Oil Leaks

[Tapitha]

The article about oil leaks in the latest "Minor Matters" states that "........ any leak is usually down to the crank breather system blocking and this is very easy to clear." My question is what and where is the crank breather system and how do you clear the blockage?
Mike

[les]

It's the crankcase breather system, and the blockage can be in the pipes or the canister, which is what you can clean out.( fitted to the side of the engine or possibly at the front, on the timing chain cover) The accompanying article to the right of the piece you read is carrying out this procedure. Some engines don't have this system and rely on a metal pipe going directly to the atmosphere, it doesn't usually block but can be cleaned out, if you have a pipe coming from the rocker cover that should be clear.

[bmcecosse]

Hahahaha. Who writes these articles? Are they cribbing directly from the Forum ??

[Budgie]

I have the same problem and today I finally got around to trying to sort it out and following the advice from the good folk on here I removed the breather canister and although it seemed relatively clear I power washed it, flushed it with solvent and finally blew it through with an air gun! So my question now is how long should I wait to see any results as it was still weeping after all this attention all be it while she was idling shortly after the treatment. I'm told it can take some time before things settle down if my attempts are fruitful.

[bmcecosse]

And is the can connected to the intake system in some way? Where are the leaks - if down the front/back of the sump - then look to new gaskets and cork seals. If from the timing cover seal - new seal. If from the cam follower covers - new gaskets and rubber seals under the bolt heads. If from the rocker cover (and running down...) then obvious remedy.. If dripping from the gearbox jiggle pin - then this is caused by pressure in the crankcase (and possibly worn main bearings...) and depends on good engine condition - and good crankcase breathing.

[Budgie]

It's a classic crankcase weep so dripping down by the gearbox and off the sump lip and jiggle pin. The can is connected to the air intake via a rubber pipe which is clear and so is the air filter, there was a small amount of sludge in the canister but nothing to write home about and it did blow fairly clear when I puckered my lips to it before I thoroughly cleaned it.

[bmcecosse]

The later SU carb with the side vent pipe is better, and the PCValve as fitted later engines is best of all. How does the engine fare in the 'fume' test ?

[Budgie]

As in "exhaust fumes" ? btw my tourer is a 1969 model if this makes any difference.

[bmcecosse]

No no - engine hot and idling - remove the oil filler cap and rev up - is there a plume of fume/smoke ?

[Budgie]

Ah right no all's well in that department.

[bmcecosse]

So I'm afraid you need to suspect worn rear main bearing....

[mike.perry]

Do not park on your friend's newly laid block paved driveway

[Budgie]

So I need to see a plume of smoke / fumes when I rev from the oil filler cap when the engines warm? I thought that would mean problems not vice versa!

[panky]

No if there is a plume of fumes it would suggest that the rings are worn leading to the crankcase being pressurised and causing the oil to leak passed the crankshaft end. If that's not the case then that's one thing eliminated.

[Budgie]

Ah right I understand now.....got me worried for a minute!

[bmcecosse]

What's the oil pressure like? You may just have to live with the problem - if you are SURE the oil is coming from the jiggle pin. Wipe everything down really well - then wait and see. If the breathers were choked - there may be oil in there which will still need to drip out - and then hopefully it will dry up ... Fingers crossed !

[Budgie]

I was told by my brother in law that it may take some time to settle down as he seems to think it's the classic crank case oil leak he was the one that helped me clean the bits out and checked the leak as the engine was running and has seen this many times over the years so like you said ..fingers crossed, watch this space as I shall update if things turn out positive!