Blue fluid in the bilge and engine compartment

[osi]

Blue colored fluid ýn the bilge? Not too much. Probably 1/2 handful or less... seems oily..
Also a little bit in down engine compartments? What can it be? shaft oil? but blue? or antifreeze?

SO33i Yanmar 3YM20.

Can you give me a hit before calling Yanmar technician?

Best
Osi

[debenboy]

Osi,
I take it your 33i is fairly new?

I had the same problem on my SO 36i after a few months.
I traced it to a loose hoseclip on the feed to/from the engine cooling expansion tank.

TBF I guess rubber hoses will initially compress a bit over time so that it is not really unexpected. I also had the same situation with the hoses to my water pump, but that was shortly after commissioning and was dealt with under warranty.

Run the engine and check round the clips.

[Mistroma]

I spotted some blue liquid under the engine on my 42DS part way through the first season. Dealer said engine might have been overfilled with coolant.

It appeared again in winter and I also found some in the bilges during a thorough clean pre-launch.

I finally tracked my leak down to the tensioning arm for the alternator. I'd normally assume that the metal bracket would bolt into a solid part of the engine. However, I found that blue fluid poured out of the hole when I removed the bolt holding the bracket. So it seems to go through a cooling passage.

Weird thing to do by design so I assume that positioning was a bit of an afterthought.

If you can't find any leaky hoses then tie a tissue under the bracket and see if it beomes wet. Worth a try if you can't track down the leak.

[Alexandria452]

I had the same issue here on a 45.2 (10 yrs old, not nearly as new as yours) and with this color it is almost certainly coolant. Just a loose top that leaked when we were being rolled nicely offshore. Easy fix.

The coolant reservoir is attached to the engine itself which leads to a lot of vibration. My mechanic suggested that we move it to one of the engine compartment walls. Has anyone done this before?

[Mistroma]

The bottle is fitted on the bulkhead in the 2009 42DS, so Jeanneau must have decided that was better than mounting on engine.

However, that must mean more movement in connection at engine as that will move relative to the bulkhead. Never seen any sign of leakage there in past 3 years so seems to work.

The bracket would be easy to make if you want to try this on your 45.2. It is just an oblong section of stainless sheet with holes at each corner and a couple of 90 deg. bends in the middle (see attached pic.).

[Alexandria452]

Perfect -- thanks for sharing! So my mechanic is maybe worth that $60 / hr he charges me :-)

[yachtsea]

You might want to ask your mechanic to perform a system pressure leak test. He will remove the coolant cap and replace it with a small pumping device. This will put pressure on the cooling system and allow him to find all if any leaking hoses. Works great; we had the same problem with the blue fluid in bilge. There were many loose hose clamps leaking out fluid. ;D

[osi]

Dear captains, I really appreciated for your all replies... Thanks to debenboy, mistroma, alexandria and yacthsea.. I will follow up and apply all your advise this week end.

[rxc]

Mistroma,

Thanks very much for that post. I had a similar loss of engine coolant situation, with some undefined liquid in the bilge, and could not find the leak. But I noticed that it eventually went away, and I never connected it to the time that I had to loosen, and then tighten the alternator arm. Next time I am on the boat I will look at this much more closely.

Many thanks for this hint.

[Mistroma]

Glad to help. I couldn't believe it when I found out that Yanmar had a water channel directly behind a bolt used to adjust a moveable arm. Guaranteed to leak if it is moved.

[rxc]

One last thought - is there some sort of gasket for this bolt, or do you think that one should use some lock-tite or other sealant to seal the hole? I just want to be prepared before I go to the boat (a 3 hr trip, each way).

----------------------------------------------------------------

On more investigation, looking at my parts diagrams, it appears that the alternator bracket on my boat (a 43DS) is attached to the fresh cooling water pump casing, and there does not appear to be any sort of gasket to prevent any leak from the bolt hole. In fact, there is a spring washer there, so it is guaranteed to leak, if the hole does communicate with the interior of the water pump.

The bottom of the alternator mounts on the gear casing, but I don't have enough detail in the parts dwg to see whether there is any cooling passage around the hole. I had to replace this bolt about 18 months ago because it was loose and corroded. The SW pump on my engine(4JH3TE-75) is right there, as well, and I thought that the leak I was seeing was coming from the SW pump area. The leak to the bilge seems to have gone completely away, and I am not losing coolant any more, but this whole matter now deserves some more investigation.

[Mistroma]

The location and shape of the Alternator bracket looks the same on the 4JH3TE-75 as my 2008/9 4JH4AE as far as I can see. The bottom bracket is on the engine casing at the flywheel end and not the gearbox casing. The adjustable bracket is close to the fresh water pump and may well bolt into it. I can't remember as it was several months since I last adjusted it.

Chronology was something like this:
1) Summer 2009 Mopped up small amounts of blue fluid under engine but couldn't see where it came from.
2) Winter 2009 Found blue fluid in bilge. Cleaned and it didn't appear again next year.
3) Summer 2010 Placed more blue fluid & topped up reservoir again
4) Winter 2011 Trial fitting of a larger alternator. Needed to slacken and adjust ajustable bracket
5) Summer 2011 Leak worse but small enough to make it difficult to trace.)

I decided at this point to put a small wad of kitchen roll in a small recess in the block above the flywheel. I found that this was becoming damp with blue fluid. The only thing nearby was the bracket. I took the fan belt cover off, ran the engine for 30 minutes and after stopping it I put a tissue against the bracket. It became damp pretty quickly.

I removed it and sealed it but can't remember if there was an O-ring under the bolt but don't think there was.

I think that I simply let the engine cool before removing the coolant cap briefly to vent any pressure. Then I clipped the hose from the reservoir so that there wouldn't be any pressure to force coolant out. This allowed me to quickly slacken the bolt, dab the area dry and put some blue Hylomar on the metal faces. I adjusted the belt tension and tightened the bracket up fully.

I didn't get any further leaks but had to adjust the position of the bracket during winterisation. So am expecting to seal it again when belt goes back on before re-launch. I think I'll make up a couple of thin gaskets this time to help seal (+ hylomar).

N.B. My leak was tiny 50-100ml per season until I adjusted the bracket. Even then is was probably only twice as bad but I spotted the cause fairly quickly at that point.

[rxc]

Thanks. The gear casing I was referring to is the one on the fwd end (flywheel end)of the engine. It covers the gears that drive the water pumps, the fuel injector pump, and the camshafts. The Yanmar parts catalogue I have calls the entire part group (no 2)a "gear housing", while the main piece is a "gear case".

On my engine, the adjustment bracket bolts into the FW pump, while the bottom of the alternator is attached to this "gear case" with a M10x120 thru bolt, which is the one that I replace about 18 months ago. I have not seen any leakage at the upper bolt on the water pump, but will look closely at it next time we are at the boat. The bottom bolt is where I have seen leakage in the past, but I have ascribed that to SW hose leakage that I thought I had fixed.

This thread has been a good discussion, and it forced me to look more closely at the dwgs, which is a ood thing - I think I have discovered where the oil drain plug is located. Maybe I can start to drain the oil, now, instead of sucking it out of the dip stick.

[Mistroma]

I was tidying up some old pics. and found this one showing where water was running down the engine. After spotting this I dried it out and taped a lenth of tissue over this area. After running the engine for 30 mins. I was able to spot the source.

PS There's a drain plug? I hadn't even thought to look for one and have been pumping out as usual. Must have a look but expect it will be difficult to get a container back out after catching the oil.

[rxc]

According to my drawings, there should be an oil drain plug on the port side of the oil pan, down low in the aft corner. I have no idea whether I will be able to access it, or figure out how to catch the oil, but now that I have seen it on a dwg, I will search a bit harder.

I have attached the page from the Yanmar catalogue. It is Item No 5.

Attachments:

[Mistroma]

I've been so used to pumping out via dipstick for past 25 years that I didn't even check the workshop manual when I bought this boat. RTFM To be honest, I had pile of paper manuals about 9" high and did work through all of them. The engine manual is a PDF and about 392 pages (there's another one as well about 142 pages). So don't feel too bad about not reading them.

Had a good look just now and found it on page 305. Warnings about removing the yellow cap prior to draining.

3JH4E and 4JH4AE:
If the oil filler cap is installed while
draining the oil, the oil cap rubber
diaphragm may be damaged due to a
vacuum being created while draining.

Then it mentions "Pumping out via dipstick" (I remember reading that) and further down a reference to draining via the plug (with a good diagram).

I'll still pump out most of the old oil as it is easy to do. However, I always have trouble getting all of it out. So will make up something to fit underneath and drain the dregs via the plug.

Thanks for mentioning it, I might never have spotted it otherwise.