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Please Help Water in the oil 30

6

69birdman

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"The story:
I purchased a 99

"The story:
I purchased a 99 Larson with a VP 3.0 that had a crack repaired. First time I used it a belt broke and overheated bad. Fixed things up and used the boat a few times. I then had water in the oil. I replaced the head gasket and still had water in the oil. I REPLACED the motor with a NEW motor and used my old bolt-ons, manifold, carb, ect. I am now getting water in the oil with the new motor!! I am using a hose on the outdrive with the boat out of the water.
HOW IS WATER GETTING IN THE OIL?? Please help.
Other than a bad head gasket or a cracked block how can water get into the oil? Lots of water not just a little. Thanks"
 
"If you reused the combined in

"If you reused the combined intake/exhaust manifold, did you pressure test it before before installing it? If it is cracked, water may be reaching the intake side, and some of that water will find its way into the crankcase either between the piston rings and cylinder walls, or by hydrolocking and blowing the head gasket."
 
I did reuse the intake/exhuast

I did reuse the intake/exhuast manifold.
I did not pressure test it. Can I just visually check it or must it be pressure tested?
Are there any other possibilities? Thanks
 
"I cannot think of any other r

"I cannot think of any other reasonable possibility other than a crack allowing water into the exhaust side of the manifold and the water finding its way into the cylinder(s) via the exhaust valve. Of course, it could also be that both engines were cracked (heads or block) or both had defective head gaskets, but I think that's a long shot. However, I have seen this type of problem happening before, I believe it was in a Mercruiser 470 which, like yours, had a combined intake/exhaust manifold. The old engine was ruined with salt water ingress. When reinstalling the manifold in the new one, it developed the same problem while testing, fortunately at the shop and with fresh water so no damage occurred. The manifold was cracked (it was an aluminum manifold if I recall correctly).

To test the manifold, you can remove it and install a gasket and a piece of sheet metal between the manifold and the riser, then bolt in the riser and pressurize the water side of the manifold. If it is cracked or wasted, you will see water going into the intake side (or into an exhaust).

Please let us know how it went after (if) you do it."
 
How do I pressurize the water

How do I pressurize the water side?
Where/how do I attach the pressure source to the water side?
Another thing - I removed the water drain plugs from the manifold and the block. I got tons of water from the bolck but none from the manifold. That seamed strange to me.
Thanks for the help.
 
"Your engine does not have a c

"Your engine does not have a crankcase oil cooler, does it? The drawing does not show one (just a power steering cooler), so I assume you don't have one installed. But if you did have one, a perforated tube is also a common source of water ingress into the oil (and of oil leaking into the water)."
 
Thanks for the help.
Part #26

Thanks for the help.
Part #26 is a bracket I think. Did you mean a different part? I have no oil cooler.
If the plate #76 was installed wrong - chould that cause the problem? Thanks again.
 
"Sorry, I meant part 25 (e

"Sorry, I meant part 25 (elbow). Also, part 76 is a restrictor plate (to make the water flow slower) and I don't see how reversing it could make water reach the crankcase."
 
"OK I removed the manifold, ma

"OK I removed the manifold, made a block-off plate from sheet metal and attached a hose to the elbow side. I turned on the water and after a few seconds water was getting into the exhast side. The pressure was about 40-50 lbs.
It also started leaking at the block-off plate.
I don't know if it leaked around the block-off plate on the inside or if I used to much water pressure. I will reseal the block-off plate and try it again. I guess if any water gets into the exhuast or intake side it not good."
 
I just tried it again with the

I just tried it again with the same results.
The block-off plate leaked and some water did get into the exhuast side. Under normal opperating conditions I would guess there is not much water pressure in the mainfold. The mainfold is the common part between the old and new motor. So I guess I will replace it. Wish it cost a little less. Ouch!!
 
"David, if the manifold is in

"David, if the manifold is in bad condition, it only makes sense to replace it as well as the riser. However, if you are getting water on the exhaust side, it could be due either to wastage of the walls around the cooling ports between the riser and the manifold, or because the gaskets are in bad condition. Since (I presume) you have removed the manifold from the engine, and just to be on the safe side, you may want to perform the same test with plate 76 installed instead of the blank plate, and see if water still goes into the exhaust. Also, could you upload some pictures of the mating surfaces between the elbow and the manifold? That would give an idea of their condition."
 
The manifold and riser both lo

The manifold and riser both look great. Very low use and fresh water only. The mating surfaces between the two parts also looks great. When I tested the monifold I only bolted on a block-off plate and did not bolt on the riser. I used silicone for a gasket. I think I will try again with the restrictor plate #76 and the riser. Just to see what happens. Thanks for the help.
If you have any more thoughts please let me know.
David
 
Well I just tried again but wi

Well I just tried again but without the block off plate. I bolted on the riser with the restrictor plate. I turned on the water and guess what? Water was getting in. Funny thing was I forgot to replace the drain plug on the bottom but no water came out. I would have thought water would come rushing out?? So it looks like I'm on the hunt for a replacement manifold. Very expensive part. Thanks for the help.
 
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