Heat exchanger gotcha.

[GILow]

Hi all,

Thought I would share this in case it saves someone else the half an hour it took me to track down this particular problem.

Just finished rebuilding the raw water circuit on our engine cooling system. Put it all back together, started the engine... cooling flow was ok, but not much better than when I started the process.

Long story short, after half an hour of poking around I discovered the heat exchanger exit fitting was significantly blocked up with bits of sacrificial zinc anode. A nasty one because the heat exchanger itself was spotless and a visual inspection of the system looked fine.

Having a good raw water filter I was not expecting to have any kind of blockage in that area. If I had been missing some impeller fins I would have expected to find them in a similar place but I would never have expected bits of the anodes to cause problems.

Matt.