Weird oil pressure light turns on

[Otisg]

Hello Guys,

I'm new here and I have a weird problem with my 2011 gti 300. Sometimes(there is not any permanence in the phenomenon) when I start the bike and after few hundred meters the red oil pressure light(not the service) shows up, but after I am increasing the RPM it's disappear and everything is working again like it should until this is repeated in similar way. Directly after the start it disappears normally. The oil switch has benn replaced, oil and filter also changed 200 km ago and the level is fine, but the phenomenon still exist. I have two tips:

1. Oil pump malfunction(but I never experienced Oil pump malfunction in any of my vehicles), and if it has any problems the light should lights continously.

2. Oil pump chain: if it stretched could it cause something like this?

Am I on the right track? Did someone experienced such thing like this?

Thank you and regards!

[Stig / Major Tom]

Hello, welcome to the forum!

How many miles on your 9 year old scooter?

Stig

[Otisg]

Hi Stig,

Currently 22000 KM.

Thank you!

[JJJoseph]

Some Kymcos (every one I have owned) turn on the oil pressure light when it needs an oil change.  I estimate it goes on every ~2000km.  There's a slot below the speedo to turn it off and it stays off for the next 2000km.

[Otisg]

That is right, but in this case I am speaking about the oil pressure light on the left side not the oil service light on the right side.

[CROSSBOLT]

Have you done a valve clearance check yet? When you are in there, notice carefully how oily things are. Everything needs to be covered with oil.
This is a really low pressure system. The only thing the pump does is move oil to the cam area. With all the ball and roller bearings the lower end does the splashing and the upper end gets pumped. The pressure switch must be an oem part since the pressure is so low.

[Otisg]

Yes it was, some weeks ago we have changed the valve cover gasket, and the mechanic said everything was fine there. And also yes, the spare oil switch is oem(I did not know there is aftermarket).

[CROSSBOLT]

Depending how far you wish to pursue this you may want to consider the following:

1. Remove pressure sensor and start engine BRIEFLY to see oil squirt out the hole. Clean up mess...
2. Connect low pressure to sensor hole to see what pressure you get (0 - 5 psi or 0 -10 psi max).
3. Rig up or have someone test the sensor to find switch on pressure.

I have a feeling all is right with your engine but either your oil is too light a weight, the pump is bypassing or the sensor is wrong.

[Otisg]

Hi Karl,

Thank you for the advises. The sensor is brend new(this was the first thing what I changed), the mechanic does not find any dirt or problem there. I have changed the Motul scooter expert 10w40 to Motul 5100 10w50 oil also approx 200km ago.

[JJJoseph]

That is right, but in this case I am speaking about the oil pressure light on the left side not the oil service light on the right side.

I was talking about the oil PRESSURE light.  It has 2 functions. I don't have an "oil service light".

[Manzat]

Hi everybody
My Kymco GT300i , year 2011 with  11000 miles.
 Since i bought this Kymco in may 2021 ( 8000 miles) ,  the oil pressure light has been coming on unexpectedly. Generally, after a cold start and after driving for a few hundred meters (but sometimes with the engine hot and the engine idling). I stop the engine. I need to start and stop the engine 3 or 4 times before the oil pressure light goes out. After that, no problem for hundreds of miles (or less). As if the oil pressure relief valve remained stuck for a moment.
Work done: need to dismantle the entire right side of the GT300i. I bought a new relief valve (ref: 15200-KED9-900); disassembly of the right engine crankcase; assembly of the new valve after checking that it slides correctly; right crankcase reassembly. Road tests and driving (1000 miles) since. No problem. No unexpected lighting of the oil pressure warning light.
Warning: First of all, if the oil pressure warning light comes on, you must stop the engine immediately and carry out the following checks: Check the oil level, the quality of the oil, the oil filter, the noise of the engine (abnormal or not). Ask for advice
Can be useful .