Lazy man's Heat Exchanger cleaning

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Senior Member
Nov 25, 2007
New Zealand
Vessel Name
Vessel Make
Westcoaster 53 converted to pleasure
The main has been running a little warm under load and the heat exchanger is due for a clean.

The*HE on the Cat 3406 is very large,*a two-man lift*and buried*low in the bilge, below*engine-driven pumps and hoses. There's not enough room to get the end- caps off in place. I didn't want to drain the cooling system as it holds 105 litres*of coolant and it's not due for replacement.*

Fortunately, there*are several zinc position options so I have a Zinc on the top at one end and a plug at the bottom at the other. I drained the seawater from the plug, stuck my finger in and could feel all the calcium etc. on the end of the bundle.*Replaced the*plug and removed the zinc at the other end. With a funnel I* filled the HE with ordinary household white vinegar and left it for two weeks.

When I drained the vinegar a huge amount of "stuff" came with it and the bundle is now clean to the touch. I went for a run yesterday and the engine is running 5deg cooler.

Since this is so easy (and cheap), I'll do it every year!

-- Edited by Bendit on Thursday 26th of August 2010 04:18:23 PM
Good info. Well Done!
That seems like a good idea and I doubt it could hurt anything.* I'm going to try it.

I don't have any plugs but it seems like I could just remove the hoses, plug the outlet, and fill it with vinegar.

-- Edited by rwidman on Wednesday 15th of September 2010 03:35:43 PM
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