oil light on at high speed and very hot outside

[mvladutoiu]

Hi guys,
my bike's been running good lately, so I took her out for a spin yesterday on the local freeway. I had something happen that I never had before. Very hot outside, temperature close to 40 Celsius (about 100 Fahrenheit). I decided to crank her out a little bit after cruising at 130 kmh (70 mph) but when I got to about 180 kmh my oil light came on. As soon as I let off the gas, the light went off. I tried it again and had the same results. The oil level is good, close to the upper limit when engine is cool and I check on the side window of the engine case.
Any ideas is there is a connection between outside temp and speed? Oil is been changed recently to Repsol 4T V-Twin 20W50.

[FJmonkey]

If the oil is topped off then don't worry. It is only a low oil warning light. Ride it dude...

[Pat Conlon]

+1 ^^ Yes, it's very common on FJ's. Don't worry about it. Enjoy that bike.

[balky1]

It has stupid float system to check the oil level instead of oil pressure sensor. So whenever it gets to some point, turns the light on, but if you are sure you have enough oil, don't worry and ride it hard. 

No connection in air temp-riding speed. Oil thickness is good. I use 15 W 50.

[ribbert]

It has stupid float system to check the oil level instead of oil pressure sensor.


No connection in air temp-riding speed.

I read somewhere on this forum that an oil level light lets you know when you're getting low on oil before it becomes dangerously low, an oil pressure light lets you know when you've completely run out of oil, by which stage you've stuffed your engine.

I also read somewhere that oil gets thinner as it gets hotter and the higher the sustained revs, the hotter it gets and because it is air cooled, the hotter the ambient temperature, the less efficient the cooling becomes, even hotter oil.

It has also been said on the forum that the acceleration required to surge the oil away from the pickup is only achieved in the lower gears, not between 130 and 180, unless the oil level is very low.

Dodgy oil level lights have a long history on the forum, from crook senders to wires shorting out. As has been said, if you have checked the oil level, don't worry about it.

Noel

[pdxfj]

Many have found that keeping the oil level above the full mark will keep the light off.  I'm sure a fair number of people here (myself included) use a full 4 quarts of oil when doing changes.  Even though this is more than is recommended in the owners manual, adding the extra oil has no ill effects.

So roughly 3.75/3.80 liters for you?

[ffjlaw]

My FJ does the same thing under the same conditions.  I've been told by experienced FJ owners,(which I'm not), that this is normal.  I was told to check my oil level with the bike off stand, upright, and if was in normal range not to worry.

[Dads_FJ]

Just think of it as a shift-light.  

[mr blackstock]

G'day,

Quite a few months back I had  issues with my oil light coming on, at first occasionally, then constantly.  i thought I had the fault solved when I checked some wiring, then it came back.  I tracked it down to the diode.  Under the fairing, upper left frame.  Little square box with rubber cover, plastic tied to the frame.
I let it hang free, and the problem disappeared, re-attached it to the frame and it came back. 

It may be the cause of your issue as it appears when the engine is revving/vibrating, then disappears when the revs/vibrations die off. 

Perhaps give that a try?

cheers, Gareth

[balky1]

And I check the oil level as a must every time before first start of the day because I was told FJs like to leak gasoline into oil and if I try to start it with this happened I could end up with bent connecting rods and some other damage.

So if you check it like me every time, and you are sure there is enough oil - no worries. But the light is anoying, for sure.

[movenon]

And I check the oil level as a must every time before first start of the day because I was told FJs like to leak gasoline into oil and if I try to start it with this happened I could end up with bent connecting rods and some other damage.

So if you check it like me every time, and you are sure there is enough oil - no worries. But the light is anoying, for sure.

"I was told FJs like to leak gasoline into oil"  Not really.  Not more than any other carbed bikes.  Certainly something to know about and check.   All the FJ's have 2 systems to stop excess fuel flow but inspections and awareness is good.  Just like air pressure and chain inspections.   
George

[Mark Olson]

And I check the oil level as a must every time before first start of the day because I was told FJs like to leak gasoline into oil and if I try to start it with this happened I could end up with bent connecting rods and some other damage.

So if you check it like me every time, and you are sure there is enough oil - no worries. But the light is anoying, for sure.

Well my 86 had a petcock failure at 14k and flooded the crankcase resulting in bent rods...the symptom is a slow cranking no start ...so you hook up jumper cables from a car battery and that,s when the damage happens.

As for the oil level light, I have found if you use an oversized spin on filter it will drain back and give a false oil level after sitting .
So what I found works is to start engine and lt warm up to idle /choke off. Then stop engine and put FJ on center stand. Wait ten minutes and check oil level ...now add as needed.. This gives oil filter a chance to fill up and hold so you get a better reading.

I did get tired of doing this so I change to the k/n filter RPM sells.
I was kicking the oversized with my boot toe when riding.
The k/n filter has an anti drain back feature that actually works.
I fill oil to the top mark and the light will come on only on hard acceleration and tight uphill grades while turning deep.

This was my experience and yours may vary.

[1tinindian]

Many have found that keeping the oil level above the full mark will keep the light off.  I'm sure a fair number of people here (myself included) use a full 4 quarts of oil when doing changes.  Even though this is more than is recommended in the owners manual, adding the extra oil has no ill effects.

So roughly 3.75/3.80 liters for you?

This is exactly how I have eliminated the dreaded oil level light!
4 full quarts of oil and a spin on filter = No oil level light in ANY condition.

[Burns]

it's good to know that 4 qts is still below the froth level (where the crank throws are below the  oil level and turn the oil to foam).

[FJmonkey]

it's good to know that 4 qts is still below the froth level (where the crank throws are below the  oil level and turn the oil to foam).

If you over fill with oil, your crank case breather will leak out the extra oil. It may take a little while but it will self adjust. A little messy as well...