How to test custom oil pressure gauge

Discussion in 'Softail Models' started by Piotra, Apr 9, 2011.

  1. Piotra

    Piotra Active Member

    106
    26
    0
    Hello
    After the winter I started bike today. The engine was working like few months ago before winter. It wasn't going too hot, just seemed that all is OK. But I noticed that I have no oil pressure on the gauge. I have this type an oil pressure gauge by V-twin:

    [​IMG]

    I have it mounted in this place where should be oil sensor but I have no sensor installed - just gauge. Before winter there were oil pressure on the gauge and now there is no. So I think that maybe just gauge is broken. I check oil screen and there is oil and the oil screen is also clean. It seems that the glycerin is in gauge. But I can only say that it seems because I remember that before there was an air bubble in gauge, now there is no air bubble. I do not know why.

    So I think that maybe tomorrow I will remove the gauge and will install oil sensor. Can you tell me how can I connect this oil sensor just for checking oil pressure. I didn’t use it before so I do not have light indicator. Can I just take 12V light bulb and connect from one side to oil sensor and from the second just to the + on battery. Just for testing not for riding?

    Or maybe can you give me other advices how to test oil pressure and this oil gauge. I think that oil is going through oil lines because after few minutes of engine work I can see some air bubbles in the oil inside the oil tank and the temperature of oil (I have an temperature gauge on dipstick) risen a little bit.
     
  2. Jack Klarich

    Jack Klarich Expert Member Contributor

    17,340
    123
    125
    You could buy a cheap gauge with plastic line to test for oil pressure, if you have no knocking and your filter is full it would seem you have pressure but I would check for sure. Gauges have been known to fail:s
     
  3. Piotra

    Piotra Active Member

    106
    26
    0
    What kind of cheap gauge, can you show on picture? This V-Twin gauge was cheap and I hope that this is a problem. It costed about $30. Are there cheaper gauges???
     
  4. Piotra

    Piotra Active Member

    106
    26
    0
    Hello
    Today I took first ride on my bike. I finish building last year but getting license plates for custom bike took a little bit time (I got it in winter). So today I had first ride !!! It was exciting, the motorcycle ride great but I check how this pressure gauge is working and this is what I observed.

    When I start engine and I have choke the oil pressure gauge is showing about 30 lbs, after few minutes when the engine is a little bit warm and choke is off, the bike is idling and pressure is between 10-20 lbs. When I accelerate (without riding) the pressure is above 20 lbs. Than I take a ride, at the beginning all is OK, but after about 2 miles the pressure on the oil gauge is 0 !!!! When I accelerate is still 0 !!! The indicating needle is not moving. The engine is working OK. When opened the oil tank I can see that oil is warm (after about 6 miles the oil temperature gauge is showing 75-100 F). I can also see in the tank that oil is flowing to the tank. When I’m looking into tank and accelerate I can see that more oil (and faster) is flowing to the tank.

    So what do you think? Is it the problem with oil pressure gauge or with oil system? But I think that if the oil pump would be broken it would not work all the time, also after starting cold engine. I’m using RevTech mineral oil 20W50 (the engine is also RevTech). I do not think also that when the engine is cold the oil viscosity is large and after few miles when the oil temperature is 75-100 F the viscosity is small.

    Please give me some advices. I do not want to buy new gauge if it can be any other problem.
     
  5. R_W_B

    R_W_B Senior Member

    2,425
    0
    23
    I think the first thing I would do is go to Harbor Freight and buy an Oil Pressure gauge on a rubber hose (like Jack said) and test to see if your pressure at idle matches your gauge. I think they were $12 when I bought mine. If it does not match your gauge, then something is probably wrong in the gauge area. To make sure you could then plug the temp gauge up on your car and see if it matches there (just to test the temp gauge).

    You could just install the OEM sensor back in but those things really only lite up when the pressure drops below 5 lbs and there is no garauntee that it is still working.

    I'm not sure what to say about the readings all over the place like that. Do you have an oil cooler with a thermostat on it? I've heard of pressure dropping temporarily with those. I had the oil pump go bad in my Truck and it just showed 15 lbs on the gauge all the time (instead of the normal 45+).

    I have a Jerzee Customs oil pressure gauge (mechanical type) on my bike and it shows 45lbs pressure every time I look at it. It may drop when my oil cooler kicks in but I've never look down in time to notice.

    Maybe someone with more experience in oil related issues will see your post.
     
  6. Dr. Dolittle

    Dr. Dolittle Experienced Member Staff Member Moderator Contributor

    6,392
    98
    17
    I wonder if they have a Harbor Freight in Poland? :s
     
  7. Piotra

    Piotra Active Member

    106
    26
    0
    No, we have not Harbor Freight in Poland :(
    Can you give a link to any picture showing this oil pressure gauge on a rubber hose? When I will see how it look like maybe I will find it in other shop.


    For R_W_B:
    I have an oil cooler but without termostat, just this type which is following frame at front:

    [​IMG]
     
  8. JBC2565

    JBC2565 Junior Member

    582
    28
    2
  9. Jack Klarich

    Jack Klarich Expert Member Contributor

    17,340
    123
    125
    A manual gauge off a heavy duty truck or tractor could be adapted to check the pressure. I use an old MACK diesel gauge with a bushing and a grease gun hose very easy to use and fits nice in tight places:s
     
  10. R_W_B

    R_W_B Senior Member

    2,425
    0
    23
    Oh jeez guy I'm sorry I didn't notice you were in Poland. I'm sure they have the equivalent tester though at one of your discount parts dealers. If you don't have a thermostat in your oil cooler then I doubt it would be the case of your pressure dropping. And even then it should only drop momentarily. It sounds like you have a bad gauge. I would get this fixed though, and until you do I would hook the wire back up to the oil lite sensor. That way it will come on if you had a severe drop in pressure and at least tell you that you need to shut your engine down.