Heat exchanger exhaust elbow

[LadyInBed]

My aluminium exhaust elbow has just started leaking (hole the size of a pea) after about 10 years.
Is this a normal life expectancy?
How long has yours lasted?

 

[Bodach na mara]

I have no idea of normal life for the exhaust elbow as mine was cast iron. I say "was" because what got the hole in my case was the outlet from the manifold. None of your pathetic pea size holes either, you could have stuck your thumb in it and left room for any vegetable of your choice. That was on a motor that was installed in 1974. The hole had been patched before with some sort of plastic metal (I did not know of it when I bought the boat in 1997) have no idea when the hole originally appeared. Probably after about 15 years.

When the new manifold arrived, it would not fit the hole spacing of the elbow, and the elbow was a bit ancient looking anyway, hence the need for a new elbow. I think the problem relates to the corrosive nature of the gas/seawater mix which splashed into the bend and lay there when the engine was turned off.

 

[damo]

I had same problem a couple of years ago, but the elbow was a lot older. It is possible to weld them up (needs some skill and care), but there is always the possibility that hidden corrosion will pop out in the near future.

I replaced mine with a stainless one (OM636 and Bowman heat ex) from West 4x4, Lancaster