470, Coolant leaking out of leg.

[Bifflefan]

First off, ALL 470 hater's plz keep your opinions to your self. Thanks

Coolant getting into the raw water side and leaking out the leg when sitting. Not much, its a drip at most.
Heat exchanger and/or exhaust manifold is all i can think of. im siding more to the heat exchanger because it will drain the coolant side down more than a gallon when sitting for awhile.

Im thinking of using Cermic Seal and see if that will do the trick.
Any other thoughts?

Bare in mind this is a new boat to me and has been sitting for 2 years. She runs like a top tho.

 

[Bifflefan]

Re: 470, Coolant leaking out of leg.

Bump into prime time..

 

[stonyloam]

Re: 470, Coolant leaking out of leg.

With that much coolant loss, Likely the riser, not the exchanger. To make sure, remove the aft (fresh water) plug on the exchanger. If clear water (no coolant) comes out, the exchanger is OK. If the riser gasket (prat 27 in this diagram http://www.mercruiserparts.com/Show...r=70&bdesc=EXHAUST+MANIFOLD+AND+EXHAUST+ELBOW) fails the coolant could leak directly out of the outdrive, where the fresh water exits. DO NOT add anything to the coolant!

 

[rjwoodrome]

Re: 470, Coolant leaking out of leg.

agreed the gasket would definatly be the least expensive suspect. hope that's the issue. when you take it apart you can tell right away by the tell tale signs of the gasket material if it failed or not. let us know what ya find.
Rich. a 470 (170) owner...

 

[Eric 3.7LX Alpha 1]

Re: 470, Coolant leaking out of leg.

I too have a 470 which my 4"-exchanger had a leak few years back due to not winterizing early enough. Opened both end covers of the exchanger and found which tube was split. Don't remember if I used a light on the opposite end to look through, or air pressure to find the leak, Once I figured out which tube sanded both ends extremely well, and soldered off that tube closed so the the exchanger is minus 1-tube which was the leak. Engine runs with no change in temp.

 

[Bifflefan]

Re: 470, Coolant leaking out of leg.

I won't have time to tear into it until tuesday or wednesday, but ill post findings and some pics.

Thanks for the ideas....

 

[Bifflefan]

Re: 470, Coolant leaking out of leg.

Update:
Its the heat exchanger.
I cant see anything through the tubes, but there is a definite leak in it. I removed it and took off the end plates. filled the engine side with water and out it came.

My take it to a rad shop see if they can find the one leaking and plug just that one off. May work, may not, but wont hurt to try.