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Discussion Starter #1
There have been a lot of topics about oil lights on google, but nobody seems to have the same problem I do.
Oil light will randomly come on and beep once, and it will go away when I shut the engine off and start it back up.
It will not come on for another day or two, after driving 50-100 miles.

It never appears when I'm driving on highway or above 30 mph, mostly while I'm slowly moving through a parking lot (5-10 mph).
Mostly 1k-2k RPM while in lower gear.
Oil was changed a week ago with Mobil 1 0W-40, K&N 3001 filter.
1999 Passat GLX 2.8L, 155k miles.

Thank you everyone for your help!
 

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Try putting a Mann or VW oil filter on the car, just for confirmation that the bypass pressure setting on the K&N oil filter is not causing a problem.
 

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Discussion Starter #3
Try putting a Mann or VW oil filter on the car, just for confirmation that the bypass pressure setting on the K&N oil filter is not causing a problem.
I will with my next oil change. Thank you!
I've been running K&N for the past 25k miles with no problem though, weird if it is an issue
 

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You could check for a bad connection or faulty oil pressure sender switch.
But I suggest you first check the oil pressure after driving for at least 20 minutes.
 

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1. Check oil pressure (as suggested by Tomvw)
2. If pressure OK, check sensor/wiring for issues
3. If checks ok, get rid of K&N and either go with factory VW filter, which are cheap, or Mann
 

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Discussion Starter #8
You could check for a bad connection or faulty oil pressure sender switch.
But I suggest you first check the oil pressure after driving for at least 20 minutes.
I will get the oil pressure gauge today. Thank you for your input!
Will also clean the connection and see if it eliminates the problem.
 

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To help you interpret the oil light indicator...

The light will not come on below a specific RPM, no matter how low your oil pressure is. I think the cutoff is about 1500 RPM.

The sender is a simple on/off switch that's triggered by pressure. When the oil pressure hits about 20 psi, the switch goes closed. The instrument cluster monitors that circuit. The cluster only knows the state of that switch. It doesn't know anything else about the oil pressure. And as mentioned above, the cluster won't tell you the switch is open whenever the RPM's are below about 1500 rpm.

You could have 10 psi at idle and the light won't turn on due to the above rule. Then as you accelerate and the RPM goes up, so does the oil pressure. As long as the pressure gets up to the minimum the sender switch wants to see by the time you hit the RPM cutoff, the light won't come on.

After you drive the car a while and the oil hits full operating temp, it becomes thinner. When it's thinner, the pressure goes down.

The only way to know what your actual oil pressure is, is to install an oil pressure gauge. Running the engine till it hits full temp on the coolant temp gauge is not enough to get the oil up to full temp. You've got to drive the car a while before the oil gets fully hot (and fully thin).
 
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