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)

--
Molesworth

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.

Wayne.B wrote in
:

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.



If the exhaust backpressure gets high enough to overcome the seawater pump
and empties that heat exchanger of seawater cooling, he'll have lots more
damage than water in the cylinders can make.....