Yanmar coolant

[Salty7]

I have a 2012 25SC with a Yanmar 4BY2-150. I am about to change the coolant, was this sent out from Ranger Tugs with Yanmar coolant or something else? I want to use the Yanmar EL coolant but don't want to mix until I'm sure it has Yanmar coolant in it from RT (it has never been changed before). It isn't easy to get all the old coolant out or to flush this system so putting back what was there is important!

 

[knotflying]

Long life antifreeze will do. Prestone extended is what I have used. I change it every year since you can only get out about 2 gallons. You are long overdue.

 

[Salty7]

Thank you knotflying, that is great information. I just bought the boat two months ago, the prior owner was way overdue to do this. It sounds as if you have made the same discovery as me about trying to drain the system, it is impossible to get all the coolant out. At this time I have no running hot or overheating issues at all and I want to keep it that way.

Have you had your heat exchanger or aftercooler off yet? My engine only has 120 hours on it but experience has taught me that is pays to strip down heat exchangers and aftercoolers and reassemble them with Alco grease so they are always easy to service. Looking at them yesterday I am wondering if the engine needs to come out to service them? Possibly they can be kept clean with Barnacle Buster and/or Salt Away and I can put this grim task off for a while?

 

[captstu]

Takes about three hours to remove and replace the heat exchanger. It also takes a few hundred dollars where the hoses that Yanmar recommends you cut rather Irs. The aftercooler cannot easily be removed, or baby.removed all, without removing edge takes about three hours to remove and replace the heat exchanger. It also takes a few hundred dollars where the hoses that Yanmar recommends you cut rather he is. The aftercooler cannot easily be removed, or baby.remove the raw, without removing the engine.

If it isn’t broken, keep it clean, change those eggs, and otherwise leave it alone. Barnacle buster works well. If it isn’t broken, keep it clean, change the sinks, and otherwise leave it alone. Barnacle buster works well.

 

[ALICE J]

I have a Yanmar BY4 180 2011 R27. Last spring I "forced" to pull the engine in order to change all the hoses and have the heat exchangers cleaned, oil and coolant. Getting to the all the hoses and oil cooler was cheaper, time wise, to pull the engine by the Yanmar dealer. I also got to inspect close up the entire engine and engine compartment. Good time to flush all the oil out through the oil plug and perhaps add an oil extractor at the that plug. Check to see if the motor mounts need attention, or maybe just replace them now with the engine out. Remember, rubber deteriorates over time and changing it all out now will give you a greater sense of confidence in the operation of your engine. I also added a water flow sensor to the intake engine water that warned me several times of a partially clogged water intake thru hull, even though the engine temp was okay. It wasn't the inboard water strainer, but the strainer on the thru hull that was partially plugged by seaweed. Partially obstructed water flow will also produce a squealing sound that is produced by lack of water lubricating the cutlass bearing. because that bearing gets its water from the exhaust manifold via the little black hose to the cutlass bearing, which if being starved of sufficient water will bypass the hose leading to the cutlass bearing.

 

[Brian B]

I have followed Knotflying on changing the coolant yearly. There are two locations to easily drain the coolant, on the fresh water heat exchanger you will see a plastic petcock that unscrews, there is also one like it under the turbo. You will get a little bit more out with the one under the turbo. To do a full drain of the system I believe the heat exchanger needs to be removed to get to that drain plug. I periodically run salt away through the salt water side of the system. About 1100 hours on the engine and never had an overheat problem. I do change the impeller yearly.
A 6 year old boat with only 120 hours, you need to put some hours on that baby 🙂

 

[Salty7]

Thank you all for the advice and sharing your experiences. I have decided to adopt the once a year change of the coolant, I was able to extract about 2 gallons and will put a few hours and then do the same again then go to an annual 2 gallon swap. I did a Salt Away flush and I am going to make that a frequent habit. I replaced the water pump impeller and invented a few new curse words while doing it. The previous owners were very lucky, it had the original impeller (six years), all the blades were cracking at the roots and fortunately none had come apart but a catastrophic impeller failure was not far off. I'm going to go and use the boat!

Thanks for confirming, as I suspected, the most time efficient way to completely service this engine, belts, clean heat exchanger and after cooler, hoses, engine mounts etc is to lift it out, hopefully I have lots of hours to go before that becomes necessary.

 

[Brian B]

Salty7 check out my photo album for the modification I made for easier access to the impeller and the front of the engine. There may be a few less curse words expressed. Yes go enjoy your new boat!

 

[Salty7]

Thanks Brian B, I have been looking at that step and trying to decide what to do about it. Modification is definitely on my list before the next impeller replacement!