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Oil Light down hill decent

Discussion in 'Norton Motorcycles (Modern)' started by pingu-nz, Feb 9, 2019.

  1. pingu-nz

    pingu-nz

    Joined:
    Jun 24, 2011
    Has anyone else had the oil light come on whist riding down a mountain road ??

    We have a Mt Tamborine which I ride most weekends and the decent is a good 2 kms down hill .
    This is steep enough that the oil light will come on and the engine noticeably gets a rattle in the top end.
    Last 2 times I have actually turned engine off and coasted down hill.

    My oil level is full on the dipstick .

    Thoughts ???
     
  2. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Hi Pingu, I’ve not had this so can’t really help you.

    I would like to point out though that the oil light is a low pressure warning, not low level. And the handbook says the usual ‘stop th EE fine immediately otherwise extensive damage could occur.

    So, I’d take it seriously if it were mine.

    Usually, the first thing to check at times like this is the oil pressure switch itself. Unless you’ve got fancy equipment, the easiest way to do this is by swapping it for a new one and seeing if the symptoms persist.

    Good luck !
     
  3. kommando

    kommando

    Joined:
    May 7, 2005
    Reminds me of the issues the Police had with SD1's/Range Rovers fitted with V8 engines, when they sat on the top of downward inclines on motorway on ramps waiting for a speeding car to chase with the engine running, in this position the oil was away from the oil pickup and not circulating. Cue one blown engine when they rapidly accelerated to join the chase. Odd for similar symptoms to be on a dry sump engine though.
     
  4. TonyA

    TonyA VIP MEMBER

    Joined:
    Jan 16, 2015
    Maybe not odd . If the incline is steep enough , front end pointing downward . The oil pickup is at the back of the frame oil tank . What if the incline is so STEEP that the oil is pushed completely to the front and leaves little for the supply line ??? ADD MORE OIL and try again I say . You need to keep that oil feed covered with oil ! Just how steep is it - Very steep I'd say and on the brakes too. If you're running the new lowered mark oil stick you can raise the oil level to the original full mark (about 25 mm higher on the stick) . I thought you sold your bike for a CNW .?
     
    Last edited: Feb 10, 2019
    contours likes this.
  5. pingu-nz

    pingu-nz

    Joined:
    Jun 24, 2011
    I still have my bike Tony
    20000 km on it now
    The 2 hill decents are a 18%
    And yes I think the oil is forward in the tank enough that the oil is not reaching the rear of the tank .
    runs fine up hill and around the flats.
    maybe its time to try a oil line mod.
    tee off the return line above the oil cooler direct to the pump feed line , then any excess oil can return to tank. this should effectively give me a pressurised oil feed direct back to the pump, but any excess will return to the tank .

    something to think about

    cheers
    Paul
     
  6. Voodooo

    Voodooo VIP MEMBER

    Joined:
    Aug 10, 2016
  7. pingu-nz

    pingu-nz

    Joined:
    Jun 24, 2011
    wow ,interesting read glad you got it sorted .
    my light only comes on for the downhill grade,
    on level ground and uphill there are no problems .
    as tony said downhill with a bit of brakes forces the oil away from the pump feed ,
    if I add more oil it blows it out into the catch bottle through the breather,

    catch 22 situation

    cheers
    Paul
     
  8. Voodooo

    Voodooo VIP MEMBER

    Joined:
    Aug 10, 2016
    You need to manually check the oil pressure with a gauge or have it checked. It only takes a few minutes and will pin point the cause before it’s to late.
     
  9. TonyA

    TonyA VIP MEMBER

    Joined:
    Jan 16, 2015
    Check the oil pressure first . But If you find that the steep desents are starving the oil feed you can add a reservoir of oil . This would be put where the in-line filter screen is on the feed side essentially . A canister of oil in line with the filter screen . This would bridge the sarvation gaps until the canister runs out. Hopefully by then you have gotten to the end of the extreem desent . The reservoir canister would not effect the oil level in the frame oil tank and it will add capacity to the system . IMG_E3236[1].JPG
     
    Last edited: Feb 11, 2019
  10. Voodooo

    Voodooo VIP MEMBER

    Joined:
    Aug 10, 2016
    What year is your bike?
    What length of dip stick do you have?
    (Never thought I’d ask another man that)
     
    TonyA likes this.
  11. Voodooo

    Voodooo VIP MEMBER

    Joined:
    Aug 10, 2016
  12. TonyA

    TonyA VIP MEMBER

    Joined:
    Jan 16, 2015
    Hello Paul , Can you send photos of this steep decline ? Thanks .
     
  13. pingu-nz

    pingu-nz

    Joined:
    Jun 24, 2011
    geesh, tony its been a while since I posted a photo let me have a play around
     
    TonyA likes this.
  14. pingu-nz

    pingu-nz

    Joined:
    Jun 24, 2011
    here it is tony Mystery rd

    [​IMG]

    [​IMG]

    here is another thought , send oil straight from cooler to supply hose ,but install reduced tee to redirect excess oil to tank .
    [​IMG]
     
    Last edited: Feb 11, 2019
  15. TonyA

    TonyA VIP MEMBER

    Joined:
    Jan 16, 2015
    Will the reduced tee favor the oil pump feed side or the oil tank ? I was just concerened that I would be bypassing the oil tank entirely. I would monitor not just the oil pressure but the oil temp as well if you can somhow after doing this . As a test , have you tried to add more oil to the original upper level , just to see if that stops your issue ? Great picture , thanks for posting.
     
  16. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Pingu,

    I think you idea may cause problems. You may confuse the flow of oil.

    The oil will always take the path of least resistance.

    So, you can end up with some oil circulating around your loop constantly and some oil staying put in the oil tank.

    The oil tank is an important part of the oil cooling process.

    So the oil in the ‘closed loop’ will get a very hard life.

    The only way I can see your idea working is to instal some kind of ‘injector tee’.

    This is a tee that uses the Venturi principle to pull fluid through the other part of the tee.

    It could be used to create your loop whilst also pulling oil from the tank and into circulation.

    But personally I would be quite nervous of playing around with the oil circuit in this way.
     
  17. Fast Eddie

    Fast Eddie VIP MEMBER

    Joined:
    Oct 4, 2013
    Circuits like this rely on having a ‘neutral point’ somewhere in the system. This is the point where the fluid stops being pushed by the pump and starts being pulled by the pump.

    When you insert extra tees as you have shown, you mess with this neutral point.

    So, things may happen to the flow that you did not intend / expect.

    Hence, unless you really know what you’re doing here, and can simulate and trial your ideas, I would be nervous...
     
    jbruney likes this.
  18. pingu-nz

    pingu-nz

    Joined:
    Jun 24, 2011
    What would be the ratio of the pressure side of the pump to the scavenge side of the pump ?

    The pump only relies on gravity feed for the intake side or does it pull oil? however when the engine starts the scavenge side of the pump pushes much more oil back to the tank, with the cap off the flow back to the tank is very strong.

    looking at the diagram , The oil should still enter the tank as well as supply the intake line as there is quite a bit more pressure from the scavenge side, may be if I had a reservoir on the supply side this would accumulate more oil for pump on downhill rides .

    Most of my riding is on flat ground but I have 4 options for going up and down Mt Tamborine and on all options I have the oil light flicker and come on whist descending.
    I think I will fit a oil pressure gauge whist trying any changes.
    all changes can be reversed if needed .

    Thoughts
    cheers
    Paul
     
  19. pingu-nz

    pingu-nz

    Joined:
    Jun 24, 2011
    Tony

    if I add more oil it will be blown out the breather
    the reduced tee could favour the tank side so the oil can pass direct to the supply side and the excess can return to the tank.

    What if the hose that bypassed the oil tank was 1/4 " and the maim hose to and from tank remained 3/8" this would let a smaller amount of oil direct to the pump intake but the extra would still go via the tank ?

    I will be installing a pressure gauge to monitor the oil and all modifications can be reversed .
    I more want to trial mod to see if it fixes the downhill oil starvation issue
     
    Last edited: Feb 11, 2019
  20. pingu-nz

    pingu-nz

    Joined:
    Jun 24, 2011
    riding down one of those hills :)

    [​IMG]
     
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