Morris Minor Owners Club

hi i have problems with engine oil leaking between the engine and gearbox. I heard that this is common? Can i solve it as i have to top up about 1litre every couple of month in order to be in a required level.
Please advice. Thanks

Jason, start off by cleaning out your breathers and making sure that your breather hoses are correctly installed. Then, with warm engine running, remove oil filler cap and see if you get any smoke coming out. The oil leak is either a sign of blocked breathers or a worn engine.

Where is this Breather? Is it the one from the rocker cover to the carb filter assembly? How can i clean it?

And yes smoke does come out of the ends of the breather hose and when i open the oil filler cap it happens too.

Should the breather pipes be tightened to the rocker cover and air filter assembly by a cable tie or should it just be sleeved on?


FYI: I would also like to add that oil leaks most, when the car is parked and engined turned off.

Only really a bad sign if there is a LOT of fume/smoke coming out with the oil filler cap off - when you rev up the engine!

Yes, the breather is from rocker cover to carb. Take off the rocker cover and you should see a baffle plate where the breather is - Make sure this is clean and also the pipe is not gunged up. Pipes should just push on. Depending on your engine there may be other breathers and if not, it may be possible to fit another from the timing chain cover etc.

Best way to prevent oil leaks is to arrange a slight negative pressure in the crankcase. the later SU carbs have a pipe on the side which takes the engine fumes directly from the rocker cover into the inlet manifold. This is FAR better than the earlier system where the rocker breather connected to the air filter - and simply covered the paper element in oily fumes, soon choking it solid!

This is my setup.

When engine is warm, i open the oil filler cap, there are fumes coming out. Did what Roy says to rev up and there are no fumes. Suggestions?

Roy you are saying connect to the inlet manifold from the rocker cover. My inlet manifold does seem to have that but it is currently connected to the brake servo. So do you suggest i connect it to the inlet manifold instead?<br><br>

No, don't touch the servo pipe.
Is there another (blocked off) connection on the manifold? How about on the carb, towards the manifold side?

The breather needs a fairly narrow connection to the manifold to work properly, if you connected it directly to a 12mm pipe it would seriously mess up the fuel/air mixture. The servo, however, needs to see the full manifold vacuum so has a wider pipe.

If you could post a photo of the other side of the carb that might help.

If there is no 'cloud of fume' when you rev up - it's not too bad! Your engine has the earlier arrangement with the breather going into the air filter casing - this plasters oil all over the filter (soon blocking it!) and doesn't give much 'suck' on the crankcase. The later carb has a brass pipe connection on the side, to which the breather connects - and this draws the fumes/pressure away very much better - and without ruining the air filter. Look for a later type carb!

My new 'donor' engine has the breather coming from the tappet cover via a gismo (which I dont have) ending up in the later model carb you mention. The old engine has it from the rocker cover. straight into the air filter.
?which do I use? do I need to find the gizmo or can I fit straight from the tappet cover into the 'new' carb

Throw away the gizmo - just connect directly from rocker cover to carb side inlet - and let the cam follower breather hang free!