Knock, Knock: Finding And Silencing The Rattle In Your Engine

Posted on: 14 January 2015

As a car owner, you're likely to hear clicking or rattling under the hood of your car at some point. If this sound is new to you, finding its origin can be difficult. In most cases, sounds like this are the result of rocker arms rattling or the rods sticking in the engine. For engines without rockers, the sound could be stuck valves. Here are some tips to help you track down the source of the noise and fix it.

Gathering Supplies

In order to determine what caused the problem, you'll need to have a complete wrench set, as well as a variety of screwdrivers. Since you'll have to open the valve cover, you will also need a valve cover gasket and some fresh oil. Depending on the actual cause of the problem, you may also need an engine flush kit, engine detergent and penetrating oil.

Check the Oil

Sometimes, dirty or low oil levels will cause ticking and rattling in the engine. This is because insufficient or contaminated oil can cause the valves to stick and may cause scoring in the lobes. Change your oil and replace the filter, making sure that you fill the oil completely. If the engine oil was the problem, this will eliminate the noise.

Examine the Rocker Arms

First, you need to remove the valve cover. You'll need a socket set to remove the bolts securing the cover in place. Once you move the cover out of the way, you'll be able to see the valve springs and rocker arms. The rocker arms should all be the same height. If one is sitting lower than the rest, remove the valve spring and replace it with a new one. This should stop the rocker arm from rattling.

Clear Out Buildup

Pour penetrating oil into the valve guide while the engine is running. This will distribute the oil throughout the space. If that quiets the noise, it's a sign that there's buildup on the valve stem. Flush the oil out of the engine, and opt for a higher quality oil when you refill the engine.

Tighten the Valve Springs

Turn the valve spring with a wrench to tighten it. If tightening the springs eliminates the noise, that's a good sign that you may want to replace the valves. If one is damaged or worn, it's best to replace them all.

Install a new valve cover gasket when you replace the valve cover. Scrape any residual material from the old one off the flat surfaces of the valve cover before you secure the new one in place so that you can ensure proper adhesion.

With the tips presented here, not only can you narrow down the source of that elusive engine rattle, but you may be able to fix it on your own. If you can't quiet the engine on your own, look for an auto repair or car care shop that can help you straighten it out. For more information of what could be causing the rattling in your car, check out