M40 diesel raw water cooled engine

[DMC]

Hello,

I'm concerned about my E35-3 engine (M40) and if any water may be remaining in it after haul out this winter. Thought if I run the engine for 30 seconds or less while it is on the hard it may expell what water could be left? Is this a good idea or could it cause damage??

 

[KS Dave]

Best practice for a "wet" winterization of the raw water cooling system would include running a couple of gallons of antifreeze through the system as part of your final shutdown. Running it dry will have a negative impact on your impeller and other parts of the system not to mention any trapped water in the system could freeze and cause expensive damage. The Universal M40 manual (also found on in the Resources section on this forum) has the procedures you should follow.

You'll want to get the pricier glycol-based pink RV antifreeze (easiest way to tell, apart from ingredients, is the alcohol-based has combustible warnings on it). I've found that Menard's has the best everyday price on it (I see you're based in OH). Expect to pay $5-6 gallon, but it's cheap insurance in my opinion.

 

[Loren Beach]

O34 - Coupler, Shaft Seal, and Antifreeze

I was having some discussion with another owner about this part of the drive train. Since we were down at the moorage today with camera in hand.... Here it is pictured with the recent-install split coupler. Also visible is the PSS shaft seal. The...

ericsonyachts.org

I just winterized the whole raw water circuit of our engine a week ago. When you do the next haul out, consider changing to the Forespar thru hull valve that makes this process so easy. Rediculously easy.

 

[DMC]

Thanks so much folks! That helps a lot!

 

[DMC]

Oh btw a "Columbo- Just one more thing"; The manual also seems to offer a non-antifreeze solution:
"TO DRAIN FRESH WATER COOLING SYSTEM: All Models Except M-15
1) Remove pressure cap from manifold. (when engine is cool)
2) Open drain cock located above oil filter to drain engine block and head cylinder.
3) Open the in-line drain petcock located below the alternator. This will drain the manifold, heat exchanger and engine fresh water pump.
4) Remove 1/8" pipe plug at lower rear of manifold, to drain manifold separately.
5) Close all drain valves and petcocks when draining has been completed.
I know easy is not always better but do you think this would suffice to protect against freezing?

 

[Captain Pete]

That sounds like draining the green antifreeze from the "fresh water" system which is not typically needed unless you are replacing the 50/50 mix. I would not remove that otherwise as it has rust inhibitors and such, the absence of which will allow for rust in places you don't want and can't see.

What I would recommned you do is put the pink non toxic antifreeze - but only the kind as noted above meant to be good to use in engines as some of the RV and Pool antifreezes have alcohol and can become less effective and may also damage seals and other parts of the system. West marine has a good -50. In Mass I go a step further and use their purple -60, but most folks around here find the pink works just fine.

For my universal i remove the intake hose from the sea cock and put that into a bucket to run fresh water from a hose for a while until the engine warms (might to need to add an extension hose, I also change oil and filter at this time). This running of fresh water also helps remove salt from the system - especially heat exchanger and riser. When ready I then shut hose off and suck up all water in the bucket at which point I then add at least 2 gallons of the pink (purple in my case) antifreese. This puts the antifreese through the sea strainer, raw water pump, heat exchanger, and water lift muffler before it is seen coming out the exhaust. It is also a good way to see how well your raw water pump is pulling water. An alternative way is to keep the hose connected to the thru hull, shut the thru hull and run the fresh water hose and then the antifreese into the opened top of the sea strainer. Loren's suggestion provides a simpler way to do the same thing.

 

[KS Dave]

Great reference - Columbo is one my favorite shows.

I think a definition of terms is important. There are two cooling systems on your engine - a fresh water and a raw water/sea water. The fresh water system is a closed loop and should already have a 50/50 antifreeze/water mix in it. It is directly responsible for cooling the engine by circulating that mix throughout the engine and then through the heat exchanger for cooling. Draining that for winter storage is usually unnecessary.

The raw water cooling draws in water from the outside and cools the fresh water system via the heat exchanger. The output from the heat exchanger is then mixed with exhaust and exits the boat via the muffler and wet exhaust hose. That is the larger risk for freezing as it is just regular water. While the manual does list a procedure (see pg. 14 in the first link) for a dry storage, in my opinion (and many others) getting a high concentration of antifreeze in the raw water system is much more effective at preventing freezing than trying to make sure the intake hose, filter, raw water pump, heat exchanger, wet muffler, and wet exhaust hose are all completely drained of water. Running the system dry is not sufficient to egress all of the water from those locations. You don't want to pay for a new wet muffler or heat exchangers if your freezes and cracks.

TLDR - you need to drain raw water cooling system for winter, not fresh water cooling.

 

[DMC]

Thanks Pete. I have more to think about I guess. I've had the boat for 4 years now and I don't believe antifreeze has ever been used by any of the "winterization guys", that I used to have do it, and the one I have now has a bad back so couldn't do the job on the hard. He says it's not necessary (other than draining the system) but I think I'll go with the forum experts now.

Thanks again!

 

[DMC]

Thank you too Dave for the clarification.

 

[Dave G.]

You must flush system with antifreeze. Too much risk not too. Get a 5 gallon bucket and short hose(3-4') that fits your intake. Pour 3 gallons antifreeze in the bucket, hook hose to intake place other end in bottom of bucket, start engine. Watch stern exhaust until it's spewing pure antifreeze color, shut off engine, done. Don't let the bucket run dry !

 

[Prairie Schooner]

Hello,

I'm concerned about my E35-3 engine (M40) and if any water may be remaining in it after haul out this winter. Thought if I run the engine for 30 seconds or less while it is on the hard it may expell what water could be left? Is this a good idea or could it cause damage??

I'm interested that you have an M40 in a 35-3. Ours is an M25. Do you think it's the original engine? What year is your boat?
Jeff

 

[DMC]

It's a 1988. I bought it off the original owner who sadly has dementia now and I really don't know if it was an option then or not. I know he wanted all the available options at the time but that's all I know. It is a strong engine and purrs nicely on day long engine trips but thats abou it.

 

[Loren Beach]

From observing different engines installed by EY, my take on this is that, like being willing to do all kinds of deck winch types and layouts, the company was reasonably open to customer requests for engine choice in a new boat. These were relatively expensive boats new, and catered to a more-knowledgeable customer base occasionally wanting (and willing to pay for) modifications.
I have seen E-38 models with Yanmar and Pathfinder diesels, for instance.