Detecting And Repairing A Faulty Hydraulic Lifter!

Hydraulic lifters play a critical role in your engine’s valve train. They use oil pressure to automatically adjust a small internal plunger, removing clearance between components. This helps reduce engine noise and minimises wear, improving long-term reliability.

However, when a hydraulic lifter begins to fail, it can quickly lead to further damage to surrounding components such as the rocker arm, valve tip and push rod. Knowing the symptoms of a bad hydraulic lifter early can help you avoid costly engine repairs.

What Does a Faulty Hydraulic Lifter Sound Like?

One of the most common signs of a bad hydraulic lifter is a distinct tapping noise coming from the engine. Unlike knocking or pinging, lifter noise is typically:

• A fast, repetitive tapping sound
• Often louder during cold starts
• Sometimes worse once the engine is warm

This noise is usually caused by a loss of internal oil pressure, a sticking plunger, or a blocked hydraulic check valve restricting proper oil flow.

Common Causes of Hydraulic Lifter Failure

• Dirty or contaminated engine oil
• Low oil levels or poor oil pressure
• Worn internal lifter components
• Blocked or sticking hydraulic check valves

How to Fix a Bad Hydraulic Lifter

If you suspect a faulty lifter, it’s important to address the issue quickly. Driving with a failing lifter can cause accelerated wear across the entire valve train.

In some cases, replacing a single faulty lifter may solve the issue. However, if one lifter has failed, others may soon follow. For long-term reliability, many mechanics recommend replacing the full set.

While experienced DIY mechanics can replace hydraulic lifters themselves, professional installation is often advised to ensure proper valve train alignment and oil flow performance.

Hydraulic Check Valves & Engine Oil Control

Hydraulic systems rely on correctly functioning check valves to maintain pressure and prevent backflow. A sticking or contaminated valve can affect oil delivery and contribute to lifter noise.

At Flowfit, we supply a wide range of high-quality hydraulic check valves suitable for industrial and specialist hydraulic applications.