On Sat, 22 Nov 2008 15:10:13 -0600, Nigel Molesworth
wrote:


Yanmar 4JH2-E

Think I found my leak.. I was replacing the water jacket/exhaust
manifold, when I noticed water seeping out of the exhaust. On further
investigation I saw that the exhaust wall had corroded away leaving a
small hole 3/16" X 1/8" right at the end (just before it joins the elbow
- the two walls taper to a thin edge - that's where it's leaking).

There is a drain on the cooler which I then loosened and water came out.

The hole is right at the join/lip between the exhaust and the water
jacket.

I don't think filling with JB WELD or similar will stop water flow -
what does the team think?

Although its obvious that sooner or later it will spring another leak
somewhere else.

(sigh)

It sounds like the exhaust manifold has rusted out ?

It will need to be repaced unless you can get it welded up but I'd
repace it if it was mine. If water gets back into the cylinders you
will have a very expensive repair on your hands.