Oil light at startup

[Cletonius]

How long does your oil light stay on after you start the car?

Seems like it used to be maybe 1-2 seconds but I feel like it's staying on longer now. Sometimes maybe 4-6 seconds.

Doesn't matter if fresh oil or not, using regular rotella and Mobil 1 filter. Odo is broken so I change every 3 months as I don't drive a lot. The level is always ok, I check it a few times a week and haven't had to ever add more than a half quart per oil change.

Am I on the way to brokenland?

[dnguyen1963]

Which light...cluster or overhead check light?

[digger]

less than a second (basically stright away) on the old 7psi sensor, now about 1 second with a 12psi aftermarket VDO

[Cletonius]

Which light...cluster or overhead check light?

Cluster light.

[Cletonius]

less than a second (basically stright away) on the old 7psi sensor, now about 1 second with a 12psi aftermarket VDO

My car is a 01/90 build if that makes a difference.

So since mine is staying on is that more likely indicative of a failing sensor, something leaking, or a failing oil pump?

When I got the car it was running rich, it had intake leaks, bad plugs, really old cap/rotor/wires, and a shitty spliced O2 that was not working. When I touched them, the wires basically crumbled out of the butt connector the PO used. There was a lot of fuel in the oil.

[mpowerful]

Aot of fuel in the oil = not good. Could of caused permanent damage to bearings from being to thin. Hence lower pressures especially cold using split weight oil when its at its thinnest. May be time for straight 50weight. Haha

[digger]

My car is a 01/90 build if that makes a difference.

So since mine is staying on is that more likely indicative of a failing sensor, something leaking, or a failing oil pump?

When I got the car it was running rich, it had intake leaks, bad plugs, really old cap/rotor/wires, and a shitty spliced O2 that was not working. When I touched them, the wires basically crumbled out of the butt connector the PO used. There was a lot of fuel in the oil.

i bought a cheap sensor which failed in next to no time. It used to randomly flicker the oil warning light when driving and oil leaked from the plastic part. swapped it out for a good one and light never came on again. i dont know if it is common when they fail to come on earlier than supposed to or whether random things are a sign of failure

i would replace the sensor even the better brand are still cheap.

[dnguyen1963]

Either a cheap sensor, oil is diluted with fuel, or your oil pump is starting to go.

[studawg]

Regular 15w-40 oil is too thick at startup, switch to lower grade oil, with a lower first number, preferably synthetic, and I bet your oil light goes out a lot sooner.

[Cletonius]

or your oil pump is starting to go.

Does it make noise when this happens?

[Cletonius]

Regular 15w-40 oil is too thick at startup, switch to lower grade oil, with a lower first number, preferably synthetic, and I bet your oil light goes out a lot sooner.

I'll give 10-40 a try next change and see what happens

[ForcedFirebird]

Regular 15w-40 oil is too thick at startup, switch to lower grade oil, with a lower first number, preferably synthetic, and I bet your oil light goes out a lot sooner.

What? We run nothing but 15-50 M1 in the m20's at the shop and on track, never have an issue (it also has nice amounts of Zinc). thicker oil would be LESS likely to turn the light on at startup, the thicker the oil, the higher the pressure should be.

Either a cheap sensor, oil is diluted with fuel, or your oil pump is starting to go.

It might be the sensor. They tend to leak internally, through the spade connectors themselves and fill up the wire sheath, because oil is bypassing, it can read low.

I'll give 10-40 a try next change and see what happens

Wouldn't bother. Use a real oil gauge and test the pressure before doing anything. It's a simple, easy and very quick test.

You should be concerned if the light was to be on at idle.

The lights are easily fooled. Had a Spec e30 come in for an engine change because the the light was coming on, so we tested the old engine before replacing it with a rebuilt. The idle pressure started at 55 and dropped to 40 or so after warm up. There was nothing wrong with the first engine, they kept it as a back up.

[Cletonius]

Where would I connect a real pressure gauge?

Actually, where's the sensor for the light ? I'll check it out this weekend.

Thanks for all the replies

[ForcedFirebird]

The sensor is on the passenger side of the block, threads pointed up (connector down) just forward of the motor mount arm. Has a two prong connector like the coolant temp. An oil pressure test kit will have the correct threads to adapt to the gauge in it.

[studawg]

What? We run nothing but 15-50 M1 in the m20's at the shop and on track, never have an issue (it also has nice amounts of Zinc). thicker oil would be LESS likely to turn the light on at startup, the thicker the oil, the higher the pressure should be.


You should be concerned if the light was to be on at idle.

Yeah but that M1 15w50 is synthetic and going to flow much better when cold compared to conventional; the thicker oil would raise pressure but be more resistant to flow;

E30 owners manual states that the oil pressure light "may come on when a hot engine is idling, but must go out when engine speed picks up"