Oil Pump Making Noise? Diagnose the Issue Fast

By Content Sinocmp · June 27, 2025

Hearing strange noises from your oil pump? Don’t ignore them. A noisy oil pump is often the first red flag that something serious is brewing under the hood. Left unchecked, what starts as an odd whine or grind can lead to catastrophic engine failure or expensive repair downtime. As a supplier of heavy-equipment aftermarket parts, SINOCMP knows how critical quick diagnosis and repair are for your fleet. Let’s dive into why your oil pump is screaming for help – and how to silence it for good.

Why Do Oil Pumps Make Noise? Common Culprits

Understanding the root causes helps you fix the problem faster. Here are the most common culprits:

1. Low Oil Level: The Silent (Then Loud) Killer

One of the most frequent causes of pump noise is simply not having enough oil. When oil runs low, the pump sucks in air, leading to a whining or growling sound. This aeration decreases lubrication efficiency and causes internal damage over time.

Quick fix: Check the oil dipstick. Top off with the correct grade of oil if levels are low.

2. Worn Oil Pump Gears

Oil pump gears (or rotors) and bearings wear over time, especially in high-mileage vehicles or under-maintained machines.. As gaps form, you’ll hear a consistent grinding noise – like gravel in a blender. This is a red alert for component failure.

Insight: If the noise persists after oil and filter replacement, inspect or replace the pump itself.

3. Clogged Strainer/Screen: The Blocked Path

A dirty strainer restricts oil flow, forcing the pump to work harder. Listen for a ticking or chattering noise – it’s the pump struggling against debris. Common in dusty job sites or neglected maintenance schedules.

Action step: Replace the oil filter with an OEM-approved unit every 3,000 to 5,000 miles or per manufacturer specs.

4. Incorrect Oil Viscosity

Using oil that's too thick or too thin for your system can cause cavitation or excessive internal friction, resulting in strange noises. This is especially true in colder climates.

Solution: Match your oil type to the equipment’s operational requirements. When in doubt, consult your owner's manual.

5. Loose or Misaligned Drive Shaft

In many machines, the oil pump is driven mechanically. If the drive shaft is loose or worn, it can lead to clicking or metallic clanking sounds.

Pro tip: During regular maintenance, check for shaft wobble or misalignment and tighten all connections.

Step-by-Step Diagnosis: Be Your Own Mechanic

Step 1: Visual & Fluid Check

Inspect oil level/density (old, contaminated oil amplifies noise).
Look for leaks (cracked lines, loose fittings, let air in, and noise out).

Step 2: Isolate the Noise

Run the engine at idle vs. high RPM. Does the noise change?
Use a mechanic’s stethoscope (or a long screwdriver) to pinpoint if the sound comes from the pump itself.

Step 3: Pressure Test (For Hydraulic/Engine Pumps)

A drop in oil pressure paired with noise confirms pump failure. Use a SINOCMP Pressure Test Kit for accuracy – our parts are built to OEM standards.

Fixes That Last: From Quick Wins to Full Replacements

Quick Fixes (For Minor Issues)

Top Off/Change Oil: Use high-quality, viscosity-correct fluid (SINOCMP recommends OEM-grade oils for our pump replacements).
Clean/Replace Strainer

Major Repairs (When Components Fail)

Gear/Bearing Replacement: If you’re handy, swap worn parts with precision-engineered oil pump components.
Full Pump Swap: For older machines, a new SINOCMP oil pump (backed by a 6-month warranty) is cheaper than engine rebuilds.

Prevent Noise (and Failure) Long-Term

Maintenance Schedule Must-Dos

Replace oil every 250 - 500 hours (or as per OEM specs).
Use magnetic drain plugs to catch metal shavings (early wear warning!).

Upgrade to Reliable Parts

SINOCMP’s oil pumps are tested for durability in extreme conditions, from - 20°C job sites to 100% duty cycles. We’re not just selling parts; we’re preventing headaches.

Final Thoughts: Don’t Ignore the Soundtrack of Failure

A noisy oil pump is never just background noise—it’s a warning. Catching the issue early can save thousands in repairs and protect your equipment’s lifespan. With this quick-action guide, you can identify and fix the problem before it snowballs. Stay alert, stay proactive, and let the sound of your machinery be one of power, not distress.