Help identify mystery hose on Penta

[redbeard1]

Hello all,


My sailing club recently purchased an Ericson 34 (Penta 2003b with the freshwater cooling attachments). I will be helping with its maintenance and recently spent some time identifying/tracing all the hoses to better understand the boat and to help troubleshoot any problems in future.


One hose still remains a mystery to me. This mystery hose leads to a part (attachment 1 - see red spigot inside yellow circle in picture of another Penta engine, note that engine is missing the circulation pump and the alternator) on the starboard side of the engine that is just under the middle part of the alternator and three or four inches behind the oil filter. By a process of elimination, I think it is a secondary hose from the coolant reservoir (the hose at the bottom of my coolant reservoir splits into two hoses), but wanted confirmation. Also was wondering if anyone can think of a reason for the need for two hoses leading back to engine from coolant reservoir (maybe redundancy in case one hose gets blocked?).


In addition, my coolant reservoir is in the starboard lazarette, not on the engine (I’m not sure why, maybe facilitates fluid check, maybe it helps water heater). The hoses to and from the coolant reservoir disappear behind the water heater (also in the lazarette). A bunch of hoses then reappear from the starboard aft wall of the engine bay and lead to various parts of the engine. One of these hoses is the mystery hose. Given the area where the mystery hose enters the engine, I think it is an extra coolant return hose. I just can’t figure out why it is there only on our boat.


The attached diagram (attachment 2) shows an illustrative cooling system for the Penta engine. I’ve added a yellow dot where my mystery hose enters the engine.


1. Please help confirm mystery hose is coolant hose
2. Please speculate why a boat would have two return hoses from coolant reservoir to engine.


Thanks in advance for ideas/speculations and Happy Thanksgiving.

[JPA Cate]

It looks to me like it's meant to recirculate coolant back to the coolant reservoir.

Ann

[jamhass]

On our 2003t that goes to the hot water heater. Perhaps what you ID as a reservoir is the hot water heater?

[JPA Cate]

On his drawing, it looks like an overflow for coolant, he labeled the reservoir "coolant tank."

Ann

[redbeard1]

Thanks for replies.


Ann – thanks for reply. I agree, I also think it is a hose returning coolant to engine. What has got me stumped is that all the other Penta coolant diagrams I’ve looked at only have one hose back to engine from coolant reservoir tank. My reservoir tank has a ¾ inch hose leading from the bottom as normal. Then after two inches of ¾ inch hose, there is a t-split and a slightly smaller 5/8 inch hose splits off. In the engine bay, I have a 5/8 inch hose that leads to my mystery spot on the engine. After accounting for all the other hoses, by process of elimination, I have determined that it is this slightly smaller hose that becomes my mystery hose.



I wonder if any other cruisers out there have installed the t-split on their coolant reservoir and why they did so.


Jamhass – thanks for the reply. My boat has a separate water heater that is a few feet from coolant reservoir. The water heater is fed from my freshwater tanks and outputs to my head and kitchen. My Penta does have the ability to circulate hot water (See attach 1, items 21, 23). But on my engine, spot 21 is a bolt, and spot 23 contains something linked to thermostat.


Thanks for replies.

[tml]

Our Isuzu 240 had an oil cooler at the base of oil filter with hosed in and out back to engine.
TML

[Horus]

[QUOTE=redbeard1;2263448]Hello all,


My sailing club recently purchased an Ericson 34 (Penta 2003b with the freshwater cooling attachments).

So fresh water cooling; no intercooling system. On my 2003 also fresh cooled in my previous boat, was in that position a bolt on witch was mounted a zinc anode to prevent the engine for corrosion. The mounted bolt/anode brings the anode in the cooling system of the engine.
In this position also can be a plug; or a heather outlet nipple.
See numbers 12 (plug); 42 (Heather outlet) or 26/27 (plug/anode) on this drawing:
http://www.marinepartseurope.com/nl/...-21-11546.aspx

[redbeard1]

TML – thanks for reply. I also thought it might have something to do with oil cooling given the proximity to oil filter, but I learned there is already an oil cooler on the penta 2003 near/under the transmission which is cooled via the raw water system.



Horus – thank you for that link. Looking at your diagram, I’m pretty sure now that my engine has a heather outlet to which my mystery hose is connected.

I’m not sure what intercooling means in your post. To clarify, my engine has a freshwater (currently filled with anti-freeze) cooling system. The freshwater is cooled by passing through a heat exchanger which in turn is cooled via raw water coming in from outside boat (please see attachment 2 in my original post).


Thanks to all for solving this mystery. Any ideas/speculations regarding why the PO would fit an extra hose would be appreciated, for now I'll assume redundancy. Enjoy the Holiday all.

[Sailormanbigd]

I'm not so sure it's for cooling. Might want to check schematic as I think it goes to oil pressure sending unit and attaches to factory engine gauge set? I have a 2003 non turbo in garage and oil pumps out of that hole when I hand crank it? Just an idea.

[jamhass]

Red:

2 thoughts:

1. Perhaps the previous owner disconnected the engine coolant from the hot water heater and rerouted as you found it as an "expediency"?

2. On our 2003t, the tranny has its own oil cooler and the engine oil cooler is mounted under the heat exchanger (both missing from your photo).

[jamhass]

Also:

On our 2003t location 23 is the temperature sending unit.

[deblen]

This plumbing diagram may help you.

https://www.dropbox.com/s/ei0ui9tp6f...20Sys.pdf?dl=0


The "yellow circled" hole in block of VP 2003 was originally for a zinc anode on salt (raw) water cooled models. It is usually blanked off with a pipe plug on fresh water cooled models,but is a direct access to the FW cooling jacket,so can be used for different things.
I installed a mechanical water temp gauge sender in mine.

Here are some other links that may be of use for working with 2003.

https://www.dropbox.com/s/ul4q4iyqt4...iring.pdf?dl=0

https://www.dropbox.com/s/6mudjj9epl...anual.pdf?dl=0

http://www.bluemoment.com/downloads.html

[redbeard1]

Sailormanbigd – thanks for the idea. Although I’m leaning toward it being another freshwater cooling hose, I can check for the oil pressure sensor wires to at least eliminate that possibility. It’s too bad these schematics only show port side of engine. From attachment 5, it seems the sensor may be very near my mystery part.



Jamhass – I’ll recheck the boat’s paperwork to see if PO left any clues. I also determined that only the 2003T turbo models have a separate oil cooler. The oil cooler at base of the transmission that I had seen is for the transmission oil. I’m not really sure how the 2003B cools the oil. Although given how close the cooling jacket is to the oil filter/oil pump, it could be simple conductive cooling.


Deblen – As you and Horus have remarked, it does seem that the yellow circled hole is for access to the coolant jacket. You used your hole for a temp gauge. It appears the PO fitted a second return hose from the coolant reservoir. I just can’t imagine why. Thanks for the links. Love to get my hands on these manuals.


Grasping at straws, I was thinking that if there is no dedicated oil cooler on the 2003B, and assuming the oil cooling is conductive, having a second return hose at that spot might improve fluid flow and oil cooling. But I’m not sure how much fluid usually moves through these Penta coolant reservoir hoses. On cars, I think they are only used to release excess pressure.

[deblen]

Originally Posted by redbeard1

Sailormanbigd – thanks for the idea. Although I’m leaning toward it being another freshwater cooling hose, I can check for the oil pressure sensor wires to at least eliminate that possibility. It’s too bad these schematics only show port side of engine. From attachment 5, it seems the sensor may be very near my mystery part.



Jamhass – I’ll recheck the boat’s paperwork to see if PO left any clues. I also determined that only the 2003T turbo models have a separate oil cooler. The oil cooler at base of the transmission that I had seen is for the transmission oil. I’m not really sure how the 2003B cools the oil. Although given how close the cooling jacket is to the oil filter/oil pump, it could be simple conductive cooling.


Deblen – As you and Horus have remarked, it does seem that the yellow circled hole is for access to the coolant jacket. You used your hole for a temp gauge. It appears the PO fitted a second return hose from the coolant reservoir. I just can’t imagine why. Thanks for the links. Love to get my hands on these manuals.


Grasping at straws, I was thinking that if there is no dedicated oil cooler on the 2003B, and assuming the oil cooling is conductive, having a second return hose at that spot might improve fluid flow and oil cooling. But I’m not sure how much fluid usually moves through these Penta coolant reservoir hoses. On cars, I think they are only used to release excess pressure.

Hi
There is no oil cooler on VP 2003.
Raw water seacock is plumbed to a cooler coil in bottom of transmission,out the other (port) side of tran.,up to RW pump inlet.

The engine plumbing is as shown in first link I posted-EXCEPT-there should be a vacuum breaker(anti-siphon valve) in the pipe that comes out of the RW pump. This valve is located above the waterline to prevent possible siphon/flooding of vessel when unattended. Not absolutely necessary,but a good precaution in the event someone leaves the seacock open.
The other side of the vac. valve is plumbed back to the inlet of the heat exchanger.

Follow the arrows in the diagram to sort out water flow thru this engine. It is a bit weird- especially the thermostat during warm-up.

Len


Service manual - https://www.hisse-et-oh.com/system/a...pdf?1472725469

[deblen]

Another link to how the cooling system works on VP 2003

Volvo Penta 2003 Exhaust Elbow