1996 mercruiser 4.3 water in oil

fen-isl

Seaman
Joined
Mar 31, 2011
Messages
74
Hi guys, have read thru some of the threads and keep hoping its not a cracked block , Bought a beautiful 1996 Chaparral in May, freshwater, garage kept, had my 2nd child about the same time, never got the boat in the water, only time out on it was for the sea trial and it ran great. Hauled it to the beach but never had a chance to use it with the baby and work schedule, so there it sat, would start it once in a while on the trailer for the curious neighbors who thought it was newer than it really is. Anyway was going to winterize it my self but never had and I/o before always outboards, So wife thought I should take it to a shop and have it done, Night before I took it I pulled the engine cover and rear seats so they would not get dirty or messed up, checked the oil, looked like it came out of the bottle. Took it to the shop and they called an hour or so into it and asked me to come on down and look at the oil, they had it in a clear bottle and the oil filter next to it, like like a swirled milk shake. I was bummed, they thought it could be head gaskets,intake gasket, or exhaust risers, has the old style bat wing one piece on it, so the finished the winterization and i took back to beach house. pulled the risers off they looked amazingly clean inside, took them home and filled them with UV dye and water let sit for 3 weeks would check once a week with a bore-scope and saw no seepage, so ruled them out(not saying they shouldn't be replace) just didn't think they were causing water issue, When shop did the winterization they did compression test had 180 psi on all but #5 that had 190, also supposedly some moisture on plug. they said that water could make the compression number higher and believe it may be intake,or head gasket but didn't think it was a cracked block as it ran very well. So 3 weeks ago went out and bought a new trailer so I could bring it home and work on it in my heated garage. I pulled the intake manifold which I thought came off too easy, as I loosened the bolts could here the gasket material stretching as the manifold lifted up, after all of the bolts were removed it pulled off with hardly any resistance, looked at the sealing area saw one little spot where water may have been getting under gasket but didn't leave a trail of any type into engine, Checked down by the lifters saw no obvious signs of a crack,( engine very clean inside and out, no sludge or varnish) I also now know why the oil didn't look milky on the dip stick, the dip stick doesn't actually go into the oil pan, it goes into a separate tube alongside then 90 degrees into the bottom of the pan, so it really never sees the oil in the sump,just the level.So today I decided to pull the head, found nothing under there that says it was leaking,Guts telling me probably the intake, so my question is should I take the head out and have them magnafluxed? speed shop wants 150.00 ahead, says they do a valve job and shave and true it up, or should I just get new gaskets which the Mercruiser dealer says all of the gaskets run approx 240.00 and throw it together and see what happens. The gasket material on the head and block is such a mess looks like a real pain in the butt to get off, was reading the Mercuiser repair manual and it says to coat new head gasket with super seal on both sides, what is super seal? is there any good way to get the block cleaned up so I wont have a leak after I put it back together due to a dirty mating surface? Sorry for the long thread, just wanted to get every thing out there so there isn't 10 questions asking about this and that.. I have pictures. Just a note this was a fresh water boat, that will be seeing salt and fresh water. Thanks for any help you could offer.
 

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jerryjerry05

Supreme Mariner
Joined
May 7, 2008
Messages
17,923
Re: 1996 mercruiser 4.3 water in oil

You need to take a breath between words???
Very hard to read like that.
It's possible the cover was left off the motor and rain worked it's way through the carb?
They make a spray that will help remove the gunk.
Or a wire wheel on an air grinder.
The gasket sets are all over e-bay and a lot cheaper than Merc.
If the valve guides all check clean and no rust then I wouldn't bother with the fix up.
I believe the newer style manifolds are available for replacement.
Check the flappers in the down tubes.Possible they are bad and allowed water back washed into the head??
 

tpenfield

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Staff member
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Jul 18, 2011
Messages
17,621
Re: 1996 mercruiser 4.3 water in oil

paragraphs would be good for you . . .

you missed an opportunity to find the problem before you took the engine apart. A pressure test of the cooling system would have been a good way to find any crack or leak, etc. now that the engine is apart, it will be a bit more difficult, unless there is an obvious flaw.

the oil looks newly watered, so it could still be attributable to the issue being there when you bought the boat . . . Or. . . . Is there a possibility of the engine freezing prior to your winterization ???

anyway, machine shops will want to do a fair amount of work, like milling heads, etc that may not be really necessary. So, keep an eye on your checkbook. The best thing to do at this point is to really find the source of the water. If you don't then you will not know if you money is being spent in the right places. You could pay a lot of money to have work done and not really find the problem.
 

tinkerguy70

Petty Officer 2nd Class
Joined
Oct 12, 2012
Messages
190
Re: 1996 mercruiser 4.3 water in oil

I ran into something similar with the oil looking kind of gray. After a pressure test and a few oil changes then a couple of trips to the river for some WOT runs it all cleared up.
The boat I bought sat for 3 or 4 years with a cover on it, the only conclusion I can come to is that there was excess moisture in the crankcase from setting so long without being started.
Then, it got all mixed up when I fired it up for the first time in years. It looked like new oil on the dipstick when I bought it, just like yours.
It doesn't take much water to milk up oil in the crankcase.
Well anyway, while my situation may not be like yours exactly, I just thought I'd share it before you dumped a lot of money into something that may not be broken.
Just something to consider, hope you get it all worked out.
 

fen-isl

Seaman
Joined
Mar 31, 2011
Messages
74
Re: 1996 mercruiser 4.3 water in oil

Ok so I came up for some air.

To answer some of your questions, had boat winterized in September, no freeze issue then, boat sits under house with 2 covers one is the factory other is grey tarp that goes to trailer frame so the gelcoat on sides doesnt fade. so no possibility of rain getting into it, previously was always garage, Gelcoat looks like new no fade.

As for a pressure test the shop wanted to do that, but they said had to remove every thing from engine to isolate it just engine and intake, they have special plates that they bolt up to block ports and then press test the block/heads/intake. obviously this cost about 90 and hr so i decided to research it more on the internet, as you can see I waited until now from September to do this, talked to a couple of shops, read a lot of threads on here so I didn't just decide to do this over night.just thought I would find something more when I opened her up, was really glad to see how clean it was. have worked on cars where the oil was never changed and was like black fudge under the valve covers

As for a new long block not an option this year, but if after I get it back together still have a problem will do next fall/spring just not in budget (2 kids in daycare over 20k a year) plus just got trailer so I could get it home to work on it.

Thanks
 

tpenfield

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Re: 1996 mercruiser 4.3 water in oil

Do you think that the problem exisited when you bought the boat?
 

stonyloam

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Mar 13, 2009
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5,827
Re: 1996 mercruiser 4.3 water in oil

So after all that, what it boils down to is that all you know is that there was some water in the oil. Since it is apart there is no easy way to diagnose the problem. If there was no sign of an external leak, it would not be unreasonable to conclude that you do not have a freeze cracked block, as that would likely cause both an external and internal leak. I would suggest that you buy the OEM gasket set (at least the head gaskets) and put it back together, change the oil and run it to see if the problem is real, or just an anomaly caused by condensation or some other accidental water incursion. It would cost a little money but would at least allow you to properly diagnose the problem (if there is one), and could save in the long run. Anyway just IMHO, good luck.
 

HT32BSX115

Supreme Mariner
Joined
Dec 8, 2005
Messages
10,083
Re: 1996 mercruiser 4.3 water in oil

After looking at your pictures, it appears that your exhaust ports are rusty.

That can be a result of riser gaskets leaking, cracked riser(s) and/or exhaust manifold(s) .

Since you didn't take the opportunity to pressure check the block and heads before disassembly, I would also suggest just putting it back together since there's no easy way to tell what's leaking.

By the way, leaking risers and manifolds don't usually allow enough water into the crankcase to make the oil appear "watery". (unless you have a couple of broken rings etc.)

Your water in the oil is either from a cracked block, cracked manifold or it ran in from above (rain water)

After you get it back together, pressure check the block and heads!

The sticky above has an explanation of how to do it.

[h=3]Sticky: MUST HAVE Technical Information for DIYers.[/h]

Good luck,


Rick
 

tinkerguy70

Petty Officer 2nd Class
Joined
Oct 12, 2012
Messages
190
Re: 1996 mercruiser 4.3 water in oil

If it where me (and it isn't), I would clean it all up really well and put it back together with some quality gaskets.
Then, I would do a good pressure test and determine if there is still a leak. You should be able to fashion everything you need to do the test yourself. The biggest ticket item will be a source of compressed air, regulator, and a valve of some sort.
Until you know for certain if there is indeed a leak, or where it is, you're just wasting time and money.
 

fen-isl

Seaman
Joined
Mar 31, 2011
Messages
74
Re: 1996 mercruiser 4.3 water in oil

The exhaust flappers in place??

Yes the flappers are in place, also have had water and uv dye in the manifolds for over a month now, and no leakage, they are the one piece unit though, and look very nice inside, I am going to replace them with the new upgrade kit anyway. Work is a little busy so probably wont get a chance to put it back together for a few weeks. Still have to clean up the head and block to get the gasket material off. I will keep updating,

I really don't believe its the manifolds though, because wouldn't there be rust in the cylinders or valve stems, one person on here says the exhaust valves look a little rusty, but that is just on the fire side of the valve and it is so faint,

Thanks,
Rich
 

ENSIGN

Lieutenant Junior Grade
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Jun 21, 2009
Messages
1,179
Re: 1996 mercruiser 4.3 water in oil

It would be a good idea to pressure test the heads and intake before you reassemble the engine.That way you can eliminate these when you do a final pressure test.
 

300sflyer

Chief Petty Officer
Joined
Jan 1, 2009
Messages
610
Re: 1996 mercruiser 4.3 water in oil

It would be a good idea to pressure test the heads and intake before you reassemble the engine.That way you can eliminate these when you do a final pressure test.

Pardon my ignorance, but how do you pressure test both the heads and intake before the engine is re-assembled?
 

tpenfield

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Staff member
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Jul 18, 2011
Messages
17,621
Re: 1996 mercruiser 4.3 water in oil

Yea, lots of stuff to block off, etc in order to close up all the passages. If you can do it, you will probably find the leak/crack and therefore not need to re-assemble . . .
 

ENSIGN

Lieutenant Junior Grade
Joined
Jun 21, 2009
Messages
1,179
Re: 1996 mercruiser 4.3 water in oil

To save yourself some time take the heads and intake to a machine shop and have them pressure/vacuum tested.
 

fen-isl

Seaman
Joined
Mar 31, 2011
Messages
74
Re: 1996 mercruiser 4.3 water in oil

:Hi guys, As last posted I would get back to you(January) and let you know how I made out ,I thinks I have good news, Finally got the engine back together, took it out for a shake down on Saturday night,about 2 hrs idle speed and W.O.T. got back in around 10pm, and all seems, good. Will definitely know better this week when I pull her back out of the garage and pump out the oil and filter. I believe my water leak was from the intake gasket, Although I changed a lot of parts, head gasket, head bolts, intake gasket and intake bolts, flapper, impeller and got rid of the one piece manifolds and went with the aluminum 2 piece manifolds from performance tech,(which saves about 40lbs) She runs great, rechecked oil, level has not risen, no foam under valve covers. Just wanted to thank every one who answered my many post over the last 6 months.. ...... Might give a little hope to some others who have water in their oil that it may not always be a cracked block..:)
 
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