Where is the water leak?!

[jumpjets]

My engine (5.7L 1990 merc v8) is leaking about 1 gallon of raw water per hour. It leaks on the trailer on muffs, and on the river.

When I pull the drain plug after running the motor, water dumps out.

Where could it be leaking from? I de winterized it myself. I'm pretty sure I reconnected all the hoses and plugs.

 

[achris]

Re: Where is the water leak?!

My crystal ball is in for it's 50,000 guess service.... So you need to get in and have a look around the engine while it's running on the muffs...

 

[jumpjets]

Re: Where is the water leak?!

Well played good sir. I should be more specific!

I have run it on the muffs and looked around in the bilge with an inspection mirror and flashlight. I can't identify any drips from the engine.

I guess I was asking if there is a common hose or fitting toward the rear of a 5.7 merc that goes bad and leaks.

All the easily visible hoses and fittings toward the front of the engine are leak free.

 

[cr2k]

Re: Where is the water leak?!

Supply line from transom, heat exchanger, core plugs inculding on back of block, circulation pump, exhaust manifolds, elbows, risers, etc. You may not see "drips" if it is spraying very fine and collecting on something and running down to the bilge. Wipe things dry and check again.

 

[Bondo]

Re: Where is the water leak?!

Well played good sir. I should be more specific!

I have run it on the muffs and looked around in the bilge with an inspection mirror and flashlight. I can't identify any drips from the engine.

I guess I was asking if there is a common hose or fitting toward the rear of a 5.7 merc that goes bad and leaks.

All the easily visible hoses and fittings toward the front of the engine are leak free.

Ayuh,.... Try a camera, or yer phone,...

A gusher like that oughta be easy enough to find,...

Turn the hose on High, 'n run the motor up to 1500 rpms or so,...

 

[Bt Doctur]

Re: Where is the water leak?!

rotted exaust Y pipe

 

[Grub54891]

Re: Where is the water leak?!

Does it have a water heater? Check that area if it does.

 

[solar7647]

Re: Where is the water leak?!

Is the water in the bilg warm or cold? If its cold the leak is between your inlet and were it enters the engine, the cooler for the PS fluid is in line there and is comanly over looked during winterizing so not uncommon for them to freezeand break. If the water is warm its coming from someplace between were the water enters the engine and its exit. If your lines on the front look good, my next place to check would be the bellows that connect the exhoust risers to the y pipe, they could b loose or rotted out. I would suggest that the next time you look run the engine at a higher rpm, that will increase the pressure n if it a drip at idle it will turn into a spray at higher rpm n will make it easier to see. Also check the seem of the riser and exhoust manifold ... The gasket could be bad or the riser could be rusted threw there.

Good luck