Running a diesel in silty river water?

[KodiakMike]

Hi - Last logged in from California, in Australia now! I'm wondering about driving our boat up the Clarence River here, which has had some significant rainfall lately and has gotten pretty silty - water is brown and you can barely see an object one foot down. So, I'm an ocean sailor - are there any bad implications for running this silty water through our Yanmar 4JH3E? We're only looking at 3-4 days, likely no more than 20 hours total. The oil cooler should be fine, it's just pipes and shouldn't silt up. Raw water pump might take a little extra wear but should be OK, I'd imagine. How about heat exchanger - just more pipes, nothing so small that it couldn't handle a little brown water? So...is this the sort of one-off operation in silty water no big deal at all?

Thanks for the help...

[delmarrey]

As long as you have a strainer before your pumps you should be OK!

[Boracay]

My main concern would be that mud might settle into various parts of the cooling system and be baked into place (forming a sort of insulation) or block water flow (possibly in the water lift muffler).

I'd suggest keeping one eye on the engine temperature and the other on the water flow from the exhaust and if it rises above normal the mud might be the culprit. You will also need to keep both other eyes on the river conditions!

Your manual may have suggestions on servicing the raw water system. I'd read that carefully and maybe bring the next service forward.

I'd also suggest inspecting your raw water strainer every 5 hours or so (or at each engine shut down) until conditions return to normal.

[KodiakMike]

yeah mate, thanks. good suggestions. we'll be heading up to northern queensland at the end of the month so should get a chance to flush it all out with "clean" saltwater!

[Tropic Cat]

There is one downside which can't be avoided. The fella who mentioned the cooling system is dead right. Yanmar water pumps are susceptible to silt. The silt works it's way between the pump seals and shaft and destroys the pump.

I have a unique situation where the combination of shallow water and a stream which carries the silt into our marina combine to cause a problem. This has resulted in replacing two water pumps in the last 2 years because of silt. Both times I tried rebuilding the pumps only to discover the abrasive nature of silt scores the pump shafts, eliminating replacing seals as an option. I have 2 Yanmar diesels in my boat.

[KodiakMike]

ok, another good point. our raw water pump is an incredible pain to access... looks like we'll just get brave, though, and risk our 20 hours of river operation!

[Jim Cate]

Mike,

We've done a lot of miles on the Clarence (one of our favorite areal in Oz) including during the floods of 2008. Never had any noticeable problems from silt, but I'll admit that the situation is specific to each engine and its installation.

On the other hand, if the flooding is still active, floating debris and weed can be a real hazard. A huge accumulation of Hyacinth on the rode and the bow caused us to drag slowly downriver in the middle of a pitchy black night... an uncomfortable situation when you're not keen to go motoring about with all the floating crap threatening your prop. Should this happen to you, we found that anchoring across from the pontoon at McLean, right near the shore, got us out of the main stream of junk.

Cheers, and enjoy a great river trip

Jim and Ann s/v Insatiable II lying Gladstone Qld Oz