Troubleshoot That Ticking Sound in Your Car's Engine

mechanic stethoscope
A stethoscope can help locate the source of unwanted engine noise. Getty

Do you hear a sharp tick tick tick coming from under the hood of your car? If so, there are a number of things that can cause this sound to originate from the engine. Some of them are troublesome and can be expensive to fix. Others are almost meaningless and can be easy to remedy if they need fixing at all.

First things first: Be sure your cat didn't steal your watch and is hiding out under the hood just to spite you. If you're sure this isn't the case, read on and let's see what we can figure out.

Listen Closely

A professional mechanic will often listen to your engine with a stethoscope. Yes, the exact same thing the doctor uses during your physical exams. You might wonder why you need a stethoscope—you can hear the ticking loud and clear from the driver's seat. That may be true, but it can be difficult to figure out exactly what part of your engine is making the sound. Even with the hood up and your head hovering over a moving engine, sometimes you can't tell for sure.

Unfortunately, you can't use the stethoscope method on a running car, so take some precautions before you begin. There are lots of moving parts to an engine and things can get ugly in a hurry if you don't keep clothing, hair, and fingers away from anything that spins or cranks. So once you remove your dangling jewelry, tie back your hair, and put on some old clothing, start scoping away.

Assessing the Damage

Two questions to ask yourself before you begin:

  • Is the sound definitely coming from under the hood?
  • Does the engine tick more in the morning, and seem to go away when you start driving or does it tick all the time?

Once you ascertain that the noise is definitely coming from under the hood, i.e., the engine, the first thing to check is your valves. This is a great test, because if your valves are making the noise, it may just be that you have a low oil level, or that you are long overdue for an oil change, both of which are easy fixes.

Hold the stethoscope on the cylinder head of the engine (check your owner's manual to see where this is located) and if what you hear is the exact same tick, only amplified, then one of two things are wrong: either it's the oil or it's a bad valve.

An engine low on oil will tick because not enough oil is making it into the engine. It will also "kick," or stutter when it runs. So, the first thing you should do is check your oil level. If you find that it's low, add a quart, and see if that fixes the problem.

If you find that your engine only ticks a little when you start up in the morning, don't sweat it. That's just the oil taking a few seconds to circulate through the entire engine after it drained to the bottom overnight.

If your oil is not low and the tick doesn't go away, or if it seems to get louder and louder over time, you should take your car to your mechanic to do a more thorough diagnostic test.