benjai

It comes on, but only feintly and then goes off again after a couple of minutes??????

In the old days the light was either on or off and indicated low pressure in the oil circuit, but now it's more complex. I know (I think) that you can extract oil pressure data from the car which means that the sender is not just a pressure switch, but a pressure sensor, and this leads me to presume that the light is a logic output from a computer somewhere (unless there is also a pressure switch). Either way, I expect the warning light to only have two states - on or off so I'm confused.

Perhaps more importantly, should I worry about it or just stick something opaque over the light and hope it goes away?????

Anyone got any ideas????

TonyBurns

iTrader: (3)

I take it you have checked the oil level?

Tony

benjai

Do you think that could be it then ????

Yes, the oil was a little low, actually below the min level mark, but half a litre got it back up to just under max.

I discounted this as I assumed that low pressure it indicated if the oil pump is pumping air, and I assume that if the oil pickup is positioned so that it does this if you drop 300ml below optimum it's in the wrong place??!?!?! I would also still expect a logic 1 indicatoin - i.e. the light ON.

I was more worried that it could be an earth leak somewhere as a result of water in the electrics (it has been rather moist recently) !

ALi-B

iTrader: (1)

Simple way: Get someone to check you oil pressure with a gauge.

The light is operated by a switch at 3ish psi. The engine should be running much more than that, so if there is a oil pressure problem, it will be pretty obvious from the gauge reading.

You say the light only comes on faintly which may point to a bare wire shorting to the chassis somewhere or a dodgy sender...but best to get it checked out to be sure.

stevebt

iTrader: (8)

you want to hope that it is only wiring as once that light comes on, it isnt red for nothing !!! it means if it comes on for a proper reason your engine wont last much longer !!!!

on a different vehicle i ruined my engine by driving 15 miles when the oil light kept coming on,after starting the engine it would dissapear after about 2 miles but each drive was killing the engine more, was an expensive lesson

Turbotits

iTrader: (2)

Has this just started since weve had all this rain or have you been through any major puddles?Water on the switch can sometimes take the wiring straight to earth bringing on a very faint oil light.Normally intermitant and can light up faint at anytime ie.idle,Flatout or any where in between. Try removing the wire from the switch and cleaning/drying the switch and the wiring plug then re-connect and see what happens.

Mica Blue

The light comes on at very low pressure, so if the light is on, you are already doing serious damage to your engine.

Ninnybobs

Benjai,

Just out of curiosity, what MY are you driving?

I have had the same problem with an MY01 (bugeye). My problem was not related to either low oil levels or low pressure as both were fine.

Oil light would illuminate VERY dimmly (almost not noticable) and go off after a couple of minutes.

Thinking about it, the weather was usually damp when it happened.

Martin

pimmo2000

iTrader: (6)

I've always been told if the oil light comes on the cars already too far gone to be repaired Best of luck

jaytc2003

iTrader: (1)

does this happen when driving in a straight line or when taking bends? if it is a straight line and under normal driving conditions then I would say there is a short there somewhere. If it only happens when going round bends then I would say it is oil surge and low oil level.
Like you say there should only be 2 states, on or off so if it is lighting faintly then I would say it is more than likely to be a short.

New_scooby_04

iTrader: (4)

If I saw a oil light on a car it'd be over to the kerb switched off and onto the back of a trailer en route to a garage before you could say "re-build" Best to assume worst case scenario and be pleasantly surprised to be wrong in this situation methinks!

Best of luck!

NS04

justanotherperson

The red light is just an idication of wether you should be carrying your cheque book with you,red light on=cheque book time

benjai

Martin,

It's a MY03 and it sounds like exactly the same thing. Just for everyone else who has tried to help (thanks).
1. It only happened once, first thing in the morning on Monday, and I had washed the engine bay the night before
2. The light was never ON, it just wasn't fully OFF
3. It was not road speed, engine speed or g related

I was pretty sure it wasn't a genuine indication of low oil pressure, which is why I wanted to know if there was a separate switch circuit on the sender which could dimly light the bulb if there was a current leak across it. I'm now convinced that this was the case, especially as it has only happened once and several hundred miles later nothing has gone pop.

If the light had actually come ON I would have stopped driving immediately. The last time I didn't, I ended up with a snapped crankshaft but that's another long and very painful story (and you will be glad to hear does not inolve a scoob)

Turbotits

iTrader: (2)

That'll be why then,Water on the switch earthing it out as per my previous post.