Water in OIL!!

[magarmuch]

I bought a Volvo Penta powered boat in the winter, its a 5.0Gi coupled to an SX-M outdrive, year 1999. All systems checked out fine, started boat using ear muffs to warm the engine and change the oil before going out to the lake last weekend. I was surprised that oil was totally "milkshake" like, so I added new oil (did not change filter), ran the boat for another 5 min and again only milkshake came out. Today I removed inlet manifold and heads, lots of milkshake in the "V", but could not find any cracked in the block!! Cylinder head gaskets look fine with no sign of leakage between oil and water passages. Inlet manifold gasket look OK, did not see any obvious problem. I'm at a loss, where is the pr oblem? Any help or suggestions will be highly appreciated. Thank you.

 

[alldodge]

:welcome: to iboats

Do you have an engine oil cooler, not a power steering cooler?
If not my first guess is you have a cracked block. sucked the oil out of the pan and fill the block up with water to see if it shows back up

 

[bruceb58]

Before you took it all apart, you should have pressurized the cooling system. You have to put it all back together and do the pressure test now.

What part of the country did this boat live in?

 

[magarmuch]

I live in Virginia, boat was not running when I bought it due to an electrical fault which is fixed now (corroded ignition wire). The GM 305 motor does not show any external crack, dipstick oil was clean. Now that I have opened intake manifold I cannot see any crack in the "V" area either. Could there be a crack at the base of the cylinder such that the water enters the sump? All the freeze plugs look good, I only read about block cracking externally or in the V region, never read about cracking at the base of cylinder.

Boat does not have a oil cooler, only power steering cooler.

 

[bruceb58]

Crack could easily be internal. Won't know until you pressure test.

 

[magarmuch]

:welcome: to iboats

Do you have an engine oil cooler, not a power steering cooler?
If not my first guess is you have a cracked block. sucked the oil out of the pan and fill the block up with water to see if it shows back up

The oil is already out, so are you suggesting to I fill the engine with water? to what level? please explain with a few more words, I don't follow you. Thank you.

 

[bruceb58]

I sure hope he didn't mean water in the crankcase!

 

[alldodge]

The oil is already out, so are you suggesting to I fill the engine with water? to what level? please explain with a few more words, I don't follow you. Thank you.

No, water can be poured into the water jackets on the top of the block to fill the water jackets. If it has a very small internal crack it may not show up. If you can fill a side and the water goes down after a bit, it is leaking on that side

dipstick oil was clean

oil is lighter then water, so when the dip stick is pulled oil coats it because its on top the water

 

[magarmuch]

No, water can be poured into the water jackets on the top of the block to fill the water jackets. If it has a very small internal crack it may not show up. If you can fill a side and the water goes down after a bit, it is leaking on that side

OK, thanks for the clarifications, yesterday I plugged all the water passages and filled the block with water, happy to report no water leakage, water level remains constant overnight. This indicates the block does not have a crack. I checked the cylinder heads for warpage using a steel ruler, again: to the naked eye the heads look straight with no apparent crack, Any advise before I start putting everything back together? Thank you guys.

 

[Maclin]

That won't show much. You need to perform a cooling system pressure test, only way to be sure. Even then sometimes a crack will not open up until the engine is running and at temp and under some stress/load.

 

[alldodge]

OK, thanks for the clarifications, yesterday I plugged all the water passages and filled the block with water, happy to report no water leakage, water level remains constant overnight. This indicates the block does not have a crack. I checked the cylinder heads for warpage using a steel ruler, again: to the naked eye the heads look straight with no apparent crack, Any advise before I start putting everything back together? Thank you guys.

Still need to figure out where the water was coming in. As I mentioned above

If it has a very small internal crack it may not show up

Need to find out where the water came in from. It could be a crack that only shows up under pressure, or heat causes it to expand. In the pic above I see some rust on the block surface, also kind of looks like the rust made it over the cylinder. This surface should not have rust in that location. If you head gasket was leaking in that location then this could be the reason.

What do you think it looks like?

 

[magarmuch]

No Title

Here is a better picture of the left cylinder banks with the head gasket removed, I'm not an expert, I don't see any obvious sign of leakage.

 

[Maclin]

If it is a crack in the water jacket(s) then the top of the cylinders, i.e. pistons and valves, will not show problems. If it is water jacket leak the water goes right into the crankcase (oil pan).

 

[magarmuch]

Problem fixed I assembled the engine with new cylinder head and intake manifold gaskets. Pressurized the cooling system to 14psi and it held the pressure. I've taken the boat out three times and put about five hours on it and the oil remains clean. I could never figure out how and where the water had got into the engine. The cylinder head gaskets looked fine, the intake manifold gasket "looked" a little rough but no obvious sign. there is a chance some one deliberately put water into the engine with a hose. This is my first boat with a V8 with an I/O drive, My previous boat was a SeaDoo with a Mercury V6, 2 stroke, jet drive, I must admit I love the way the I/O handles and steers, especially at low speed. The smoothness of the V8 is relaxing. Above 3500rpm there is some vibration, but since I never owned a V8 boat before therefore I'm not sure if this is normal. Thank you all for your suggestions and comments

 

[alldodge]

Glad to hear you got the water issue fixed, and we all appreciate coming back and letting us all know what took place.

As for the vibration, it normally gets smoother with higher rpm. It could be something as simple as a plug not firing sufficiently or maybe compression a tad low on one cylinder. Just keep an eye on it and if you want to figure it out start with a compression and leak down test

 

[horseonthefly]

At least in my 3.0 the oil filter held enough water/oil mixture to milkshake the engine. Mine had a blown head gasket and the previous owner replaced the oil but not the filter making a milkshake. I picked it up for scrap value, replaced oil and filter (and basically everything he did) and the milkshake went away.

As for the vibration, is it underway or in neutral? If underway, how's your prop?

 

[AbelVar]

Let me start by saying OUCH! I am no mechanic but I have done a lot of work on the boats I have owned over the years. My first thought when I see water in my oil (happened more than once I am sorry to say) is that there may be a crack in the exhaust manifold. When it is a small crack water can seep into the engine through the intake or exhaust valves through the pistons into the crank case. When the engine is running there is no problem because of the positive pressure from the cylinders but when the engine sits not running the water can seep in. If it is a big crack it has been my experience the engine will not turn because of the water in the cylinder (s). The contaminated milky oil could still be there because you didn't change the oil filters. if you look inside your exhaust manifolds and see a lot of rust this may be something to consider.

 

[magarmuch]

Here is a link to the engine running for the first time after the new cylinder head and intake gaskets. As you can see its running really smooth. When under way it is also smooth and plenty of power, however there is that low frequency vibration which seems to be too low for the propeller. The propeller is in good condition, no dings or cavitation wear. I had the gimbal bearing replaced by a shop, the mechanic told me the alignment was good, however I did not check the alignment myself. All the motor mounts appear good also. The one thing I noticed is that the Harmonic Balancer seems to be out of roundness! This can be seen in the video. Perhaps this is the cause of the low frequency vibration!

 

[evantful]

You're video is interesting for me in regards to your harmonic balancer comment. I have the exact same engine and setup. Last year I noticed the balancer seemed to have a very very slight wobble (fore-aft). I decided to replace it this off-season as the old one had rusted badly due to a small leak from the circulating pump a few years prior. It also seemed the two rings of the balancer were slightly mis aligned.

I put on the new balancer and it continues with the exact same slight wobble. And it looks exactly like what yours does.

Also I see you replaced your Alternator, what brand did you go with?

 

[magarmuch]

You're video is interesting for me in regards to your harmonic balancer comment. I have the exact same engine and setup. Last year I noticed the balancer seemed to have a very very slight wobble (fore-aft). I decided to replace it this off-season as the old one had rusted badly due to a small leak from the circulating pump a few years prior. It also seemed the two rings of the balancer were slightly mis aligned.

I put on the new balancer and it continues with the exact same slight wobble. And it looks exactly like what yours does.

Also I see you replaced your Alternator, what brand did you go with?

I ordered from Amazon: