Q: Oil pressure sensor....need changed or just dirty

You may still want to have the system checked in person for a possible bad sensor or connection to the sensor. After washing, you may have washed away some corrosion on the connector to the sensor. If you have a professional inspect the system, have them check if the connector and sensor are having any type of connection or corrosion problem.

Also, Chevrolet uses the oil pressure on some models to let the computer know if you have enough oil pressure to keep the engine operating normally. Your engine may have a blockage in the oil pressure sender passage that goes to the lifters and may need to be cleaned out. This instance would cause the sensor to not get pressure from the engine due to blocked passages. The manufacturer has a technical bulletin for this issue and the processes to clean out the passages and oil sender if this is indeed the problem. If you would like to have this checked, a mechanic, such as one from YourMechanic, can come to your home or office to inspect your oil system and determine if an oil pressure sensor replacement is needed.