2005 MERCRUISER 3.0L Engine Leaking Water Behind The Exhaust Manifold

[f1nd]

Winterization was done correctly, as it has been since 05. Only has 68 hours on the clock. Couldn't be a cracked block already, could it? Water leaking about 1/2 way back to the manifolds rear (about engines center on right side), and the water is leaking down the block. A cracked block is just to hard to belive at this point.

 

[Bondo]

Re: 2005 MERCRUISER 3.0L Engine Leaking Water Behind The Exhaust Manifold

Winterization was done correctly,

Ayuh,.... If that statement is correct,... It ain't cracked....

You gotta narrow down where We're looking... Where, Exactly is it Leaking....

 

[f1nd]

Re: 2005 MERCRUISER 3.0L Engine Leaking Water Behind The Exhaust Manifold

First and foremost, thank you for responding. When looking at the engine, the manifold is on the right side as you know. Follow the manifold halfway (in front of the carb). When the boat is running, water comes out behind the manifold and leaks down the block. I did not have a mirror available to see were exactly, but it looks like between the 2 and 3 cylinder. It runs down the block on the side under the manifold. Again, thanks.

 

[blg2007]

Re: 2005 MERCRUISER 3.0L Engine Leaking Water Behind The Exhaust Manifold

Hello,

I hate to inform you but more than likely you have a cracked block. This is the most common place a 3.0 cracks plus there is nothing else that would leak in this area except the manifold drain plug, which is at the very back bottom of the manifold.

Check your engine oil. If it appears milky, the engine is trashed.
If there is no water in the oil jump with joy! You have some options for repairing the problem.

Heres your options:
-You can have the block stitched, or try to do it yourself :http://www.locknstitch.com/Repair pdf files/Cummins 5.9 crack repair instructions.pdf
-You can take the chance of having it welded, which is costly and has a high failure rate because the cast iron block does not handle the intense heat well.
-You can use a metal epoxy on it. Example JB Weld. This is my preffered choice. I've done this, never had a problem. I was told it would outlast the life of the boat. The best part of this is its cheap. $4 for JB plus cost of manifold gasket.

Hope I have helped! Happy Boating!

 

[f1nd]

Re: 2005 MERCRUISER 3.0L Engine Leaking Water Behind The Exhaust Manifold

Thanks for the response. Would Marine Tex work???? If it is cracked.

 

[blg2007]

Re: 2005 MERCRUISER 3.0L Engine Leaking Water Behind The Exhaust Manifold

I've never used it personally but a lot swear by it. Can it bond to cast metal? If so I dont think you would have any issues, just make sure it will hold up to high temps.

 

[f1nd]

Re: 2005 MERCRUISER 3.0L Engine Leaking Water Behind The Exhaust Manifold

Yep, the block was cracked. Unbelievable for a boat with 68 hours on it. Marine Tex here I come.

 

[1980Galaxy]

Re: 2005 MERCRUISER 3.0L Engine Leaking Water Behind The Exhaust Manifold

keep an eye on that engine oil. i had the same problem and ran it on muffs for a while and everything looked OK except for the small water leak coming from the crack. then i took it out on the lake and ran for about 2 min and checked the oil and found chocolate milk. good luck and hopefully its just an external crack.

 

[f1nd]

Re: 2005 MERCRUISER 3.0L Engine Leaking Water Behind The Exhaust Manifold

I did check the oil yesterday and today. The boat was running well yesterday when I discovered the leak. I was running it about 4000 RPMs on the river for about 30 minutes. No milky oil. I checked the oil this AM before and after I started it. I just wanted to ensure that in fact no water in the oil existed, which it did not. I just want this temp fix to last me this summer, then I will drop a new engine in it in the fall.

Now another million dollar question? Do I need to drill either end of the crack to prevent it from spreading??

 

[1980Galaxy]

Re: 2005 MERCRUISER 3.0L Engine Leaking Water Behind The Exhaust Manifold

I did check the oil yesterday and today. The boat was running well yesterday when I discovered the leak. I was running it about 4000 RPMs on the river for about 30 minutes. No milky oil. I checked the oil this AM before and after I started it. I just wanted to ensure that in fact no water in the oil existed, which it did not. I just want this temp fix to last me this summer, then I will drop a new engine in it in the fall.

Now another million dollar question? Do I need to drill either end of the crack to prevent it from spreading??

do a search, there are a lot of posts about what you could do with that crack as far as drilling it, welding it, jbweld... all that stuff. i never repaired a crack like that but my opinion would be if its gonna be a temp fix just for the summer, just grind the spot down and put the jbweld stuff on there and it should hold (from what i hear). again, i have no experience with it but i did look it up cuz i had the same problem on my engine but later found out i had an internal crack.