To repair an oil pump, first determine the specific problem and then fix or replace the defective part. Common issues with oil pumps include low oil pressure, increased engine operating temperatures and unusual pump noises during operation.
If an oil pump pressure gauge is reading low, first turn off the engine and wait for a few minutes before checking the oil level on the dipstick. If the oil is below the required level, add more until it reaches the recommended limit and then restart the engine. If the warning light is still on, the pressure gauge or the oil pressure sending unit might be defective and may need replacement.
If the engine operating temperatures are too high, the oil pump may be worn out. If an oil pump is worn out, it leaks pressure internally and may not deliver the required oil flow to the engine. Check whether the gears inside the pump are defective and replace them if necessary. Inspect the pump housing or end plate to be sure they are functioning efficiently. Replace any of these components if damaged.
If an oil pump is making a loud whirring sound during operation, the internal gear mechanism might be worn out. Replace a worn out oil pump gear mechanism to solve the problem.
If none of these repair methods remedy the problem, contact an experienced oil pump technician for assistance.