Oil Pressure variations

Discussion in 'Touring Models' started by Baldeagle1, Apr 30, 2011.

  1. Baldeagle1

    Baldeagle1 New Member

    Hi There,
    My bike, a 2003 Ultra Classic, suffers fom oil pressure variations.
    While riding at say 2000 - 3000 rpm the pressure can vary between say 26 to over 50 psi.
    So, one moment it low, and the next moment, e.g. after a short stop for a traffic light it can be up in the high 50 range.
    The oil level is correct.
    Can this hurt the engine and has anyone experienced this too?

    Many thanks,
  2. R_W_B

    R_W_B Senior Member

    I'm not an expert (they will hit here later) but I've heard that what you describe is normal with some Harleys. Mine seems to stay around 40 psi but I have a rocker panel gauge and I honestly don't look down at it much after I first crank up.

    My truck will sometimes drop to 30lbs at idle and then jump to 50 on take off.
  3. Breeze3at

    Breeze3at Well-Known Member

    Welcome to the forum. I have never seen warm oil pressure on my '07 as high as 50 psi. Mine stays between 34-40 above 2,000 rpm, and drops to nearly 0 at idle, (hot) which many others say theirs does. As soon as I get up to operating rpm again, the pressure comes back.

    BUBBIE Well-Known Member

    I would bet it is NOT any problem with the pump or by-pass spring in the oil system.... like Bereeze3at HINTS,,, Check your gauge First....There is the problem 90%....

    If your bike oil is Hot when it reads 50 It is one that is ABNORMAL if Not impossible..:coffee

  5. 89 FXRS

    89 FXRS Active Member

    I had a similar problem with strange readings, while on the freeway at 60-70 mph it would suddenly drop from 34psi to about 24psi then after awhile go back up - I hooked up a mechanical gauge and everything was fine - found out it was the sending unit that was bad - yours sounds like it could be the same problem - if it isn't the sending unit I would concider the gauge, the sending unit is easy to replace and doesn't cost that much, and the gauge is fairly inexpensive as well - fxrs
  6. R_W_B

    R_W_B Senior Member

    That must be why I've heard that most racing drivers prefer mechanical gauges over the electric analog or digital. They say they are more accurate with less deviation. Course you do have to pipe the oil itself to gauge which means you would not usually be able to put it on the handlebars but I know a guy who did it with soft 1/8" copper tubing.

    My Jerzee Customs mechanical gauge which I believe is manufactured by Edelbrock (which also owns Russell oil lines) always registers right at 40 psi or a little above that, everytime I have looked at it.
  7. 89 FXRS

    89 FXRS Active Member

    I used a piece of galvanized pipe,some fittings, and some hose, ran it up to the handle bars and zip tied it so I could read it while driving on the freeway at the speeds that I was concerned about - it wasn't very good looking as a matter of fact I did get a couple of strange looks while driving and trying to read it- but it did the trick - and actually from what I was told ,the mechanical gauge would be more acurate because the stock sending unit has to convert from the oil pressure to an electrical readout.
  8. big2wheeler

    big2wheeler Member

    I noticed my oil pressure doing that too. At start up (cold) pressure would be 34 at idle. After riding for a while when oil is hot the pressure would drop down to between 5 and 10. But at 2000 to 2500 rpm's it will go back to 34. It freaked me out at first, but I have been reading a lot on the internet from other sites that this is normal?
  9. Jack Klarich

    Jack Klarich Expert Member

    If in doubt you can make a master gauge to check against the stock gauge. They are notorious for being wrong:s
  10. kemo

    kemo R.I.P

    I would place my bet on a faulty oil pressure sending unit. We were talking yesterday about digital meters and mentioned that they break very easily, usually a cracked circuit board. Electric gauges are not digital but depend on many things such as a good ground and a good electrical connection. This is why I prefer a mechanical gauge.