Engine was Full of Clear Fluid when I drained oil

[pauldavidcook]

Good Afternoon,

I recently purchased a 2010 Tahoe Q4 from an auction with a Mercruiser 3.0 for a project for me and my kids to work on. When I checked the oil, it did not appear to have any oil, but it did have water droplets. I pulled the drain tube out, and approximately 2 gallons of clear fluid came out. Once the clear fluid came out, about 2 quarts of milky oil came out. I pulled the spark plugs and ejected the fluid that was in the block. I added Fresh oil and let sit for a few days. I changed that oil and it was also milky. Once I added new oil in, I cranked the engine and it fired right up for a couple of seconds. I did not want to run it as I am sure the engine is still full of sludge. The boat is immaculately clean (see pics). 2 questions -
1. Could the fluid be from pickling the engine? The clear fluid did not have a strong smell for me to identify it. Worst case it was water, not sure how it would be completely full of water though.
2. What is my best approach to get the sludge out? Will engine flushes damage the seals? I’ve read pouring kerosine down the block is good. At what point should I fire it and let it run?

Thanks for your help! I love projects like this and value your help immensely.

 

[Scott Danforth]

its water

how was the motor winterized?

buy cheap oil and change it, run for a few minutes and change again.

 

[flashback]

Well I believe you guys have a project..2 gals of water say's it probably wasn't winterized. Try the cheap oil and a few changes, you might get lucky..

 

[pauldavidcook]

its water

how was the motor winterized?

buy cheap oil and change it, run for a few minutes and change again.

I do not know how or if it was winterized. I did notice a freeze plug had been removed though.

 

[Scott06]

I do not know how or if it was winterized. I did notice a freeze plug had been removed though.

If a freeze plug was pushed out it likely froze from lack of winterization

 

[pauldavidcook]

If a freeze plug was pushed out it likely froze from lack of winterization

If that’s the case am I wasting my time with this? It fires right up.

 

[flashback]

Put a new core plug in it, cheap oil in the crank case and then give it a go. With a water supply to the drive, if the oil pan fills with water you have your project... A replacement engine..

 

[Scott Danforth]

Core plugs are not there to prevent cracking the block

They are there to get the core sand out during casting

Start looking for a new motor

 

[Scott06]

If that’s the case am I wasting my time with this? It fires right up.

Would put a core plug in and pressure test the cooling system, but unless the water got in the crank case another way its heavily pointing to a cracked block.
look at block just below the head on manifold side bet you will see a crack there and on manifold as well.

if rest of boat is in good shape see if you can find an older boat with 3.0 on craigslist that is clapped out, jank the engine and junk the rest.

 

[Jmunk]

Over the years I’ve bought a few boats with 3.0L‘s that I knew were cracked externally on the block, just under the manifold. I fixed them with JB Weld after grinding out a “V” in the crack and drilling out both ends so it wouldn’t run any farther. They ran fine for years with no internal cracks.

It sounds like it wasn’t winterized, you have a cracked manifold and/or cracked block. There is also the chance water entered the engine through the spark arrestor and filled the crankcase, but that unlikely given that a core plug was out.

 

[dubs283]

I pulled the drain tube out, and approximately 2 gallons of clear fluid came out.

Clear fluid in a boat engine might be water.

My guess is based on provided info with regards to a clear fluid and casting plug "removal" you own a freeze damaged engine and have the project you're looking for.

Best method for removing oil sludge from an engine ime is swapping one quart of oil for mineral spirits. Run to temp and change oil/dump filter as needed.

After oil is clean a shakedown/italian tune up is required to verify long block condition

Engine issues aside your tahoe boat will continue to keep you and your kids busy with projects/fun

 

[tank1949]

If that’s the case am I wasting my time with this? It fires right up.

Pop one back in but I believe you are in for a motor replacement.

 

[04fxdwgi25]

I would try the oil change and pop in one of those expanding freeze plugs to run it, but would not have high hopes of being that lucky. The block or head are more than likely freeze cracked and an engine swap is in order. I see no other way that amount of water would be in there, considering zero knowledge of how, or if, it was winterized.

At least swapping the 3.0 is super easy and can be done in 1 or 2 days with a little help. They are readily available in rebuilt long blocks and they are not hard to find used using Craigslist / fleabay and such. Where are you located?

Otherwise, that boat looks pristine. Plus, I would guess you got it at a steep discount, being an auction boat.

 

[Grub54891]

When changing the oil, add a half can of sea-foam. run it and change it about three times. The sea-foam helps loosen the sludge. Back years ago we used kerosene.

 

[tpenfield]

Greetings . . . and welcome to iBoats.

What did the clear liquid taste like? j/k

It sounds like your project just got bigger. You would probably not want to run a cracked engine block, as you never know if it will have a catastrophic failure (ka-boom).

If you want, you could try to set up a cooling system pressure test to verify if the engine block (and/or manifold) is cracked.

 

[Bondo]

Ayuh,..... Welcome Aboard,...... Unfortunately, it's a 99% chance you need another motor,....

 

[Grub54891]

All the core plugs on mine were blown out when I got it. I replaced all of them in one afternoon, included pulling the motor and re-install. The next day I took it out and test ran it. No water in the oil. Still running it 5 years later. But it did not have water in the engine oil itself before replacing the plugs. Best I can figure it froze just enough to pop the core plugs, then it must have warmed up and the ice drained out. Got lucky, even though I have a spare motor I haven't needed it yet. Water in the oil itself isn't as good. I'd be testing the cooling system as others have stated.