Disaster!!!- sequel

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For those of you that remember my original post:-
Disaster!!!
#1831123 - 20/04/2008 21:04 (sorry, don't know how to link)

The yard has just called me to say that they've had the engine out and refilled the sump followed by a test run- no evidence of an oil leak from anywhere??

They are going to give it an extended run during the course of the afternoon and if that doesn't produce a result then this incident is surely a mystery.

Being a pessimist at heart, I imagine that the cause will become clearer as the season wears on
 
I have a Bukh 23 on Kate. That has recently done the same thing. I've cleaned the oil out of the bilge, pumping it into a bottle via a small hand held pump. I refilled the engine and though it does lose a bit still I can't find where it came from.
I do have a LARGE spare can of oil on board now!
 
That's interesting.

See the previous post- if you've eliminated the main contenders then we are both faced with a mystery.

Main contenders reminder:- loose/corroded oil filter- badly seated oil filter- oil supply pipe from oil pump banjo union to rocker box known to corrode and leak- loose sump drain plug- drain plug modification, to give easy access for oil change, incorrectly done resulting in split/perished hose and thus leaking.
 
I don't know that motor, but is there an engine breather somewhere? If there is, is it clear?
If an engine breather becomes blocked the normal blow-by can pressurise the engine, and then seals / gaskets that under normal conditions do not leak, could start leaking.
Try carefully undoing the oil filler cap (or dipstick) while it's running, if there is some pressure there when you release it, then check for a blocked breather.
 
Sounds like the same thing happened to us on our Yanmar. You say the old oil seal was still on the face of the engine block when you removed the oil filter, so when you had replaced the filter with a new one last spring there were then two seals back to back. At least it lasted a year - ours lasted just two weeks. Luckely we had the engine on idle when the alarm came on and all the oil had been dumped into the bilges. I can't understand how this has happenend as the oil seal is recessed into the filter with a flat face to go against the engine block.
 
Since the oil filter base is out of sight when the alternator/starter/flywheel are in situ I can't say if the separated filter seal I removed came off the filter I've just replaced or not as I didn't think to check it- at that time all the other gear was in place and I just unscrewed it by feel and dumped it in the container containing all the recovered oil from the bilge.

If it was from a previous filter then it could well be what you say and obviously something I must take care to avoid again.
 
I've been pondering the pressure idea, and as yet I don't know about the breather but it didn't eject from the dipstick holder.

Since the only thing I did this year was to top up the oil level(about a litre) I've been trying to figure out how that action may have caused the problem

edit content:-


I've just spoken to the very nice folk at Bukh to update them on the ongoing saga and the indicators are that in my adding, up to, 1 litre of oil to correct an oil level at 'minimum' to 'maximum' on the dipstick markers this is much too much as the sump only holds 1.75 litres.

Seemingly the dipstick rubber cap which holds the dipstick in place in its tube should be bonded to the 'stick' and it has been known for it to become separated, thus allowing the cap to move one way or the other along the stem- this would result in a false reading of engine oil level.

In my case it sounds likely that I've inadvertently added far too much top-up oil which could have lead to it syphoning out of the engine- although this would be a first and not something Bukh could comment further upon.

There is no breather just an internal weak vacuum pump which once it plays up would lead to a steady loss of oil, not intermittent nor substantial at any one time
 
[ QUOTE ]
If it was from a previous filter then it could well be what you say and obviously something I must take care to avoid again.

[/ QUOTE ]

From all that you have found and done this does seem the most likely cause, it is not uncommon and I remember doing the same on a car, luckily as soon as I turned her over the oil gushed out all over the floor, so switch off scratch head, curse the gods (and self) and remove filter and old seal, refit filter, try again, all okay.

Mal
 
Yes, it's either that and the filter is so darned inaccesible I couldn't say one way or the other or it may be another silly thing which you will see from my just-edited post
 
Since I have no detailed info on the engine, the following opinion may be of no consequence. /forums/images/graemlins/tongue.gif
The oil pressure transducer was the culprit of this type of mishap on some older engines. Especially the Volvo MD series, but others too, have oil senders which are constructed of a metal casing with a ceramic body inside. The fitting is more or less conical with a rough short tread. Very easy to overtighten, after which the sender is deformed. And starts leaks profusely when hot, through the gap between the ceramic center and the metal case.
As a local engineer told me, the oil under pressure can sometimes dump all the oil in less than 30 minutes.
 
Perhaps not relevant but I recently had to use a chain type grip to remove a filter, for various reasons I had to replace the old filter. The chain had made a small puncture on the back of the filter, oil was spraying out but hidden.
 
The Bukh DV20 and I expect the 24etc have a vacuum valve under the rocker cover. I have had to free this up by cleaning with petrol so that when you shake it it rattles. The effect I see when it is gummed up is oil leaking from the manual governor as this is mounted on a series of dished disk washers. The vacuum in the engine block pulls the assembly down and is sealed by the plastic washers underneath it. No vacuum no seal and oil leaking out from the assembly. Not a lot but enough to be annoying and require oil top ups.
 
One thing is for sure - the dealer has failed if he hasnt found the reason. I would be very disinclined to let them put the engine back in until they had established what happenend - they're the experts! Engines arent self healing!
 
[ QUOTE ]
I have a Bukh 23 on Kate. That has recently done the same thing. I've cleaned the oil out of the bilge, pumping it into a bottle via a small hand held pump. I refilled the engine and though it does lose a bit still I can't find where it came from.
I do have a LARGE spare can of oil on board now!

[/ QUOTE ]Common "fault" on the DV24 (haven't come across a 23) - check the oil pressure sender down the port side of the engine - failing that pull the flywheel and chank the counterweight cover. Those seem to be the two most common "overlooked" sources of oil leaks on the DV24s
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hammer.gif
Artificial Intelligence is no match for Natural Stupidity
 
I've covered the most obvious suspects, except for the drain plug, which is almost impossible to reach (if indeed there is one as the user manual describes changing oil via the dipstick hole and a pump). There didn't seem to be any sign of leakage around the filter but I did give it another quarter turn by hand, having changed the oil just pre-launch.

Of all the hassles I ever get aboard, most of them originate from engines and electricity. /forums/images/graemlins/confused.gif
 
I don't think my engine has that setup, as the manufacturers/yard haven't flagged that as a possibility and i can't see a mention of such in the users manual(which is modest in detailed information)
 
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