1987 5.7 merc not exhausting water out of prop

[Skidlydidlydoo]

I have a 1987 merc 5.7 with a used alpha 1 and it ran last season no problem. Winterized it like every year that I’ve had it but this year for the first start up I had the muffs on it waited for the water to fill and started it. It sounded great and ran fine. Until I realized little to no water was coming out of the exhaust port of the prop. After 5 minutes of running water mixed oil started coming out anywhere it could get out of of the engine. Mainly the oil dipstick housing and that’s when I shut her down. Now I know everyone’s gonna start with cracked this and cracked block or bad head gasket but I want to know is there anything else that could cause it to not release water from the exhaust and fill up the engine? Like a flapper/shutter in the y pipe or anything. I will be doing compression test later in this week but I would like to know more possibilities when going into this. Im an engine guy not an outdrive guy so bare with me please. Thanks

 

[Scott Danforth]

How did you winterize?

 

[Skidlydidlydoo]

I’ve always used stabil for the gas, ran sea foam through the motor, then drained the water from the manifolds. Pulled the hoses for both sides of the thermostat and added rv coolant. Then drained the oil from the outdrive and used something else in it. I can’t remember the product.

 

[wellcraft-classic210]

Hi
Wondering if you drained you engine block // and or if it got filled with the antifreeze // Otherwise it could be what you said not to say.

 

[Skidlydidlydoo]

I drained the block of the water too. Im obviously hoping to find something besides a cracked block. Heads I’m not too worried about I can replace in a couple hours with ease compared to pulling the block. (Knocks on wood)

 

[GA_Boater]

I’ve always used stabil for the gas, ran sea foam through the motor, then drained the water from the manifolds. Pulled the hoses for both sides of the thermostat and added rv coolant. Then drained the oil from the outdrive and used something else in it. I can’t remember the product.

What would you use in the outdrive other than than some type of gear oil?

 

[Skidlydidlydoo]

I’d just like to know if anyone has knowledge of it being something else. Even if it’s a 0.01% chance. I don’t want to pull this motor apart replace it and put it back in just for the same thing to happen to it.

 

[Skidlydidlydoo]

It was just another type of gear oil maybe a higher weight but I always change it back before the season starts.

 

[GA_Boater]

Block or exhaust manifolds and possibly the intake manifold - These crack and water the oil. Cracked block/intake are almost instant milkshake and exhaust manifold can take longer, but the motor won't be running too good cuz water can get into the combustion chamber.

It sounded great and ran fine.

It's the block. Pull the exhaust manifolds and look at the intake and exhaust ports. Might as well do a leak test on them while they're off. Then yank the motor and look for a block.

It was just another type of gear oil maybe a higher weight but I always change it back before the season starts.

Why not use the normal weight lube? It doesn't go bad over the winter and one less thing to do come Spring. I don't see the advantage of throwing away unused lube.

 

[Skidlydidlydoo]

Thanks. I’ll break into it next week after Easter.
I’ve always done it just out of habit with the outdrive. My mindset is just to coat the it while it sits. It doesn’t hurt it just a habit.

 

[QBhoy]

First I’d say that water doesn’t always come out the prop when the engine is on muffs, cold and at tick over. Usually starts when gets warmed up and a few rpm.
Likely not too relevant with your situation. You reckon there is water in oil and overflow. First place I’d hope for is the risers and or manifolds causing this. Other sources aren’t what you want at all.

 

[Bt Doctur]

When the milky white fluid comes out the dipstick it means you mixing water and engine oil. Asiside from a cracked block the intake manifold can rust out below the thermostat and dump water into the engine

 

[Scott Danforth]

pressure test the block and heads. my bet is the motor is coming out.

 

[achris]

It was just another type of gear oil maybe a higher weight but I always change it back before the season starts.

So you drain the gear oil out, refill with something different for winter, then drain that out and fill with the right oil for use in summer? Am I reading that right? If so, why? :noidea: All you're doing is wasting money, and possibly conpromising the 'good' oil with different oil of different weight and an unknown additive package... That's just crazy.

Here's a much easier, quicker and cheaper way to do it. At the end of winter, drain the gear oil and do whatever service you need to on the drive, then refill it with the right gear oil ready for summer. Job done....

Chris.....