How to flush, clean or remove heat exchangers

some pictures from today. I was only 1830 or so but it only goes up a degree or two to 2000. Skip, I also put a shot of the pressure too. I tried to show water temp but it clipped. It was 87.1.

Smooth water today. That's about as good as it gets in my boat. Any faster or slower and the mileage drops.
I've become very good at rationalizing the fuel burn.....

I hate to say this but I have rarely if ever clean out heat exchangers. Trick is by cutting the hose and adding a valve and a hose connection. After every trip, I have quick disconnects and I attach a water hose from, the dock. Close the water intake valve and open the fresh water valve and there I now have a fresh water rinse. Works every time and I am able to rinse any impurities in all the raw water pipes and hoses.
Best solution that I have used and I learned that while being a commercial fisherman. We did not have the time to do much of anything especially during fishing season and for some of us it was year round.
George

George, I've just read your post and was thinking about it..

Outstanding! I could see me installing a reducing tee at my 2" seacock with a hose bibb cap.

I suppose one would have to evaluate the time tied up to saltwater running time for determining if fresh or saltwater anodes would be in order.
I suppose that saltwater would be more of a detriment than fresh though, even with shorter run times.
Fresh water from the dock would be cleaner that your average lake..
MMMnnn?

Ah, good point Capt J. I suppose that one would have to leave the seawater cock open while the engine is running, cut in the fresh water, then secure the seacock.

Since I'm going to descale my raw water system (for the first time since I bought the boat Jan 6) today, I'll put in fresh water at about 3 psi first to see it it goes through the system unimpeded.

As long as you have the bit that supplies the exhaust or wet lift muffler with water disconnected so it can't fill with water you should be ok.

f you are descaling then you will need to have the outlet led back into the container you are sucking the solution from if you are pumping it around.

The intake air side of the aftercooler is also important. They get coated and eventually clogged with oil from the turbo. Even a new engine will pass oil through the breather and run it through the air intake.

Only if your engine is arranged to return crankcase vapours to the turbo inlet.

Correct me if I'm wrong, but other than much older engines like some detroits, most engines are no longer venting crank case fumes to the atmosphere, rather than running them back through the intake. Where else do they run them to? Downstream of the turbo it's under boost pressure, so there's no where for them to go.

I know of a commercial vessel delivered this year that vents them to atmosphere up the mast

Hook up some valves between the seacock and strainer, run some hose to the stern and flush with fresh water every time you return to the dock. My coolers look just as clean as they did five years ago when they were pulled and cleaned. It's not the hours matter, it's the time sitting with salt in it and growth occurring. Some people might not put 500 hours in 10 years where others might put that in a year. If you think about it when the engine is running and the salt is pumping through not much growth can occur as the water has velocity... You'll also notice the zincs last a lot longer and there is less corrosion of dissimilar metals occurring (inserts and cases) when it sits.

Maybe then pull every ten years to change o-rings/etc?

You will still need to pull the after cooler off and clean the air side but that can be done on an hourly interval - maybe 1000 hours?

I do it with engine running to avoid this problem. You will also not be able to get the water past the impeller in the seawater pump doing this so it'll just build pressure in the line and probably blow the ceramic seal in the pump which is only designed for 10-15psi. Best is to have the engine running...

Simply hookup a garden hose to the back of the boat, go in the engine room, open fresh water valve before the strainer and close the seacock. Five minutes each engine and generator. I have a manifold that distributes fresh water to each of the mains and the genset and valves before each strainer so I can do one at a time as I don't think a garden hose would be enough water flow for all the machinery at once... When shutting down, close the freshwater valve and immediately shutdown. I normally have my wife shut the motor down as I close the valve to minimize any dry run time on the impeller...