Oil change now oil pressure light permanently on

[chriscburgess]

So i did a quick oil change today - something i have done loads of times before. Now the oil pressure light is permanently on.

Have checked oil level and that is fine.
Have removed wire from switch - light goes out (obviously)
Have reconnected wire - light stays on.

Any clues? is there another wire somewhere that can also affect it?

Thanks
Chris

[itchyfeet]

did you use the same grade oil?
What brand of oil filter?
I would not run it without changing oil filter and or switch in case filter or switch is faulty

[chriscburgess]

Yup - Same oil 15-40 mineral.

didn't change filter as this was an intermediate oil change i.e. change oil twice a year and filter once a year. I only do about 3000 miles per annum

[itchyfeet]

Ok so change switch but personally I would get the pressure checked or buy a guage to do it yourself for the same money.

[chriscburgess]

Ok I will change the switch but did do that a few years ago. If that does not work I will get a pressure tester. Will this one do? http://www.ebay.co.uk/itm/BERGEN-TOOLS- ... 25a2aeec7c" onclick="window.open(this.href);return false;

I also read on the wiki that with ignition on but engine not running oil light should flash but mine is on permanently. Is that correct?

Thanks for your help.

[itchyfeet]

Yes oil light should flash afaik
that ebay link is not clear, you want 0-10bar range, if the range is too much you won't get an accurate reading when pressure is around 1-2 bar

[marlinowner]

Oil pressure light should be on constantly - not flashing - until engine started (just checked mine). Make sure kit has got adaptor for M10x1 thread.

[itchyfeet]

My late petrol van flashes oil light on ignition only
sounds like the later vans flash the earlier vans don't

[marlinowner]

The buzzer of doom circuit must be what makes it flash, its disconnected on my van.

[itchyfeet]

The buzzer of doom circuit must be what makes it flash, its disconnected on my van.

Late van 'disconnect ' is only really possible on the green rev counter wire.
ignition on only would not have a rev counter pulse on that wire so dash would be ignorant to engine speed anyway.
Bod high pressure switch is normally open with engine not running ( closed with oil pressure) so perhaps grounding it changes light state?
not really relevant to op anyway as he has the early single switch dash.

[marlinowner]

Hmm mine is a 1993 SA van with the high pressure switch replaced with an oil temp sender, and the dash PCB is a replacement which has no buzzer circuit, so maybe what my oil light does with ignition on might not be representative...

[chriscburgess]

do you think it would be worth taking out and cleaning the oil pressure switch in thinners/paraffin?

[itchyfeet]

You can try but they are cheap enough to just replace.

[chriscburgess]

UPDATE!

So I changed the pressure switch. Started the engine from cold the oil light went out. Ran it for 10 mins on driveway - still out.

Went out for a run and after about 5 miles light started flickering at tickover and then at traffic lights came on permanently. If i keep the revs up it goes out.

So it appears that once the engine/oil is warm the light will come on at low revs.

This is the first time I ever changed the oil without changing the filter and the first time this has ever happened.(read on here somewhere that if it is an intermediate oil change there is no need to change the filter)

Could the filter cause the problem?

Is it possible to change filter without draining the oil or will it all just gush out?

thanks again for any advice.

[itchyfeet]

Yes change filter but I think you need to brace yourself for the possability it's got low oil pressure
next step is to get it tested or buy a guage and test it for less money

this is the one I have ( I also have a dash one now also)

http://www.ebay.co.uk/itm/NEW-Engine-Oi ... 3f2ece50aa" onclick="window.open(this.href);return false;