I'll go work on the pressure test now. I'm home on "vacation" this week. Is there a pressure test method in the stickies? I'm going there for a look.
Thanks for the heads up.

 

[HT32BSX115]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

I'll go work on the pressure test now. I'm home on "vacation" this week. Is there a pressure test method in the stickies? I'm going there for a look.

I think so........ but think of the engine as an air tank with several openings..........

After you remove the exhaust manifolds, close off all the openings using whatever plumbing fittings and hoses you can scrounge from Home Depot etc..... except 2.

Connect an (0-30psi) air pressure gage to one of them and a valve to the other with a quick disconnect on it (to connect to your air compressor)

Pressurize the engine to 15 or so PSI, close the valve and shut off the air compressor (so you can hear air leaks.!)

Assuming you closed off all the openings any leaks will be where water can also leak. If you have cracks on the outside of the block and cannot see them you can use soapy water to look for bubbles. If they're internal, you will hear them in the oil-fill tube. If a head gasket leaks, you might hear them with spark plugs removed etc etc etc.....

The engine should hold 15-20 PSI for quite some time if there's no leaks.....you might even see a leak at the water pump.....

 

[NHGuy]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

So, there is an air leak, comes up the carb. I still don't see how to free the intake from the motor. I'm going out to the boat to figger it out...

 

[HT32BSX115]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

So, there is an air leak, comes up the carb. I still don't see how to free the intake from the motor. I'm going out to the boat to figger it out...

An Air leak in the "carb" can be several things. Intake manifold leak ( gasket, crack) , head crack, (or with an open intake valve, a head gasket)

You're getting closer!

I still don't see how to free the intake from the motor.

once you get all the bolts removed, it's just held on by gasket "glue"

If you don't find a block leak because of other leaks, I would still suspect the block until I PROVED it to be "leakless"!!

 

[tpenfield]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

You could remove the manifold and block the water ports to the heads and then do another pressure test. .

Or . . If you can snake a listening device down the intake manifold to try to isolate the noise/leak

It still could be a leak in the intake side of the head, as that would come up the intake.

 

[NHGuy]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

So I must have halfazzed my winterization & just not run it hard til now. There was a crack in the valley, same side as the cracked exhaust manifold.
I thought about using the lock n stitch system for a repair, but it's the middle of the season and they are all the way in California.
I did a marine tex repair, which is supposed to cure over night. I will retest the cooling system with air pressure when the cure time is up.
The air noise coming from the intake has me wondering if there is a head gasket or valve issue. If not I was just hearing the air squirting up toward the intake manifold, that's the direction the crack is pointed. Now that I have the stuff it will really be a very quick test.
For anyone wanting to know how the cooling system can be easily pressure tested. Here's my suggestion.
I went to the cheap tool place, you know, everything is a copy of real stuff. But it's cheap. They have packaged line clamps and I needed to clamp off 4 lines. So 2 packs are enough to get my sizes and quantities. I have a V8 engine so there are 2 elbows and 2 manifolds, V6's are similar. I clamped off the incoming line from the transom via the power steering cooler, also clamped off both exhaust manifold lines and one riser line. I took a cheap chisel handle that matched the inside diameter of the other riser hose. Cut it about an inch long, drilled a hole down the middle and stuck the valve from a bicycle tube in there with a skirt of tube material around the outside of the plug. Then all I had to do was push the valve & handle rig into the end of the hose and clamp it off. Now I can air up the cooling system to test as needed. I spent $20 on clamps and ruined 1/3 of a $5 set of cheap chisels.

 

[HT32BSX115]

Re: water in engine oil, cracked port exhaust manifold

Re: water in engine oil, cracked port exhaust manifold

I did a marine tex repair, which is supposed to cure over night. I will retest the cooling system with air pressure when the cure time is up.

Good luck on that. While it might work temporarily on the outside, the cast iron is usually impregnated with oil on the inside and epoxy doesn't like to stick.

I'd start looking for a wrecking yard 350 out of a pickup.