How Long Can You Drive with Rod Knock? – Key Points Explained

Updated: | Author: Steve Freling | Affiliate links may be present.

Ever wondered why does it sound like a tiny hammer is tapping in your engine? This annoying sound is probably rod knock. While any unexpected sound from a vehicle is cause for concern, rod knock should not be ignored!

Rod knock occurs when the connecting rods in the engine make contact with the metal in the crankcase. The result is a knocking sound that slows down when you decelerate and speeds up when you accelerate. Rod knock will destroy an engine. Sometimes this happens quickly, sometimes it may take up to a few months. It is important to take a car with a rod knock to the mechanic as soon as possible.

How Long Can You Drive with Rod Knock?

There is no definable answer to this question. Some vehicles shut down immediately once they get rod knock. Other vehicles may rattle along for months, or even years with rod knock. It is best to take the car in as soon as possible when rod knock is first detected.

A vehicle with rod knock is a vehicle with occurring engine damage. The metal-on-metal contact under the hood will eventually destroy the engine.

What Is Rod Knock?

There are connecting rods in the engine that connect the crankshaft to the piston head. In between the rods and crankshaft is a soft bearing with a tiny gap to allow oil to flow through the engine. The oil lubricates the parts and keeps them moving smoothly.

When the gap between the parts grows, the rods are often not properly cushioned which results in knocking sounds.

Causes of Rod Knock

There are two primary causes for rod knock. It is usually a sign of a spun bearing or an issue with the oil in the engine.

Spun Bearing

The bearings between the rods and the crankshaft and piston head can spin out of position. This might happen after hard driving or due to a manufacturing defect.

Oil Issues

Obviously, oil is a crucial component in your engine! The oil in the engine keeps the rods lubricated and prevents metal-on-metal contact in the engine. Low oil, dirty oil, or a loss of oil pressure may cause rod knock.

Signs of Rod Knock

Rod knock makes a low knocking sound. The sound speeds up when you accelerate and slows down when you decelerate.

Will Rod Knock Damage the Vehicle?

Rod knock will not improve or fix itself. Once it starts, it is only going to get worse! Eventually, rod knock will destroy the engine. Every sound of rod knock is an indicator of further damage. The rod will eventually snap.

What Should I Do If I Have Rod Knock?

It is possible to slow down the damage from rod knock by adding heavyweight gear oil in the crankcase. However, this is a very temporary fix! Your best bet is to take the vehicle to the mechanic as soon as possible to minimize the damage to the engine.

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About Steve Freling

Steve has worked for more than 20 years as an automotive mechanic, and later run his own repair shop for both cars and motorcycles. He's a maintenance freak, and generally pretty good at troubleshooting!

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