lost coolant, milky motor oil

captdre

Seaman Apprentice
Joined
Aug 6, 2007
Messages
34
Hi, getting the boat ready for summer and checked coolant it was low, engine oil was clean and a little high on the stick.
Started engine and the oil is now milky, could it be a bad seal? or is the coolant channels cracked?
engine is Penta AQ145A
Thanks
 

Silvertip

Supreme Mariner
Joined
Sep 22, 2003
Messages
28,771
Re: lost coolant, milky motor oil

Was the engine properly winterized? If not, the engine likely has a cracked block or head or both.
 

captdre

Seaman Apprentice
Joined
Aug 6, 2007
Messages
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Re: lost coolant, milky motor oil

I think so, I have had this boat for 8 years and always winterized it the same way. The only thing I could think of is the coolant, prestone antifreeze, wasnt up to temp range and froze. Coldest we got this winter was -15C for a very short time.
I think for a test I'm going to drain what coolant is left and put it in the freezer to see what happens, lol.
 

captmello

Captain
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Jun 30, 2008
Messages
3,848
Re: lost coolant, milky motor oil

One other thing that can happen is the oil cooler, i'm pretty sure you have one, may be leaking. If this was the case however, you would have water in the oil, not coolent. You're sure its antifreeze in the oil?
 

captdre

Seaman Apprentice
Joined
Aug 6, 2007
Messages
34
Re: lost coolant, milky motor oil

One other thing that can happen is the oil cooler, i'm pretty sure you have one, may be leaking. If this was the case however, you would have water in the oil, not coolent. You're sure its antifreeze in the oil?

The boat hasnt been in the water since August, hasnt ran water through the heat exchanger since then.

I pulled some coolant out and put it in the chest freezer still ahsnt frozen, also topped up the coolant to see if it leaks down again, the oil was completely drained so any liquid in the oil pan will be new.

What parts should i take off first to chase this leak, or test for it? exhaust manifold, valve cover, intake manifold
 

captmello

Captain
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Jun 30, 2008
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Re: lost coolant, milky motor oil

Pressure testing the closed side of your cooling system, before removing any parts would be a way to confirm the system is leaky. The Parts you listed: ex manifold, valve cover, intake manifold, all should be nonfactors.

Are you sure its antifreeze in the oil and not water????
 

captdre

Seaman Apprentice
Joined
Aug 6, 2007
Messages
34
Re: lost coolant, milky motor oil

no not 100% sure it's coolant, but that's all that was in motor over the winter. could water drip onto the motor and get in somehow, or I guess ice could also have built up blocked drain hole and flooded up from the bottom.

How do I pressure test the coolant side?
 

captdre

Seaman Apprentice
Joined
Aug 6, 2007
Messages
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Re: lost coolant, milky motor oil

the coolant in the freezer FROZE!!!! so there's my answer!
I'm guessing the heat exchanger is shot and mixed enough raw water into coolant, diluting it enough to freeze.
so when I pull this motor what is a nice newer motor that would bolt up to the 280 transom plate/housing? AQ171?
 

captdre

Seaman Apprentice
Joined
Aug 6, 2007
Messages
34
Re: lost coolant, milky motor oil

before I take this motor out is there maybe a sliver of hope that a frost plug or something simple/cheap fix to look for. strange that the block would crack and not the heat exchanger/coolant reservoir.
 

GilligansIsland

Petty Officer 2nd Class
Joined
Apr 14, 2010
Messages
138
Re: lost coolant, milky motor oil

Personally, I would do more detective work. Your anti-freeze, froze, because it likely became diluted.

I would want to know what happened so that I would not repeat the same mistake.

I would trace out the damage and get a full picture of what my options were.


Of course, if I had a ton of $$$ I might think any of this worth my time and just have the yard take care of it in time to splash.


But, it doesn't sound like you have a ton of $$$.


Good luck.
 

captdre

Seaman Apprentice
Joined
Aug 6, 2007
Messages
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Re: lost coolant, milky motor oil

LOL, a 33 year old 19 ft starcraft doesnt say BLING, BLING?!?!?!!?? just what does?
Unfortunately this boat is pretty close to the end of her time, if I can find a doner aq145 she'll get a few more years if not she's getting stripped.
 

captmello

Captain
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Jun 30, 2008
Messages
3,848
Re: lost coolant, milky motor oil

a 33 year old 19 ft starcraft

If its aluminum, It may be worth repowering...Or save yourself the hassle and buy a different boat. Unless you're looking for a project, everyone needs one, or five.
 

RogersJetboat454

Commander
Joined
Jul 9, 2010
Messages
2,964
Re: lost coolant, milky motor oil

the coolant in the freezer FROZE!!!! so there's my answer!
I'm guessing the heat exchanger is shot and mixed enough raw water into coolant, diluting it enough to freeze.
so when I pull this motor what is a nice newer motor that would bolt up to the 280 transom plate/housing? AQ171?

What's the temp in your freezer VS how cold it gets outside? Freezers can get awful cold, then again, so can Canada... :D

Pressure test the closed side of the cooling system. Put it under 15lbs of pressure, and let it set for a while. If the pressure drops (especially rapidly), you have a leak. Crack the drain bolt on the oil pan open just enough to allow a little dribble. If water or coolant is present in the oil, it will be at the bottom of the pan, and you will have a good chance of seeing it by cracking the drain plug free.

If results are inconclusive, try this. Put oil in the engine, start it up, and run it to full temp for a while. Shut it off, and let it sit overnight. Repeat the procedure on cracking the drain plug on the oil pan to see if water or coolant has separated to the bottom of the pan.

As far as the "Frost Plug" fix, bare in mind that what everybody calls a Frost/Freeze plug isn't really called that by the engineers who design motors. Their actual name is Core plug. Their sole purpose is just blocking off the holes used by the foundry to remove the sand from the block after it was cast. They were not intended to save the block from a freeze, and often times it has been illustrated right here in Iboats how ineffective they are at their rumored job.

As far as re-powering, you would either need to get an engine similar to yours, or a complete engine/drive package. The 171 is NOT a good option. Parts for it are obsolete, and expensive when found.
 

captdre

Seaman Apprentice
Joined
Aug 6, 2007
Messages
34
Re: lost coolant, milky motor oil

Here's my crack, weird place huh!
IMG_0339.jpg
 

RogersJetboat454

Commander
Joined
Jul 9, 2010
Messages
2,964
Re: lost coolant, milky motor oil

Here's my crack, weird place huh!

Yep... most people have em on their back side.. err.. um.. yep bit of an odd place...:D;)

Looks like you need to go shopping for an engine or at least a block...
 
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