engine Question

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sndbowen

Veteran Member
Joined
Apr 29, 2020
Messages
58
Location
USA
Vessel Name
Passage - sold
Vessel Make
2010 Mainship 395
I'm trying to determine the purpose of the hose in the following picture of my trawlers engine.

My engine is a Yanmar 6LY3-UTC. Any thoughts?

Image.jpg
IMG_2440.jpg
 
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I'm trying to determine the purpose of the hose in the following picture of my trawlers engine.

My engine is a Yanmar 6LY3-UTC. Any thoughts?

View attachment 105881

What angle is that photo taken at - from the bottom of the engine?

At first I thought it was an oil change hose, but there would be a valve at the engine end.

Could be a blow by hose?
 
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What angle is that photo taken at - from the bottom of the engine?

At first I thought it was an oil change hose, but there would be a valve at the engine end.

Could be a blow by hose?

I added a second photo. This would be the maintenance side of the engine.
 
It's got oil in it though, right?
 
A condensate drain line for the intercooler?
 
That engine is notoriously messy to change the filter. There is a shallow basin as part of the after cooler casting that catches (some of) that oil. That hose drains that basin. So put a container underneath the hose when you remove the filter. Better yet try (and it isn't easy) to wrap a baggy around the filter to catch the oil.

Some people say you can contain the oil that way. I haven't had much success with that.

David
 
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What angle is that photo taken at - from the bottom of the engine?

At first I thought it was an oil change hose, but there would be a valve at the engine end.

Could be a blow by hose?

That was what one of the marina guys thought.
 
What DavidM said. A drain hose for the basin under the oil filter.
 
DavidM correct
Dont expect it to handle a dump of the filter due to the size of the well and hose.
If you puncture and drain most of the filter it will catch a small trickle. Just remember to stick the hose in a jug or it drains into the bilge.
 
What a dopey arrangement for a filter. I wonder if there is a way to move it like you could on a Ford-Lehman 120?
 
I imagine that any shop doing an oil change will charge for the extra time it takes to clean up afterward. Even a few tablespoons of oil can make a mess over time.
 
Its not very messy if you do it right.
Best to puncture and drain the filter in place before removing. The well works for capturing the little remaining and drains via the hose. A paper towel or 2 wipe out the well and you are ready to replace filter and refill.
 
So then you just replace the filter dry?
 
Good question! How long will the engine run without fresh oil while it fills? No damage every time you change the filter? I have no idea how much/fast an oil pump is? This is more about the design of the system.
 
IMO there is no choice but do it dry. I would run the engine briefly to get everything lubed then remove filter. I have spun the starter with fuel off until oil pressure comes up.
 
So then you just replace the filter dry?

My guess is the engine manufacturers who ship us engines with upside down and horizontally installed filters have figured out that there is no harm done. The engines seem to just keep on ticking.
 
As a professional mechanic for 40 years, I have never seen anyone pre-fill an oil filter before installation. Many filters are located upside down or horizontally and cannot be pre-filled. There is a sufficient film of oil on the bearings to protect things until oil pressure is achieved. I had friends at a junk yard that would drain all the oil and coolant out of junk engines and see how long they would run. Most ran for at least 10 minutes at full throttle before seizing. The few seconds it takes to fill the filter causes no damage.
 
Yanmar manual recommends hold fuel stop while cranking when starting after long term storage.
I follow that advice after an oil / filter change.
I usually crank for about 10 +/- secs and find when I then crank normally eng oil P comes up quickly and alarm goes off in a couple secs... no longer than normal start.
 
Fuel off is a great cautious step. If too difficult for a particular boat/setup, as others point out, no need to do anything.
 
Yanmar Question

I am looking at a Monk 36 which has a 145 HP Yamar 6PHM-TE with 4300 hours on it. I'm told this model was not marketed in USA, so replacement parts are hard to find. The boat had a recent inspection and ran well at that time. Does anyone have input on whether this is a "non-starter" for consideration of purchase? Thanks
 
At best you will be in for a long wait for parts to be ordered and shipped to a US dealer. In addition I doubt that any US dealer even has a parts catalogue to know what to order.

From a bit of internet research it appears that that model was an "industrial" engine never intended to be marinized for marine use and I suspect the marinization is minimal, ie no water cooled exhaust manifold.

The Monk is a nice boat but figure the cost of a remanned Cummins 6BT which was usually delivered with those boats, in case something serious happens to that engine. For my part I would probably pay $25K less for a boat with that engine vs one with the Cummins which is only the material part of the upgrade. Figure $10-15K more for installation.

David
 
Thanks to all!

I appreciate all of the good/useful information.
 
Thanks

That engine is notoriously messy to change the filter. There is a shallow basin as part of the after cooler casting that catches (some of) that oil. That hose drains that basin. So put a container underneath the hose when you remove the filter. Better yet try (and it isn't easy) to wrap a baggy around the filter to catch the oil.

Some people say you can contain the oil that way. I haven't had much success with that.

David

I just came out of the engine room confirmed exactly what you told me. From inside the engine room it is not visible, but can only be confirmed by touch. I could see it from the hatch from the salon, but would have never thought that it was a drain for an external basin.

Thanks for your assistance.
 

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