Under the hood of a Honda.

Why is my car making a knocking sound?

In Suspension by HomeTowne Auto Repair & Tire

Trouble sometimes comes knocking.

In the case of a Honda Odyssey, it was steering suspension components.

The vehicle was brought in when the driver heard a knocking sound that seemed to be coming from the engine.

After quite a bit of investigation, our technician figured out the cause: The timing belt tensioner had gone bad.

On top of replacing this component, he installed a new timing belt and related parts. Sometimes, these components come together as a set and it’s best to replace them all at once.

Timing belts ensure that the crankshaft and camshaft have the correct timing. You can read more about timing belts and when to replace them in this article we wrote recently.

A tensioner, which keeps the belt tight, is needed in order for the timing belt to function properly.

A timing belt tensioner.
Timing belt tensioner

Causes of a knocking sound

A knocking sound can occur for a variety of reasons.

In addition to timing belt tensioners, it can be the result of other components, including sway bar end links, struts, control arms and tie rod ends. These parts simply wear out overtime.

Newer vehicles that are being manufactured don’t have serviceable ball joints or tie rod ends anymore. They have these pieces called zerk fittings, which lubricate parts. 

Whenever our technicians are replacing steering or suspension components, we make sure that they’re serviceable.

Spark plugs are another part that, when failing, may lead to a knocking sound. They can also be the culprit behind engine misfires.

Other than components going bad, engine knock is sometimes the result of more complicated issues. 

Engine sounds may occur if the gas you put in your vehicle has a different octane level than it requires. Octane ratings are the type of fuel, such as regular, mid-grade and premium. It’s important to confirm and use the correct one.

Carbon deposits building up in the cylinders is another possible culprit. Having a fuel induction service performed regularly – we recommend them every 30,000 miles, depending on the type of vehicle you have – can clear out carbon build up and prevent engine damage.

What to do if you hear knocking sounds

If you hear knocking sounds – or any other strange noises – don’t be alarmed. 

It’s OK to continue driving it, but you should have it looked at by a mechanic or auto repair shop as soon as you are able to.

Putting off or ignoring the problem won’t cause it to go away. In fact, it will become worse the longer you wait to have it addressed. Having it checked out early on could prevent additional damage and unnecessary expenses.

Pay attention to where it’s coming from and when it occurs. Make sure to share that information with the mechanic or repair shop, as this can help them narrow down the issue.

HomeTowne Auto Repair & Tire is an authorized Michelin and BFGoodrich tire dealer located in Woodbridge, Virginia. Automotive repair services are performed on all makes and models, including oil changes, brakes, alignments, inspections, and computer engine diagnostics.