Mercruiser 3.0 water leak

[bjarnold1]

I have a 2000 Bayliner 1954 with a Mercruiser 3.0 I/O. After running it on the muffs I noticed a water leak on the right side of the engine just above the oil pan gasket. It appears to be coming from a hole on the block where the alternator wire clamp is bolted to. Do I have a serious problem or just needs to have silicone on the bolt?. I checked the engine oil and there are no signs of water in it.

 

[bjarnold1]

Re: Mercruiser 3.0 water leak

After working on the boat in the daytime the leak is coming from behind the manifold and running down. From what I have seen in other posts it would indicate a cracked block. I ran the engine for about an hour on muffs and the engine stopped leaking. Could it still be a cracked block or something else?

 

[Fishermark]

Re: Mercruiser 3.0 water leak

If I am not mistaken I believe there are a couple of core / freeze plugs there. Best (only ) thing to do is remove the manifold and take a look.

 

[Bondo]

Re: Mercruiser 3.0 water leak

Could it still be a cracked block or something else?

Ayuh,... It Still could be whatever it Is....

Get yourself a Mirror,+ flashlight, or camera, or Whatever,..
And Look....
You should see rust tracks or marks,... Look higher til you see None,...
That is a Freeze Crack prone area,....
Is the motor's Oil Level where it's supposed to be,..??

 

[bjarnold1]

Re: Mercruiser 3.0 water leak

I looked up and it's coming from behind the manifold so I can't tell exactly without removing it. The oil is right where it should be and no weird smell to it.

 

[Bondo]

Re: Mercruiser 3.0 water leak

I looked up and it's coming from behind the manifold so I can't tell exactly without removing it.

Ayuh,... I think iboats sells the Gaskets you're gonna need,....

 

[bjarnold1]

Re: Mercruiser 3.0 water leak

If I had a cracked block would it leak water if the engine was hot, cold, or both?

 

[Fishermark]

Re: Mercruiser 3.0 water leak

If you are asking just for curiosity sake, then I would guess that it would leak while hot or cold - with the engine running.

If you are asking because it has now stopped leaking and you are trying to avoid removing the manifold...

I ran the engine for about an hour on muffs and the engine stopped leaking. Could it still be a cracked block or something else?

Then I would say that is a waste of time. Go ahead and remove the manifold and you will be able to see what is happening.

 

[bjarnold1]

Re: Mercruiser 3.0 water leak

What if it also leaks when the engine is off but is on muffs?. I really hope that it is not a cracked block as I just bought the boat saturday and paid $5000 for it.

 

[Bondo]

Re: Mercruiser 3.0 water leak

Dude,... It Leaks,....
Until you take it apart enough to see Why,.... Nothing else really matters...

 

[Don S]

Re: Mercruiser 3.0 water leak

What if it also leaks when the engine is off but is on muffs?.

Asking "What If" is not going to answer anything, just keeps people busy typing. You will never know what the problem is until you pull the manfold and look. You could find it's actually the manifold and not the block, who knows.
As stated, PULL THE MANIFOLD.
Go up to the Adults only sticky at the top of this forum and download the OEM service manual for your engine, it's free, you need #26.