Flushing the engine

[Captain Steve]

New owner of a 2009 Ranger Tug 25. I found the hose fitting to attach a fresh water hose to flush the engine. Do I flush the engine while its running or while its off?

 

[knotflying]

While the engine is running for two reasons. a) assuming your "T" is before the impeller, water won't pass unless the impeller is working. b) If the engine is not running water can back up the exhaust and into your valves and cause a hydrolock and cause damage.
As a side note, this is why if your engine will not start you should not keep cranking because the impeller will keep pumping water up and cause the same situation.

 

[Levitation]

Tugs of that era don't come with a hose fitting to the heat exchanger. Are we sure? A picture would be nice.

Cheers

 

[Captain Steve]

I will post a pic this weekend, Cummins 150, manual shows the hose installed on a barb.... thanks for this info

 

[RProffer]

I am not an expert on these engines, and we are talking about three different brands of engines with I don't know how many models that are used on the RT and CW boats. I read an article some time ago, and I don't remember where, that said you do not want to apply a pressure hose to the fresh water flush connector on the engine. You want to have a short hose going from the connector to a bucket of water. Use a pressure hose to keep the bucket filled. Believe me, if the engine is running, the bucket will not over flow, nor will it run dry. You can use this same procedure to install antifreeze or to run the engine on the hard.

The reason that was given in the article, was the engine exhaust is also in the same exhaust tube as the cooling water exhaust and if you pressurize the tube with water, you run the risk of forcing water through the engine exhaust valve and into the cylinder, which will either lockup the engine or blow the cylinder. I don't know if this is true for all the different engines we use, or any of them for that matter, but I will not take the chance and connect a pressure hose to the engine. Better safe than sorry.

BTW, If you do not want to cut up a good hose, you can buy a short hose at Lowes. Look in the section where they have the hose reels.

 

[knotflying]

Rick has a very good point. Too much water and it could run into the engine. However, the impeller is pretty tight and I would think it would hold back an abundant amount of water, but I wouldn't take a chance. Opening the sea strainer and putting a running hose in it would be my choice. Even if the water flows over into the bilge, a good dose of fresh water in there won't hurt.

 

[trailertrawlerkismet]

The same strategy that Rick and Mike discuss is what I've always done when flushing or winterizing for the same reasons, with the additional comment that this also applies when doing the same with our generators and or air/heater units.

Jim

 

[Captain Steve]

Thanks all.... A new friend I met at the marina lent me his Sea Flush and will try it out this weekend.

 

[pugtug613]

Is flushing out the engine necessary? I never did that on the last 2 boats I owned. I did do it with my first boat. In my marina, only a few of the boats flush their engines after they use it. If there is fresh water cooling, the only place for salt water is in the exhaust system. Right? Any other part of the engine would be empty due to gravity. Even the elbow should not have any water in it. Right? Am I missing something?

 

[Captain Steve]

Turns out the Sea Flush is made for a much smaller strainer. I just removed the plastic top and adjusted the stream from the hose to keep it full and ran the motor for a couple of minutes. Fairly easy and can't hurt.