Anyone ever had oil wicking up the inside of a sensor wire? My son's car appears to have oil inside the connector for the engine RPM sensor on the firewall under the radiator surge tank in his 96 2.8L Quattro. Theres no oil on or near the firewall, and no oil in any of the other connectors in the vicinity. Seems like the only way it could get there is from inside the wire itself.

 

Not uncommon. Maybe not so much those sensors, but it happens in coolant sensors, trans harnesses a lot on other cars.

 

A number of people have had ECU connectors corrode inside the ECU box due to coolant wicking up the wires.