No thermostat=water in oil?

[duped]

As some may remember, I posted a thread Friday about replacing intake gaskets trying to track down a problem of water in oil. It seemed pretty clear to me that one was blown and heavily corroded. I spent 6 hours just cleaning the gasket surfaces and prepping. I went so far as use fine grit stones to remove all corrosion and surface defects on heads and manifold. Everything was a machine surface when done. I used marine gaskets and aviation glue on both sides to ensure a seal. Torqued in the proper pattern to 30ft lbs. Also inspected the intake manifold and lifter valley for cracks and found none, supporting my theory that this block CAN'T be cracked. Water ingestion issues JUST started in the middle of summer and have been draining and winterizing properly since 2009 when I bought it. I ran diesel and the oil and then changed it again after the job was done.

In short, I'm 100% certain I did it properly, thanks to the help of folks here.

Anyways, I got it out on the water yesterday, and I am still getting water in the oil, although it seems like less. Approx 1 quart in 6 hrs run time, some trolling, some cruising.

When I did the gaskets, I found out it has no thermostat installed. What reason, i dont know. It did need an impeller when i bought it, so that may be it. I ordered one but until it arrives im sitting here speculating and looking back... recalling all the steam that comes from the valve cover vent tubes during running, especially this year with the water being colder. Now I'm to understand that this vapor will usually burn off once the motor is up to temp, but it never gets there without the TSTAT...so could this be the source of my oil contamination? There's an awful lot of moisture/cheese under the valve covers which could support that theory. Just so strange. Thoughts?

 

[Another retired guy]

Re: No thermostat=water in oil?

I can see that a hotter block will remove more water ( steam) from the oil, but I don't see how the absence of a thermostat can be the cause of the water getting into the oil

 

[ricohman]

Re: No thermostat=water in oil?

You should not have steam coming out of the valve cover. Any bit of condensation is burnt off pretty quick and although some people mistake blow by for steam, I don't think that is the case in your situation.
Having no t-stat will not affect water getting into the engine. You got more digging to do but you are getting water inside the motor.

 

[NHGuy]

Re: No thermostat=water in oil?

Going without a thermostat will keep the temp so low that the motor could not burn off moisture in the oil.
But, that amount of water you are getting is more than condensation.
You need to block off the cooling system and pressurize it, then listen for air leaks.
There is no other path of entry for water.

 

[Maraian]

Re: No thermostat=water in oil?

I had overfilled milky oil, replaced the exhaust manifolds and risers, now my oil is normal! They say that water is not supposed to make it past the rings, but it does! Also, no evidence of low compression!

 

[Bondo]

Re: No thermostat=water in oil?

As some may remember, I posted a thread Friday about replacing intake gaskets trying to track down a problem of water in oil. It seemed pretty clear to me that one was blown and heavily corroded. I spent 6 hours just cleaning the gasket surfaces and prepping. I went so far as use fine grit stones to remove all corrosion and surface defects on heads and manifold. Everything was a machine surface when done. I used marine gaskets and aviation glue on both sides to ensure a seal. Torqued in the proper pattern to 30ft lbs. Also inspected the intake manifold and lifter valley for cracks and found none, supporting my theory that this block CAN'T be cracked. Water ingestion issues JUST started in the middle of summer and have been draining and winterizing properly since 2009 when I bought it. I ran diesel and the oil and then changed it again after the job was done.

In short, I'm 100% certain I did it properly, thanks to the help of folks here.

Anyways, I got it out on the water yesterday, and I am still getting water in the oil, although it seems like less. Approx 1 quart in 6 hrs run time, some trolling, some cruising.

When I did the gaskets, I found out it has no thermostat installed. What reason, i dont know. It did need an impeller when i bought it, so that may be it. I ordered one but until it arrives im sitting here speculating and looking back... recalling all the steam that comes from the valve cover vent tubes during running, especially this year with the water being colder. Now I'm to understand that this vapor will usually burn off once the motor is up to temp, but it never gets there without the TSTAT...so could this be the source of my oil contamination? There's an awful lot of moisture/cheese under the valve covers which could support that theory. Just so strange. Thoughts?

Ayuh,... drain the block, 'n rig it for a Pressure test,....

Sounds like a cracked block, a pressure test will prove or disprove that, 'n help ya locate Where, by listenin',...

 

[04fxdwgi]

Re: No thermostat=water in oil?

Which engine / drive is in the boat?

Do you have operating exhaust shutters installed downstream of the risers? If you ingested water thru the exhaust while sitting, seems as though you would have hyrdolocked the engine. A quart is a very large amount.

The lack of a thermostat will prevent an engine from getting hot enough to "burn off" moisture / condensation that will usually form inside the valve covers, on the dipstick and under the intake manifold as outside moist air temerature changes, introducing condensation on to cold metal. But one quart of water isn't condensation / moisture, it's a leak.

One quart of water into the engine in 6 hours is a HUGE problem and not "moisture in the oil". You need to pressure test the cooling system to find the leak. There is a leak / crack someplace to allow that much water in, especially on a low pressure system like raw water cooled setup. Water is in 3 places that have direct access to oil: Block, Intake, Heads.

A cracked exaust manifold / riser will introduce water to the oil, but usually on a sitting engine. A running engine tends to blow it out the exhaust stream.