For 1990-2009 cars

• | With the vehicle on a level surface, allow adequate drain down time (2-3 minutes) and measure for a low oil level.

| Add the recommended grade engine oil and fill the crankcase until the oil level measures full on the oil level indicator.

• | Run the engine and verify low or no oil pressure on the vehicle gauge or light.

| Listen for a noisy valve train or a knocking noise.

• | Inspect for the following:

- | Oil diluted by moisture or unburned fuel mixtures

- | Improper oil viscosity for the expected temperature

- | Incorrect or malfunctioning oil pressure sender

- | Incorrect or malfunctioning oil pressure gauge

- | Plugged oil filter

- | Malfunctioning oil bypass valve

• | Remove the oil pressure sender.

• | Install a oil pressure gauge and measure the engine oil pressure.

• | Compare the readings to specifications. Refer to Engine Mechanical Specifications.

• | If the engine oil pressure is below specifications, inspect the engine for one or more of the following:

- | Oil pump worn or dirty.

- | Refer to Oil Pump Clean And inspect.

- | Oil pump-to-engine block bolts loose.

- | Refer to Oil Pump Installation.

- | Oil pump screen loose, plugged, or damaged

- | Malfunctioning oil pump pressure regulator valve

- | Excessive bearing clearance.

- | Refer to Crankshaft and Bearings Clean and Inspect.

- | Cracked, porous or restricted oil galleries

- | Oil gallery plugs missing or incorrectly installed.

- | Refer to Cylinder Block Plug Installation.

- | Broken valve lifters