Car Engine

Why Is My Engine Making A Ticking Noise When Idle?

Mike Cross
Updated Oct 17, 2020

Your engine can make some strange noises. And it shouldn’t come as a surprise. But when you hear a ticking noise while your engine is idling, should you worry? And if it does tick, what would cause it? In this article, we’re going to talk about the potential mechanical issues you may have if your engine begins to tick.

Why Is My Engine Making A Ticking Noise When Idle?

Why Is My Engine Making A Ticking Noise When Idle?
Why Is My Engine Making A Ticking Noise When Idle?

When a problem exists, the first question you always ask is why is it happening?

If your engine is making a ticking noise, there’s a good chance that one of your reciprocating components might be having an issue. This means you can rule out any of your rotating components like your bearings or accessories.

That’s because it will make more or a whirring or whining noise if something is wrong with it. Your reciprocating components consist of your pistons, rods, pushrods, and valves. These are your components that will make those ticking, clicking and ratchet-type sounds.

What Could Be Causing This?

The exact cause can only be determined by a mechanic. However, one of the following issues may be the reason why your engine is ticking:

  • Low oil level.
  • Valves that are out of adjustment.
  • Rod knock or lifter tick.
  • Engine Wear (including operating noise).

Low Oil Level

Oil dipstick and oil cap
Oil dipstick and oil cap

A low oil level can cause a ticking noise in your engine because the valvetrain components are not properly lubricated. If you hear a tick, check your oil immediately. If you have a low oil level, then you’ll need to put motor oil in your vehicle. However, you shouldn’t settle for just any ordinary motor oil. The type of motor oil, be it conventional or synthetic, depends on the vehicle you may have. If your vehicle has a high tech engine, get a full synthetic oil. If your vehicle’s odometer is north of 75,000 miles, then you should choose a motor oil that is designed for high mileage.

Valves Out Of Adjustment

A noisy valve train is one of the common causes of an engine ticking. Your valves are suppose to open and close every two times your engine spins around. With a overhead cam engine, the camshaft lobes depress the valves. In single cam engines, the cam actuates the push rods that open the valves by moving what is called a rocker arm. The distance from the cam or pushrod needs to the valve needs to be precise because your valves move very quickly and at short distances. The distances are controlled by shims or other adjustments. When normal wear occurs, the distances can be moved out of tolerance. You can usually hear a ticking noise if there is excessive play in these components. This clearance can be removed by either replacing the shims or adjusting the rocker arm.

Rod Knock Or Lifter Tick

A rod knock happens when your engine ticks along with the engine RPM and the ticking sounds slow down. A rod knock can be caused by a bad bearing in your connecting rod. As it wears out, the bearing will allow movement and play a tapping or clunking sound depending on how badly worn it may be. The sound of the rod knock will change when the RPM changes, but it won’t change with engine load or temperature. The only cure for a rod knock is rebuilding the motor itself.

Engine Wear (Including Operating Noise)

Finally, the tick in your engine just might be a normal thing. It can be based on how the engine is designed or it can be associated with the typical wear. However, there’s a difference between what makes an engine tick normal and what is considered a problem. The tick may be a normal thing if you have a fuel injected car. That could be the sound of your injectors firing off. Your fuel injectors are small valves that quickly open and close allowing fuel to be injected with the air your engine is bringing in. If you have a vehicle like a Subaru, your vehicle will have these types of injectors that you can actually hear while your car is sitting at idle. The sound may be equivalent to a pencil tapping hard on a desk.

One tick can be caused by an exhaust manifold leak. If you hear a ticking noise, it could be that high pressure exhaust is escaping a crack that has formed in the manifold. Or there could be a leak in the gasket when the engine is at idle or at a low RPM. While the tick is not dangerous for your vehicle, the smart thing to do would be to get it fixed as soon as possible. This way, the exhaust gases should stay where they are supposed to.

So Should You Worry?

The short answer: it depends. If you know that your vehicle has fuel injectors, odds are that the tick in your engine is perfectly normal. If you have no clue if your vehicle has them, it takes a little bit of digging online to figure out what some of your vehicle’s inner workings consist of. When in doubt, you can always consult a mechanic. They will have a better idea of how an engine of certain vehicles should sound.

If there is indeed an issue with your engine, it should be taken care of immediately. A mechanic will diagnose any potential problems such as checking the valve trains or the rocker arm to see if it’s properly working. If you haven’t checked the oil, they might do so to determine if a low oil level is the culprit. Or at least, you should use bluetooth obd2 scanner to test first to find problem. 


A ticking noise in your engine can be normal. That of course depends on the engine itself. If you do hear a ticking and you’re not sure what exactly could be the cause, do not hesitate to get it looked at. Sometimes, the diagnosis may yield that it might be not at bad as you think.

Mike Cross
Life is too short to drive with stock audio

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