Expedition Oil pressure light: False alarm or cause for concern?

I bought my 2000 Expedition in January of this year. One owner car, well maintained by a car guy. When it's cold out and cold starting the car, the oil light tends to come on. Sometimes, revving in neutral will make it go away. It worried me at first, but knowing the history and with the fact that it went away once warm (at the latest), and occasionally didn't happen at all I wrote it off. Nothing sounded off, and the oil level was always correct.

Now we're getting cold weather again, and I'm hoping someone can confirm/deny that it's a false alarm or tell me what I should be checking to verify this. Its still scary to turn the car on and see that light, as it's my only transportation.

Bad oil filter drainback valve? How long is the light staying on?

Its probably not a big deal, given your description, but the Only way to know what's really going on is to install a oil pressure gauge to test. Personally, if the oil light is coming on, I wouldnt drive it anywhere without knowing what's going on, but it sounds like you've been driving it all year.

Should not be crazy expensive to have a shop hook up a gauge if you don't have access to one.

In reply to BrokenYugo:

A minute or two at most. I'll look into that!

In reply to TGMF:

When it happened the first few times, I pulled over, turned the car off immediately, and on restarting it (1st or 2nd try) the light was off again. During the warmer months (April-2 weeks ago) the light never came on. Just when it's under, say, 50.

You could always replace the stock oil pressure sending unit and see what happens. What weight oil you running in this thing?

A minute or two kinda rules out a bad oil filter (that will be 0 pressure rattle for a second or two at startup). I'd throw a new sensor at it (they do go bad) and go from there.

Might be worth doing a cold start with the hood up and stethoscopes on the valve covers and top of block?

In reply to TGMF:

Plus one for the oil pressure gauge. Cold weather test w/ it, if the oil pressure is proven good w/ cold starts and running just replace the sender.

change oil and filter, see if that helps.

I'm thinking a problem with the oil pick up since it occurs with colder temperatures.

What is the condition of the oil ?

iceracer wrote: change oil and filter, see if that helps. I'm thinking a problem with the oil pick up since it occurs with colder temperatures. What is the condition of the oil ?

I've had the oil changed ~6 times since I bought the car and it's still happening. Current oil has about 2k on it but I'm not sure the weight

Your engine would be dead by now if you had a serious oil pressure problem, I'd say you should change the sensor to be sure. If everything doesn't go back to normal, have a shop check the oil pressure with an external gauge.

this is far out but it has happened.

Moisture collects in the pan, oil floats on top.

Pickup screen frosts over.

Comes from not getting the oil hot.

This happened many years ago.

In reply to classicJackets: Not sure of the weight ?

Have you actually checked the level.

Really, you've got essentially three choices. You can ignore it and hope that it's really nothing, you can fire the parts cannon at it or you can start the diagnostic process by hooking an oil pressure gauge up to it.

iceracer wrote: In reply to classicJackets: Not sure of the weight ? Have you actually checked the level.

Yes, many times over. First car I've gotten standard oil changes with.

I'll likely try to find a way to get a pressure gauge on it over my winter break from school.

You can use the port the sender normally lives in to hook up a test gauge, then screw in a fresh sender when you're done. This goes without saying but do be sure to clean the area first, you do not want any amount of dirt getting in there.