crank case breather drips oil
simonm...@tiscali.co.uk
My BMC is rebuilt, back in the boat and I'm underway! However, I have a
little niggle which I intend to speak to the yard about on monday, but
I thought I'd get ng opinions.
The crank case breather is dripping oil intermittently, more so on
tickover. Too early to see just how much oil is being lost, but I'm
wondering why it's just started to happen.
The engine has just had a crankshaft/bearings/bearing shell overhaul,
plus a new oil pump. The engine is running very well since the
overhaul. Maybe these reground components have upset the balance
somewhere?
Cheers
Steve Atty
I assume that the engine oil level is good - overfilling could cause
excess oil splashing which could lead to oil getting up the crank case
breather. Also is the oil filler cap allowing the case to breathe?
Steve
Pete C
Hi Simon,
Good to hear the engine is up and running!
Where does the crank case breather come out? IIRC they should connect
to the air filter housing via a hose so that any escaping oil is
sucked into the engine and burned, so it's worth looking for any
unused hose connection on the air filter housing.
(See also last post here:)
<http://www.canaljunction.com/boat/engine_problems1.htm>
IIRC sometimes there is a metal mesh in the breather like that used
for those 'kettle descalers' which allows most of the oil 'spray' to
get caught and run back to the crankcase, if there is nothing like
this it might be worth checking if one was/should be fitted
originally.
It's definitely worth checking the oil level is not over full, also
wait to see if it was just some oil caught in the breather when the
engine was rebuilt.
Normally a tiny amount of gas escapes past the piston rings ('blow
by') and valve guides, and the breathers take care of this and stop
pressure building up inside the crankcase.
Something to try is to put a thin rag over the end of the breather or
oil filler when the engine is running, to see if it gets blown off
very easily, if it does then there's definitely some 'blow by'.
I suppose if the engine run out of oil the cylinder bores may have
glazed a little. I'd expect this could also cause some oil
consumption, if this is the case then someone on here mentioned that
Morris do a reasonable anti-glazing additive:
<http://www.morrislubricants.co.uk/productinfo.asp?v06c41q7p6=FMH>
Bear in mind that BMCs can have appalling levels of 'blow by' and
still function fine, but in these cases if the breather isn't
connected it'll coat the engine and it's surroundings with oil!
BTW how much was the regrind and new shells if you don't mind me
asking? It's also probably worth finding out how best to 'run in' the
new bearings...
cheers,
Pete.
Martin Phillips
<pete...@gmail.com> writes
>
>Where does the crank case breather come out? IIRC they should connect
>to the air filter housing via a hose so that any escaping oil is
>sucked into the engine and burned, so it's worth looking for any
>unused hose connection on the air filter housing.
My old BMC didn't have a connection on the air filter housing, so I made
one from a brass tank connector with a stub of 15 mm pipe on it, and a
length of rubber hose going to the breather outlet tube.
>Bear in mind that BMCs can have appalling levels of 'blow by' and
>still function fine, but in these cases if the breather isn't
>connected it'll coat the engine and it's surroundings with oil!
My old BMC had a huge amount of gas coming out of the breather for years
(and getting into the coolant). It had what engine men call a "porous"
block. It took about 1500 hours of hard running before it eventually
died.
Wassail!
--
Martin E Phillips nb Boden, Splatt Bridge
http://www.g4cio.demon.co.uk martin/at/g4cio/dot/demon/dot/co/dot/uk
Homebrewing, black pudding, boats, morris dancing, ham radio and more!
The Gloucester-Sharpness canal page http://www.glos-sharpness.org.uk
Brian
"Martin Phillips" <mar...@nospam.com> wrote in message
news:MZZqhOF6...@g4cio.demon.co.uk...
> In message <h40tb1t4v9h7ohlg9...@4ax.com>, Pete C
> <pete...@gmail.com> writes
>>
>>Where does the crank case breather come out? IIRC they should connect
>>to the air filter housing via a hose so that any escaping oil is
>>sucked into the engine and burned, so it's worth looking for any
>>unused hose connection on the air filter housing.
>
> My old BMC didn't have a connection on the air filter housing, so I made
> one from a brass tank connector with a stub of 15 mm pipe on it, and a
> length of rubber hose going to the breather outlet tube.
>
>>Bear in mind that BMCs can have appalling levels of 'blow by' and
>>still function fine, but in these cases if the breather isn't
>>connected it'll coat the engine and it's surroundings with oil!
>
> My old BMC had a huge amount of gas coming out of the breather for years
> (and getting into the coolant). It had what engine men call a "porous"
> block. It took about 1500 hours of hard running before it eventually died.
>
I have heard it said and I'm sure Tony will soon be here to say otherwise
that when you overhaul the bottom end of an engine you get more oil up to
the rocker gear and if you have gas blowing passed the piston rings/valve
stems you can blow it out of the top with some oil.
--
Brian Ancient Order of Sewer Ants
Drifter
Martin Phillips wrote:
> In message <h40tb1t4v9h7ohlg9...@4ax.com>, Pete C
> <pete...@gmail.com> writes
> >
> >Where does the crank case breather come out? IIRC they should connect
> >to the air filter housing via a hose so that any escaping oil is
> >sucked into the engine and burned, so it's worth looking for any
> >unused hose connection on the air filter housing.
>
> My old BMC didn't have a connection on the air filter housing, so I made
> one from a brass tank connector with a stub of 15 mm pipe on it, and a
> length of rubber hose going to the breather outlet tube.
I've just done this on our old VW T25 Campervan. The 1600 diesel engine
has gone round the clock one and a half times, and the sump was
pressurising, badly affecting what little performance there was.
We were touring bits of Cornwall, Devon, Somerset and Wiltshire last
week. The van just didn't like the hills until I bought £3 of washing
machine waste hose and a couple of jubilee clips. I replaced the
existing, obviously blocked vent hose and fed the new hose straight
into the air intake.
The engine was rejuvenated. Don't see why it shouldn't work on a boat
too.
Tony H
giving vent on the Basy
Drifter
Drifter
Glad you're back on the move, Simon! We'll be engineless for another
three or four weeks, yet. Not that we can get far anyway until the Basy
is reopened.
It does sound like your sump is pressurising somewhat. Did the yard
carry out compression checks while they had the engine out?
It isn't a terminal problem, though.
See my response to fitting a vent pipe back to the air intake. But if
oil is persistantly being blown out of the breather, you may have to
incorporate an oil trap too. Did this many years ago on an old Standard
Vanguard by hanging a small can under the breather pipe. After each
longish journey I used to strain any accumulated oil, and pour it back
into the sump!
Waste not want not.
Tony H
oil be blowed... still on the Basy!
bro...@reading-college.ac.uk
chamber.
We often joke about BMC comming complete with Factory Fitted Oil Leaks
and those 1.5 breathers are a major cause.
To be honest not pulling the pistons, glaze busting the bores and at
least fitting new rings sounds liek a job on the cheap to me, but I
know we sometimes have to settle for what we are forced to afford.
As the engine has be all and every way up I would wait a while to see
if the drip stops.
On the fleet we drilled and tapped the inlet manifold, inserted a pipe
connector and connected the breather straight to that, however I
suppose it does increase the risk of a runaway somewhat.
The 1.8 may have a gauze oiltrap in its tappet cover so visiting scrap
yards who specialise in older vehicles may pay dividends. I think any
side/tappet/cam follower cover off any BMC/Leyland 1.5/1.6/1.8 petrol
or diesel engine woudl fit, so its just a cas eof finding one with an
inbuilt oil trap. but please make sure its claen before fitting.
Tony Brooks
simonm...@tiscali.co.uk
Thanks for your responses.
Did 6 hours yesterday, lost about a quarter of a litre.
Did 8 hours today, doesn't look like I've lost any oil. Think I will
put a bowl underneath and recycle whatever I can!
The top end was not overhauled because a) Money and b) The compression
test was fine.
Just learning to live with the BMC oil monster!
By the way, I'm up as far as Bourne End. Oxford Friday, Lechlade Sunday
night.
Bye all
Drifter
simonm...@tiscali.co.uk wrote:
> Hi all,
>
> Thanks for your responses.
>
> Did 6 hours yesterday, lost about a quarter of a litre.
>
> Did 8 hours today, doesn't look like I've lost any oil. Think I will
> put a bowl underneath and recycle whatever I can!
>
> The top end was not overhauled because a) Money and b) The compression
> test was fine.
>
> Just learning to live with the BMC oil monster!
>
> By the way, I'm up as far as Bourne End. Oxford Friday, Lechlade Sunday
> night.
>
Quarter of a litre?????
You call that an oil leak?????
We lost 10 litres in about 6 hours!!!!!!
Just baled it out of the bilge.... which is considerably easier than it
sounds... with the engine about 10 miles away atcf
Anyone wanna buy any old oil [mixed with dirty water]?
Tony H
off to an official waste dump near the Basy
Tony H
Neil Arlidge
Go on Simon..have a go above Lechlade! ;-)
--
Neil Arlidge - NB Earnest
Follow the travels of the TNC at : http://www.tuesdaynightclub.co.uk
simonm...@tiscali.co.uk
back in Oxford next wed. It looked tempting last time I was there
though.
I'm in Goring this evening, the mooring is now owned by Yuri Geller of
all people, fiver a night, maybe I'll just bend some spoons and put
them in the payment box.
Cheers
Simon M
http://www.narrowboat-havana.co.uk