Oil warning light flicker

[smurfbus]

I have a bit of a strange one. The last couple of times of I have driven my van in heavy van (yesterday being the most recent) I'm getting an occasional oil warning light flicking on. Prior to setting off yesterday I did the usual oil and coolant check and all was fine. There's not evidence of oil leak on the drive etc, and the light doesn't seem to come on in the dry. Any thoughts???

[ghost123uk]

I suppose it could be water getting onto the electrics, though in my (considerable) experience this should not cause your symptoms. Water on electrics only really effects delicate "electronics" rather than the simple On/Off functions of the oil pressure switches. Does it do it when the engine is still cool, or only when it gets up to normal temperature ?

I really popped in here to remind you ( ) that the oil light measure the pressure of the oil, not the quantity, so any oil leaks and the level of the oil will have no effect on the light (unless you are very nearly empty of oil ).

[itchyfeet]

Check the wire anyway, if the insulation has come off and the wire is almost touching the metalwork then water lashing on it my be just enough to make it connect, it's a long shot but worth checking.

[ghost123uk]

Of course if it's an 85 (as per sig) it may well have the later 2 oil pressure sensor system, one under the water pump pulley and one under the nearside push-rod stone guard. (link to info on this in our "Wiki" HERE). If it is a short occurring, perhaps made worse by water, it will be the low pressure switch that measures the pressure at lower rpm. The lower pressure switch is the one by the push-rod tubes. If "messing" in there you have to remove one or two exhaust manifold nuts to get access, take care with them, shearing a stud off there is NOT good news. Heat, lots of, and PlusGas (not WD40) are your friends, (though I still doubt it is water related as in water on the wiring )

[itchyfeet]

When you turn the ignition on but don't start do you get the oil pressure light come on?
It should do this is the test the switch is working.

[smurfbus]

Hi, thanks very much for all of your replies. Firstly, thanks for your advice re oil pressure ghost123uk, noted. I'm pretty new to all this, and my total mechanical experience comes from fiddling with an old fiesta 15 years ago.

What you said about the oil pressure light being an on/off switch is interesting though, because on Saturday the light initially came on while driving at 50mph, and then flickered for a few seconds. I quickly turned off the dual carriageway, and while stopped at some lights, the oil light faded in brightness, so dim but still visible. When I pulled away, it flickered brighter again for 30 secs and then turned off for the remainder of the 5 mins it took me to get home.

On both occasions, it's happened the engine has been nice and warm and rain has been torrential with standing water unavoidable.

Itchyfeet, the old light comes on loud and clear when I turn the ignition on, and yes it's an 85dg, and registered late that year (December).

Hoping to get a bit of time with the van this weekend so will check the wiki and go from there. Cue another stupid question : how do I tell which of the oil pressure sensors I have?

Thanks again for your help!

[itchyfeet]

They are not sensors they are switches
one between push rod tubes should have a blue colour on the body and is the low pressure normally closed when engine not running, or no oil pressure
one under the waterpump is normally grey on the body, it is the higher pressure one and is normally open when engine not running or no oil pressure
blue switch is the oil light switch, it needs to be closed to bring the light on. (Hence light on with ignition but not running) it connects to the blue wire in the loom
the latter grey switch is the buzzer switch and connects to the yellow wire in loom, both switches are brown wire across the engine, buzzer will only sound above 2k rpm

if your switches are origional they may not be colour coded.

i say new wire to loom (high temp) then change the sensor if it continues.
also worth checking if you have any sort of water leak around the dash or fusebox

this is worth a read
http://www.brick-yard.co.uk/VehicleSpec ... fo/dop.htm" onclick="window.open(this.href);return false;

switches here

http://www.brickwerks.co.uk/index.php/t ... -blue.html" onclick="window.open(this.href);return false;
http://www.brickwerks.co.uk/index.php/t ... -grey.html" onclick="window.open(this.href);return false;

[ghost123uk]

He's good isn't he ^^^

[itchyfeet]

Not that good, I still managed to call it a sensor

[smurfbus]

Amazing, thanks for that. Doesn't look like I'll get a look this weekend after all, going to the in laws, but will check it out asap