Not Sure If New Oil Temp Gauge Is Working Right

Discussion in 'Oil' started by Dr. Dolittle, Feb 22, 2009.

  1. Dr. Dolittle

    Dr. Dolittle Experienced Member Staff Member Moderator Contributor

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    Swapped the air temp gauge in my fairing for an oil temp gauge and I'm not sure if it's working normally. Some things I've noticed:

    1) Takes a good 10 or 15 minutes of riding before the temperature comes up off the 110 mark (lowest temp on the gauge)
    2) Vast majority of the time in the last 2 days of riding (since new gauge installed) it runs about 190 degrees. This seems about right to me. However, sometimes I look down and it's at 230 to 240 for a couple minutes, then drops right back down to 190
    3) Today I was at a steady speed turning 3000RPM and the gauge read around 250 or 260 for a couple minutes! Then right back to 190
    4) Sitting at a stoplight at idle, I just happened to be looking at the gauge when I squeezed the front brake lever and it jumped from 190 to 230 and dropped back to 190 when I released the brake lever. Did this twice and then I couldn't get it to do it again with front or rear brake.

    I guess I should add that the outside air temp was mid 40's to mid 50's both days, good oil quantity, no other symptoms at all.

    Anyone have any opinions? Normal or no? Did anyone else have similar symptoms? How did you correct them short of replacing the gauge or sending unit?

    Bike's running fine but I'd sure like a fully functional oil temp gauge.
     
  2. kemo

    kemo R.I.P

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    It seems to me that it is reading erratic. Mine takes about 10 miles to get to 170. Running hiway at 70 it is about 220 on a 65# degree day. Stopped in traffic about 250 or higher depending on air temp and lenght of time, I have seen it at 235 cruising on a 70 -75 day. I think you might have a bad temp sender or maybe a pinched wire, but I would think if the wire was pinched the guage would peg itself to the high side of the guage. What guage do you have Harley or McEwen. Mine is the McEwen
     
  3. porkchop

    porkchop Active Member

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    You have a ground problem. Check the ground strap for the engine to frame for rust or corrosion. check ground from batt to frame/engine, gauges ect. Let me know what you find.
     
  4. kemo

    kemo R.I.P

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    Did you wrap the sender with teflon tape. If so that can be your problem
     
  5. Dr. Dolittle

    Dr. Dolittle Experienced Member Staff Member Moderator Contributor

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    The gauge is the HD one. The temps just seem to jump even when the riding conditions do not change.

    Only a 1 year old bike with no rust anywhere. All other gauges and functions operate perfectly. I'll check but I doubt if this is it.


    I felt like this project was a bit over my head so I had my indy mechanic do it. Can I see this visually or will I have to call him to check?
     
  6. kemo

    kemo R.I.P

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    If he installed the sender in the oil pan you most likely would see some white tap strands around the pipe fittings. If he taped the fittings it can prevent the unit from grounding.
     
  7. glider

    glider Veteran Member

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    Easiest way to check it is with a piece of wire or a screwdriver by making a connection between the case of the sender and to the ground of the engine and see if the temp gauge registers properly.
     
  8. porkchop

    porkchop Active Member

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    Age doesnt matter. A grounding issue could come up at any time. When the indy guy had your dash apart he could have not got it grounded good on the install. On the back of the gauge there are two wires, one is power the other is ground that goes strait to the sending unit, inturn the sender is completeing the circut with resistance. You can unplug the wire off the sender and ground it out on the engine or frame and the gauge should peg out at high, this can help narrow it down a little.
     
  9. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    The 190* seems OK for your conditions. As Kemo says, the sending unit SHOULD NOT be wrapped in teflon tape when installing. You can crawl down their as much as you can to get an eyeball on the sending unit. Should be at the front bottom of the oil pan. Try to see if there is any teflon tape protruding from where the brass fitting goes into the tank. If you can't see any, call the guy and ask him. He may not remember.

    1. If there is teflon there, the plug will have to come out (drain the oil first!!!) and the teflon removed from the threads on the plug AND the hole in the oil pan. Reinstall with NO teflon. It is a pipe thread and should get tight enough to seal.

    2. If that is not it, check the plug that goes on the sending unit to make sure there is a good interference fit when you plug it on. You may need to crimp the plug sides a little so there is GOOD contact when you plug it back on the sending unit.

    3. If all that is done and it is STILL messing up, pull the fairing and make sure the wires plugged into the back of the gage are all tight. May have to do the "tightening" work like above to make sure there is good contact when you plug them back on.

    4. If none of that works, BAD GAGE or sending unit. Have to send it back and get a replacement.

    Number 2. above is the easiest after spying to see if there is teflon tape. If there is teflon, fix that.

    At this time of year, it is taking me until I am almost at work (about 30 min. and 20 miles of mixed riding) for my oil temp to start getting around 170-185*. Air temps have been in the 40s on the way to work.

    Good luck.

    TQ
     
  10. Dr. Dolittle

    Dr. Dolittle Experienced Member Staff Member Moderator Contributor

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    Man, you guys are the greatest! I went out and eyeballed it and there does seem to be some material where the sending unit screws in - by the way, for a 2008 it goes on an adapter on the oil filter, not in the oil pan. I will remove this material first and then proceed with the other tests everyone suggested. I'll do the inside the fairing stuff last - probably wait for my new Clearview shield to arrive and do it then if the other things don't clear up the problem.