Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Oils aint Oils soul!!!

Discussion in 'Technical and Troubleshooting Torque' at netrider.net.au started by Caz V1, Jul 10, 2007.

  1. Something strange has happened.........
    my bike had a slight oil leak, used to run down the side stand and every morning there would be a few drops on the garage floor.
    Last month I did an oil change but changed to Motul oil from yamalube....
    and now I have no oil leak..... how can this be?


     
     Top
  2. Thicker oil not seeping past the gasket which has the leak in it.

    The thinner the oil the better it gets into the nooks and crannies in the engine and gearbox but also the easier to finds it's way out of the engine as well :roll:
     
     Top
  3. Or you've leaked that much oil there ain't none left!
     
     Top
  4. Different oils, or for that matter just replacing a clogged oil filter with a clean one, can also affect the oil pressure - and this can have a big affect on whether oil seals leak or not.
     
     Top
  5. Different oils have different additives in them. It can be the other way around and after changing brands leaks appear.
     
     Top
  6. also old oil is thinner, particularly in bikes where it must endure the shear stress associated with gearboxes.

    someone also had a theory that synthetic oils get past some gaskets that mineral oils don't. Not sure about that one.
     
     Top

  7. lol, I have got blonde streaks but I'm not daft :p
    I checked the sight glass this morning, all is good. :)
     
     Top
  8. Every brand of oils makes different viscosity oils, perhaps you have selected a higher viscosity oil from the motul range. Also, Usually as oils become "worn" they can thin out.

    Regardless I think that it will only be a matter of time before your oil leak returns. For oil to have been leaking, you likely have a faulty seal, they rarely fix them selves.


    One additional thing to check, and this has caught me out once. Ensure that you crank case breathers are not blocked as it will cause a pressure build up in the crankcase. Oil seal are the next easiest way for the pressure to release. This particular situation would not likely have oil leaking out overnight though.
     
     Top
  9. See Caz, what Sobil said.. :p
     
     Top
  10. What they all said. Motul is good chit Caz, I always run it and aint got no complaints :grin: It definitely seems to prolong engine life for money :wink:
     
     Top
  11. this oil leak down the side stand are you sure its not chain lube? form the front sprocket?
     
     Top
  12. Also some oils have seal swell additives which can affect the rubber of seals, causing them to swell and take up the gap properly, stopping the leak.

    Your old oil also probably contained some condensed petroleum vapours too, which would thin it out and shrink the seals.

    but +1 to the sprocket lube theory also..
     
     Top
  13. Had a similar problem, turned out to be chain lube from a new chain sprokets etc. It does not hold anywhere as much oil as the old chain and i guess i have been putting a bit too much on. Anyway it leaked for a little right ar the front sproket and then stopped. have kept and eye on it any way, it also had an oil change at the same time.
     
     Top
  14. hey Caz, can you humour an old guy and edit the thread title to "Oils ain't oils, SOL", that's the line from the original GTX advert??? :).
     
     Top
  15. OHHH! now I get it.
     
     Top