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97 5.7 litre v8 mercruiser water in oil!!!!

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sbh6159

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Hi everyone i am new here seeking advice before going out and blowing a hole in my bank account. I have a 1997 crownline with a 5.7 litre v8 mercruiser. I pulled the boat out of the garage this weekend for a first spring start up expecting some sort of problem becasuse like an idiot i did not winterize the boat this year but to my surprise i hooked the hose up turned the key and it fired right up. I left it at idle for about 1 minute and it sounded great but then... i noticed milky oil coming out of the top of the engine where the carb and breather are and my heart sank. i have called around a lot of local marine shops and all are saying cracked block or blown head gasket. Upon noticing the oil coming out i quickly shut the boat off and pulled the dipstick to find water coming out of the dipstick hole. Before i go and pay an un-godly amount of money to have her fixed does anyone have any advice i am no mechanic by any means but i did check the freeze plugs and they are all still in place and none of them are pushed out. any and all advice will be greatly appreciated!
 
If a cylinder head gasket has blown, then you must of course change it before running the engine again. Because cooling water then enters the engine oil. I think it unlikely that the cylinder head has cracked, as you would have noticed things like air bubbles in the cooling system, boiling over and losing water fast last time the boat was in the water and you ran the engines for a period of time. One slight possibility is, could someone have put water into the crankcase, or do you live in a place where moisture could accumulate in the crankcase, so there will be a water build up over time? However, this last possibility is very remote. Changing the cylinder head gasket alone is not a big deal and not very expensive as such.
 
If you didn't winterize it and it ran fine last season, you did not blow a head gasket. You will need to check the manifolds for cracks and you will need to pressure test the engine to determine the cause. Do not pull anything apart until you pressure test the engine.
 
I pulled the boat out of the garage this weekend for a first spring start up expecting some sort of problem becasuse like an idiot i did not winterize the boat this year
Click to expand...

Ayuh,... You have a Cracked Block...

You now need a New motor....

Head gaskets or anything else is just wishful thinking...
 
sinclair thank you for your advice and actually in my garage since it is not heated i do have a blow heater i turn on in there frequently in the witner causing moisture to build in my garage from going cold to hot i dont know if it would be a substantial enough ammount to cause any damage.... what puzzles me is the boat started up first crank and sounded great i would assume with a cracked head or any other major damage this would have not been the case but like i said (i am no mechanic) also if the block was cracked would it have not pushed at least one of the freeze pins out? Is my best option taking it to a marine shop and letting them run a pressure test on the motor?
 
ok now before going to the marine shop since i have never had any major problems what kind of costs am i looking at for any case scenario it might be as in a head gasket replacement intake gasket or so on so i know im not taking one up my rear when they give me a quote.
 
If you have a bad block it will probably be somewhere in the 4-6K range to have the engine swapped at a shop. Don't hold me to that, I may be low by a grand or so.
if the block was cracked would it have not pushed at least one of the freeze pins out?
Click to expand...
No. Those plugs are not "freeze" plugs. They are there so that when the block is cast they can get all the sand out quickly. Why they ever came to be called "freeze plugs" is a mystery. The Chevys in particular often crack internally anyway so even by looking at the outside you wouldn't know until you either find milky oil or you pressure test it.
 
Yes, a freeze cracked engine will very often fire up and run as though nothing is wrong until we see over-heating. Just the nature of freeze damage.

Docksidemarineservices said:
If you didn't winterize it and it ran fine last season, you did not blow a head gasket. You will need to check the manifolds for cracks and you will need to pressure test the engine to determine the cause. Do not pull anything apart until you pressure test the engine.
Click to expand...
Or have your machine shop do this for you...., if you decide to have one built locally!

sbh6159 said:
ok now before going to the marine shop since i have never had any major problems what kind of costs am i looking at for any case scenario it might be as in a head gasket replacement intake gasket or so on so i know im not taking one up my rear when they give me a quote.
Click to expand...
You just touched on a key word.... Quote!
Good for you.
There is a huge difference between an "Estimate" and a "Quote", as I'm sure that you know.
While a solid "Quote" is not always easy to squeak out of these shops, at bare minimum make sure that all work scope is clearly defined.... including "Inclusions" and "Exclusions"! (these are key words)

Get this in written form ONLY.... and take it one step further by asking for a list of potential "unseen" work scope that may become necessary.
These items can also be given an associated line item cost, and spelled out in black and white.
No surprises later on this way. :mad:

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With the amount of water that you have described, and with what Chris has suggested, I too doubt this is head gasket related.
That's quite a bit of water in a short amount of run time.

If the hull is of any substantial length, you can build yourself a Quench Effect combustion chamber design engine getting as far from the fully dished pistons as you can.
Michigan Motors is willing to do this via custom order these days.
Cost increase should be minimal in terms of boat dollars.

Or..... build one via a local machine shop that has SBC Marine Engine experience.
Your crankshaft, rods, tin ware, flywheel, harmonic balancer, Ignition system, and many parts, even including roller camshafts and cam followers, are re-usable.
A good machine shop will learn whether or not the cylinder heads can be re-used.


Just as with drugs.... say NO to these for your new Marine Engine! :mad:
 

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for a boat with the age mine has is it going to be worth it to spend that much money replacing the engine if thas what it needs? i love being on the water i just dont know if a better option would be to sell it and purchase something else which i dont really want to do any suggestions?
 
Your not going to do the work. The labor will be the same whatever motor you buy.

So if you buy a complete motor, fully dressed ready to drop in then the mechanic doesn't have to charge labor for transfer parts from your old motor.

So a rebuilt long block, you need to take parts off your old motor, 2,000 for the motor.

Ok some here will yell who cares a new crate motor straight from gm. Your old parts.

A junk yard motor running good, 900 dollars, your parts.

A motor complete, running good pulled from another boat with a bad hull or drive maybe, 1500.

Pick your poison.
 
well guys i took my boat to a local marine mechanic and it turned out i got lucky with a bad head gasket he replaced all gaskets and i got out of it only spending 300$ took the boat out saturday it runs like it did when it was new and no water in the oil. Im thanking my lucky stars on this one a cracked blocked would have been terrible!
 
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