Idiot Light.....? Update 15 Apr 2024

[USAF Sarge]

2006 Ford Expedition Ltd....

About a week ago when my wife was pulling into the neighborhood the Low Oil Pressure Light came on and the Oil Pressure Gauge bottomed out a few times and then everything went normal.

Let the Beast sit for a while, checked the oil level and all was good. Checked again in the AM before a doctor's appointment and level was just under the full mark.

No problems for a few days and it happened again today. Same symptoms as last time, a few dings, Low Oil Pressure Light came on, the Oil Pressure Guage jumped up and down again. Checked the level after the Beast sat awhile and still just under the full mark.

So is this a sensor going out or something else going on, like a bad pump or sending unit?

What should I be looking at to rectify this?

 

[whtbronco]

The oil pump being mechanical it's unlikely it would fluctuate pressure from normal to zero. So I'd be looking at a sensor, wire or a connector. I would start with a scan for any codes that will likely provide some guidance.

 

[USAF Sarge]

Sorry for the late reply, I'll take a look see and do some troubleshooting and see what I can find.

Thank you for pointing me in a direction to solve this.

 

[USAF Sarge]

The oil pump being mechanical it's unlikely it would fluctuate pressure from normal to zero. So I'd be looking at a sensor, wire or a connector. I would start with a scan for any codes that will likely provide some guidance.

So the Beast was in the shop last week for some work. For tie rods, control arms, complete brake job (front and rear) and while there an oil change. No issue for a few days then it started doing it again today.

While in the shop they pulled the codes. The only code it's throwing is the ongoing P0456 "Evaporative emission control system leak (small)," we've been having for a while. Hence why the check engine light is on. Changed out the gas cap twice and that didn't fix that issue. Going to look at the vacuum lines next, for that issue.

Back to the new and main issue at hand.

The "Oil Pressure Low" light only comes on when coming to a stop (Idling?). With the mechanical guage bottoming out, plus the "Check Gage" light coming on. Then everything goes normal.

We know it's not low on oil, and it's not throwing any codes regarding anything but the EVAP leak.

A quick picture my wife took when out running errands this morning showing the dashboard. Kept doing it everytime she stopped. Then after stopping and shutting it off when she stopped for breakfast, it didn't do it again all the way home.

 

[whtbronco]

I'm thinking maybe you need to test the oil pressure sensor. It's pretty easy to do, it's a single wire sensor and the article below describes it fairly well. Access to the sensor might not be so easy though.

How to Test Oil Pressure Sensor with Multimeter (In 3-Steps)

A car's oil pressure sensor is important to test when you are performing repairs to your car. This 3-Step guide shows you how to test it with a multimeter.

toolsweek.com

The oil pressure sender mounts to the backside of the oil filter adapter. I think your 2006 is the same as my 2004 for this. If you decide to replace the sensor/sender it's fairly low cost at $17 plus tax/shipping from Rock Auto or $21 plus tax from Amazon, MOTORCRAFT SW8368.