What is this sensor? It's leaking oil I think

Hi, so this part is leaking oil directly onto the gearbox. I’m pretty sure the engine is a 4g93 SOHC. It’s from a 2002 Lancer wagon. It’s a manual, don’t know if that helps. It seems simple enough to unscrew, and I thought it was the oil pressure sensor, but that’s at the back of the block (I think), and this is under the dizzy. Everywhere online mentions changing the oil pressure sensor by the filter, so hence me thing it’s something else.

Anyone have any idea what it could be ? Thanks !




Oil pressure sensor.

Is this the 4-banger, or 6? If the 2002 Lancer 4, and the wire is blue/yellow, right-front of engine, that’s probably the oil pressure switch. If the wire is yellow/blue, rear of engine, probably the coolant temperature sensor for the gauge.

4 pistons in this one. ok cool, I did think it was the oil pressure switch too, but I unplugged it and no oil light came on…

I’ll get a new switch, slap it in and see what happens. Worst case scenario, I fix the leak.

Thanks !

Try this; ignition switch on but do not start the engine. Oil pressure light should be on. Unplug the oil pressure switch, light should be off.

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Don’t try to fix the leak by overtightening it. Those usually just need to be snug. I’ll sometimes wrap a little teflon tape around the threads if they continue to be problematic. I don’t think I’ve ever had to do that w/an oil leak, but with coolant leaks at screw in sensors, sometimes it does the trick.

Thanks for the helpful tips! I’ve ordered the part so hopefully it comes in a couple days, and we’ll see what happens then. I’ve fixed a few leaks on the lancer, done 230ks right now but she’s a perfect car, good on gas, easy to drive, decent sized wagon, she ticks all the boxes! Well, apart from power…

Less power = less compression = fewer leaks :slight_smile: