Sl 350 Balance Shaft - what is this thing

[-raj-]

on the dip stick are you filling the oil to the max?

 

[Geoffps]

Originally I put in 8 litres because that's what the manual said. I checked the dipstick and it was slightly above max but I left it and got the warning message so I sucked some out and reduced it to at max and got the message again so I reduced it to min then got the message so I now have it midway between min and max. In the meantime, I have changed the sensor but still get the message although today was the first time that the message went off when I was driving slowly.
The new sensor has only been in since the dipstick has read midway between min and max, perhaps I should put a bit more oil back in?

 

[Blobcat]

Originally I put in 8 litres because that's what the manual said. I checked the dipstick and it was slightly above max but I left it and got the warning message so I sucked some out and reduced it to at max and got the message again so I reduced it to min then got the message so I now have it midway between min and max. In the meantime, I have changed the sensor but still get the message although today was the first time that the message went off when I was driving slowly.
The new sensor has only been in since the dipstick has read midway between min and max, perhaps I should put a bit more oil back in?

You should use the manual as a guide as the 8 ltrs will be for an engine with no oil in at all. No matter how well you pump out or drain the oil there is always some left in the engine.
I start with 6 ltrs then leave it to run down to the sump, then check and add small amounts from there until dipstick showing the correct level.

I’d then take it for a drive to get warm then leave it for awhile to drain down and measure again.

 

[LostKiwi]

Check all your breather hoses are clear and that the breathers are operating correctly.
There's a potential clue in that the light went off when you slowed down.
A blocked crankcase breather can prevent oil return from the top of the engine thus making the sensor detect low oil because it's held at the top of the engine by crankcase pressure.

 

[Geoffps]

Thanks, I did check the crankcase breather but I haven't checked the hoses, I'll look as soon as I can. (hospital for an operation tomorrow)
I've just been for another drive at a steady 60mph. After about 15 miles the warning came on, about 4 miles later (still doing 60) it went off, 8 miles later it came on, 4 miles later it went off (still 60) then I came home with it still off. I think the 'going off when I slowed down' that I mentioned before was coincidental

 

[Geoffps]

With a red face, I'll own up to what happened here. It might be useful to someone else although it's unlikely that anyone will be as daft as me.
I changed the oil filter, then re-screwed the filter unit back in until the 'O' ring started to bite and left it there. Thereafter I've had the 'check oil level' warning come on when the engine is hot until... I tightened the filter down all the way to the proper torque setting. Problem solved.