1977 898 Milky oil/Chocolate milk

racinrc14

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Hey fellas, been a while.

I am currently helping a friend get his new aquisition ready for the season. 1977 898 Chevy 305. Long story short, we got it running and while running on the muffs it fills the crankcase with water and eventually blows chocolate milk out both valve cover breather holes, and out the lower unit, which produced a really great sheen of oil/water on my concrete driveway. My friend is frustrated and ready to give up, but I want to help because I'd like a boating partner. Our two modest families get along together well. He doesnt have a lot of money to spend, so what I can get him to spend on it needs to be spent wisely. I have suggested replacing the long block entirely, but he cant afford that. So the next option is to try to determine where the water is getting in, and go about the process of fixing it.

We know without a doubt that the engine had always been winterized properly, and while it was running I detected no leaks around the usual exterior locations of freeze cracked blocks. I understand the block may be cracked internally. My suspicion is either intake gaskets, or head gaskets, or both. Possibly a cracked head, or both. I do not believe the engine has ever been overheated, but heads do crack for other reasons.

So I'd like to get any ideas from you guys (or girls) based on what happened as to what THE MOST LIKELY cause is. I understand there are many causes for milky oil, but we dont have a lot of money to spend and my friend deserves a boat as much as anyone. So we will start with the most likely and go from there. I am hoping to draw from the tremendous amount of experience on this site from people who have had similar situations and what fixed their problems.

I will say I have some experience with milky oil on an old '77 888 ford 302. Leaking intake gasket was the culprit.

Thanks, Tommy
 
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racinrc14

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Re: 1977 898 Milky oil/Chocolate milk

Also worth noting, we have not begun to disasseble anything yet, so possibly a coolant system pressure check would help? Never having done one, could use guidance...
 

RogersJetboat454

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Re: 1977 898 Milky oil/Chocolate milk

Short of a spent set of intake gaskets, a rotted/cracked intake manifold, or the remote chance that a head gasket has blown between a water passage and oil return passage, I don't see how this could be anything else but a crack in the block/heads.

How do we know this was winterized properly? Even a seasoned guy who religiously drains the block and manifolds could forget one of the drain plugs, or could have not cleared the trash from one of the drain plug holes which caused the water to remain in the block.

You could try to pressure test the block, and see if you can hear a leak from someplace. We obviously know it is leaking, but this may be able to give you a clue as to where if you can localize the sound of the leak. You will need to block off the hoses to the exhaust manifolds, and I would use the hose coming from the drive to apply pressure. You will need to rig up a fitting to adapt the inlet hose to a source of compressed air, with some means of regulating the pressure between 15-20lbs. A trip to Lowe's or Home Depot should provide you with the stuff you need to build this if you don't have fittings, regulator, and gauge on hand.

If you find the intake/gaskets are a problem, should be an easy fix. Anything else, and I would seriously consider seeing if you could find a pre '86 305 from a truck in a bone yard. They are really cheap considering most people pass them up for a 350.
 

racinrc14

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Re: 1977 898 Milky oil/Chocolate milk

Yes, exactly what I am fearing. I have the necessary compressor/regulator and will get the necessary stuff from Menards to pressure check it, sounds easy enough.

When he brought the boat home, I had to show him where all the drains were, and while I was at them, I checked them all with a little scribe I made to clear the drains on my own boat, and they were clear, open and dry. I also disconnected the hoses from the front of the exh. manifolds to see if any water was in them, and traces of clean green antifreeze were present. I know this is no guarantee, but leads me to believe it was taken care of previously.
 
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Don S

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Re: 1977 898 Milky oil/Chocolate milk

I am currently helping a friend get his new aquisition ready for the season. 1977 898 Chevy 305. Long story short, we got it running and while running on the muffs it fills the crankcase with water and eventually blows chocolate milk out both valve cover breather holes

Block is cracked or the intake manifold water passage is cracked, (No, it is not a blown head gasket) remove the intake manifold, the problem will be obvious.

Have a look at this thread http://forums.iboats.com/showthread.php?t=369864
 

racinrc14

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Re: 1977 898 Milky oil/Chocolate milk

Thanks Don. Is it still worth pressure checking, even though we KNOW there is a leak?
 
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RogersJetboat454

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Re: 1977 898 Milky oil/Chocolate milk

Thanks Don. Is it still worth pressure checking, even though we KNOW there is a leak?

I suggested the test as a relatively non-invasive way of finding the leak, but personally if it were mine the intake would be off already. When it comes to wrenching, Don is the big cheese around here. I would pull the intake like he says.
 

Bt Doctur

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Re: 1977 898 Milky oil/Chocolate milk

intake may have rotted thru under the thermostat
 

racinrc14

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Re: 1977 898 Milky oil/Chocolate milk

I will hopefully have the intake off tomorrow. I'll post the results. Thanks to all!
 

racinrc14

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Re: 1977 898 Milky oil/Chocolate milk

WE got the intake off, and after about 15 minutes of finding nothing obvious, we decided to pull the heads. There it was, a hole the size of a golf ball in the starboard rear cylinder. Chock up another one to improper winterization. cylinder.jpg
 

270win

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Re: 1977 898 Milky oil/Chocolate milk

wow...thats a good one! Hate to see that.
 

dollarten

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Re: 1977 898 Milky oil/Chocolate milk

Could you give a thickness of the cylinder wall area in the failed area Before you decide it was a freeze up , this could have been a fatigued cylinder wall but if that was the case , it would be on the thrust area of the cylinder ( 6:00 o'clock position . There is considerely more more iron in the cylinder wall than there is near the core plugs .That is usually the area where freeze cracks occur , not in the cylinder wall area
 

Don S

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Re: 1977 898 Milky oil/Chocolate milk

That hole will sure cause problems with the running of the engine :eek: but it doesn't explain lots of water in the oil.
 

achris

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Re: 1977 898 Milky oil/Chocolate milk

but it doesn't explain lots of water in the oil.

:confused: Really??!??!?! I'd say it explains it very nicely... That hole (sorry, GAPING hole) in the water passage will be below the piston rings when the piston is at top... I'd say that was plenty of opportunity for water to POUR into the crankcase...

I'd also say it's a plenty good time to upgrade to a 350... :D :D :D
 

Don S

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Re: 1977 898 Milky oil/Chocolate milk

Duh, wasn't thinking about the piston being above the hole at times :redface: :facepalm:
 

Bondo

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Re: 1977 898 Milky oil/Chocolate milk

:confused: Really??!??!?! I'd say it explains it very nicely... That hole (sorry, GAPING hole) in the water passage will be below the piston rings when the piston is at top... I'd say that was plenty of opportunity for water to POUR into the crankcase...

I'd also say it's a plenty good time to upgrade to a 350... :D :D :D

Ayuh,.... That's just a scratch,... it'll probably hone out.....:facepalm: :D
 

achris

More fish than mountain goat
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Re: 1977 898 Milky oil/Chocolate milk

Maybe JB Weld???
 
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