Showing Oil Pressure When Engine Cold and Not Running

Question

I noticed a strange problem on my motorcycle last night.

I have a 2006 ZX-10R and as I was leaving work, I noticed the oil pressure warning was not on. Normally, as soon as you turn the key to the on position the oil symbol and FI light will blink to indicate there is no oil pressure. This makes sense as the engine isn't running yet. However, last night the symbol and light were gone, as if there was pressure, even without the engine running. The bike had been sitting all day and was at ambient temperature.

I had no reason to suspect that there was actually a problem with the oil pressure in the engine, so I drove home. Upon arrival, I hit the kill switch and noticed the oil pressure light was working fine again. The symbol appeared and light flashed as the engine stopped and pressure dropped.

This morning, I left for work and same thing again. It didn't work when I left my house, but worked fine by the time I got to the office.

I'm hoping this is just a bad sensor, but the fact that it works on and off depending on engine temperature seems strange to me. If it was broken I would expect it not to connect at all and always show no oil pressure.

Any ideas if this is a common or likely issue, or what else would cause this sort of problem?

Answer 1

You could be correct with a bad sensor, or possibly, a corroded connection (vibration making the contact) or a broken wire or a faulty contact in the ignition switch. That's the fun (!!) with electrical faults . tracking them down.

Answer 2

When you start most vehicles and motorcycles are not an exception to this, all of the display lights are lit indicate that they are all working. If something is not "ON" then it's very possible that the bulb is burned out or a poor connection to the bulb in the panel. Once the vehicle is running all of those lights go to their final state.

This is done so that you know you can trust that all of the lights are functional. Should your oil pressure actually go low that the light would be on. With its current state you will not receive notification the oil pressure is low if it were to be so

Edit: I somehow missed that it was temperature related. In that case the bulb is good and you have a wiring problem. I wouldn't suspect sensor first. However I would suspect the wiring to the sensor since that is where the heat is going to happen first.

An interesting test for you would be for you to try to start it and wait til the engine reaches temperature without haven't gone anywhere. Then you will eliminate most vibration of driving and narrow it down to a temperature related issue.

Temperature related wiring issues are the worst to track down and you may also just end up putting a continuity meters across things sections of the circuit and wiggling the wires to see if your continuity goes away. Either audible or light will work for that but you want something obvious and not just a meter reading.

If you have a nine volt battery and a Christmas tree light not one of the LED kind you can fashion yourself a cheap test circuit with that and a couple of lengths of wire you want to have it so that you touch the wire to two parts of the circuit and then the light bulb will come on when the circuit is complete. Then you just wiggle the wiring and watch to see if the light goes out. Twist the ends of the wires together and maybe use a little tape so you don't have to hold them. Its not elegant but it might be cheaper than going out and buying a meter if you don't already have one. You can test it by touching the two wires together and the light should come on.