Water leaks

[insanity]

I have 89 mercruiser 5.7L 260H. I have a bad leak coming from some where behind the exhaust manifold. I cannot see where it is coming from, but it is running down on the port side between the second spark plug and the hose that come out of the bottom of it. I believe that if I replace the gasket there it will fix the issue. So far no water is in the block so that is good.

Also the outer unit is getting water in the gear oil. I just replaced the gasket, o ring for the water passage, and the o-rings on the drive shaft. (there was a third in the kit but did not see where it goes. When I drained the oil for it I seen the water mixed in with the oil. Also the vent plug had no gasket, and the fill had a trashed gasket. I found that it needs new ones on both. I will replace them and the oil to see if it stops them.

Am I on the right track here? I have a service manual but any advice would be a great help.

 

[jerryjerry05]

Re: Water leaks

If you have a water leaking from the manifolds onto the block then the manifold is most likley cracked or the riser is leaking/cracked.
There is no water transfer from the manifold to the block that is done through the hoses.The gaskets between the manifold and the block are for exhaust gasses.
The drive needs a seal at all plugs and fill holes. Pressure test it after you replace all the seals.
The manual should have a picture showing all the seals.There is a small seal between the upper case and lower that seals the oil passage between the halfs.Make sure it's there(if you took the drive apart).J

 

[insanity]

Re: Water leaks

Is there a chance that water could leak into the block from the riser?

 

[Bt Doctur]

Re: Water leaks

there is no water passage where the manifold connects to the engine.You will have to remove the manifold first to see where the leak comes from.Risers /riser gaskets do leak but they deposit the water inside the exaust portion or into a cylinder.

 

[insanity]

Re: Water leaks

I drained the gear oil today and flushed it out from the top with about 1/2 a quart of fresh gear oil. It pushed out a lot of contaminated oil. Put new gaskets on it, will see if that fixes it.

Still have to chase down the leak on the manifold. I checked it as best as I could with my hand and it felt a little rough. I also pulled the drain plug and got no water until i shoved a screw in and broke up the rust. This leads me to be leave it may be cracked from freezing.

 

[Bt Doctur]

Re: Water leaks

I drained the gear oil today and flushed it out from the top with about 1/2 a quart of fresh gear oil. It pushed out a lot of contaminated oil. Put new gaskets on it, will see if that fixes it.

Still have to chase down the leak on the manifold. I checked it as best as I could with my hand and it felt a little rough. I also pulled the drain plug and got no water until i shoved a screw in and broke up the rust. This leads me to be leave it may be cracked from freezing.

pertaining to the gear oil , did you refill it FROM THE BOTTOM untill it came out the top???
The plugged drain hole is a normal condition ,happens to the engine block drains also

 

[insanity]

Re: Water leaks

Yes I did refill from the bottom. If the rust is not a major problem then I need to dig deeper.

 

[Bt Doctur]

Re: Water leaks

You need to remove the exaust manifold. Could be a cast plug that at one time was used for a temp sender in the head, they rot away and start leaking .there is 1 in each head. between cyl 1 and 3 and between 6 and 8 . cast iron threaded plug with a square recess.

 

[insanity]

Re: Water leaks

Thanks for the tip!

 

[insanity]

Re: Water leaks

The gaskets where the cause of water getting into the unit. Problem solved thanks to a search here on Iboats.

Now on to the exhaust manifold, it has a good 4 to 5 inch crack in it. Can I patch it with JB weld or more precise the loctite brand? Also I plan to carefully drill the ends in hopes to stop it from cracking any further.

 

[Bondo]

Re: Water leaks

Ayuh,... Throw it away,+ buy New... It's Junk...

It can also be Cracked, Inside, dumpin' water into the motor, causing catastrophic motor Failure...

 

[insanity]

Re: Water leaks

The exhaust ports where dry but buying new is always the right thing to do. I was hoping to finish the season on it. It may have been because the crack is so high up that I had what seemed like a lot of water drain out of it. Which leads me to be-leave that I can patch it.

 

[Don S]

Re: Water leaks

Hang in there, some newbe backyardigan will be along shortly to say what you want the hear.

 

[insanity]

Re: Water leaks

I am going to go with a new replacement and then not worry about it. No since in trashing a good motor to be cheap on it now. I will keep the loctite cold weld on board to a emergency fix to get back to land. An ounce of prevention is cheaper than a pound of cure.

 

[insanity]

Re: Water leaks

I picked up a new manifold today going to wait until weather is nicer to replace it.