Oil pressure sensor - question...

[crazyfrog]

Hello GS500 world !  . This site is great.

I have a problem with my GS500  - 1991 - GM51B - with 55.000 Km . The oil pressure light  flicker on idle speed.

This is very strange because:

1 - everything it is ok - oil light stay off even with 1000rmp or less. This happened  with an old (aprox. 4000 km) oil.
2 – I changed the oil with 15w50 – because here (in Romania - Bucharest) the day temperature it is high (40C)
3 – After 30 Km the oil pressure light  come ON at the idle speed (aprox 1500 rmp)
4 – next day in the morning I start the engine and the oil pressure light come OFF (after start the engine – this is normal). The light continues to stay OFF even with worm engine
5 – after 150Km – the oil pressure light come ON at the idle speed
6 – I change the oil with 10w40 (this type of oil I use before this happened ) – the oil pressure light come ON at the idle speed
7 – Because I suspect the oil pressure sensor , I took a oil pressure sensor from a GS500-1993(that do not have problems with oil pressure light) -> the oil pressure light stay OFF at the idle speed(even 1000rpm). I was happy J .
So the second step was to put my sensor on that GS500-1993 bike. On that bike (with my oil pressure sensor)  the oil pressure continues to stay OFF even at 1000rmp.

Another thing  that I observe:
My oil pressure sensor:  < p .25 >
On the GS500-1993    :  < p .15 >

So, the oil pressure sensors differs!!!!!!  And my oil pressure light stay OFF(at idle) with  oil pressure sensor type < p .15 >!!!!

Is this normal ?

Why the pressure sensor differs form one bike to another ?


10x

[deathlucky]

im not 100% sure about this but dont you use heavier oil if you live in a hot place or you ride like a mad man. i live in australia and i use 20w 50 oil in my bike because i ride like a mad man

when you swapped to 10w 40 did the light come on faster

sorry i couldn't be of more help

[crazyfrog]

the temperature variation  it is from 15C to 35C (on the road , in a big city probably 50C ).
this year I change the oil in March. The 10W40 seems to be OK for spring season.

This problem appears since  last week when I changed the oil.

[Affschnozel]

Oil pressure may vary from bike to bike depending on condition of the combustion chamber also
If the engine is worn the pressure may pass by the piston rings and increase oil pressure
readout or worn engine parts like camshafts can bring the pressure down,so there can be a big
diference. Just be sure it's not below limit and there's enough oil

[Affschnozel]

Also check the wiring to be sure it's not faulty.
On my bike some wires get pinched in headstock and all flicker sometimes
(i'm not bothered to fix it yet... )

[crazyfrog]

but what about type of pressure sensor ??

in the repair manual (Haynes) do not specify the type....

With oil pressure sensor type <p .15> my bike it is fine.

Can anyone  tell me what type of oil pressure sensor  must have a standard GS 500 E  from 1991

[Affschnozel]

As I understand it GS has mechanically controlled oil pressure regulator which is connected
to oil pressure switch,when the pressure drops it activates the switch.
Are you using some after market oil pressure gauge?

[John Bates]

Both years use the same pressure switch.

See microfich
Part No. 28

[crazyfrog]

10x.

any other suggestion ??

[crazyfrog]

News!

The problem seems to fix itself!   

10x

[ducati_nolan]

I think the oil pressure light is unreliable at best and pretty much worthless. I think that 20w50 is a good choice for the hot temps and even in moderate temps if you have high milage. The oil light has nothing to do with the pressure regulator so you can go ahead and throw it away and install an actual gauge that will give you meaningfull info.