When warm, the oil pressure light on my ST4 has started to flicker at tickover. I have checked the oil level and that's ok also, I am also using the right grade oil (10w40 Castrol GPS). Having looked in MCN this week, someone had the same problem witha Suzuki and they suggested it could be the switch or oil pump. Could this be the same on my ST4? Is the switch easy to get at and the cheapest first option to try (somewhere else it suggests VW Polo switch fits!). Any suggestions? Thanks, Greg
The oil pressure switch is well known to be a little flakey and will give the symptoms you describe. You'll usually see it flicker at tick over then go out when the revs increase but after a bit it will start to come on all the time even though you know that there is oil in there.
It's less likely to be the oil pump, but you never know...
I had the oil light come on solidly on a rideout once - even though I knew it had oil. I had no choice but to ride it, so I topped the oil up then rode it gently and ready to stop at the first sign of stress from the engine. After I had ridden a few miles I figured that if oil light was on solid and the engine hadn't blown by now it wasn't going to so I rode normally for a couple of weeks without a problem until the switch was replaced
Your plan to change the oil switch first sounds like a good one
I've experienced the same as Jools. Dodgy oil switch was the culprit. Remember though that the oil switch indicates lack of oil pressure not low oil level, which would need to be very low indeed for the switch to light up. By which time your engine would be trashed.
And yes, Volkswagen Polo switch. M10x1.00mm thread and contacts normally closed.
Fitted new switch very carefully last night (not too tight!) and went out for a ride and got the bike nicely warmed up. The light not now flickering at tickover so fingers crossed. I will take the bike out for a long ride at weekend and see if is still ok. Thanks for all the comments.