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Does Your Engine Make a Ticking Noise? Here's Why, and What to Do

Alex Palmeri
June 25, 2018

An engine that purrs can be very satisfying — it’s a healthy, reassuring sound. But if your engine has started making a ticking sound while running, it probably has you worried about both your car and your pocketbook.

Engine ticking noises are fairly common, and they can be either really bad news or not very serious, depending on the cause. In some cases, they can even be completely normal. Let’s run through some possibilities, starting with the most urgent.

Worst-case scenario: Low oil level or oil pressure

This is the most severe — and potentially costly — cause of a ticking engine. A bad oil pump, worn engine or low oil level can cause this or other engine noises

If you don’t have enough oil, or enough oil pressure, the top end of your engine will suffer first. Gravity will keep what oil there is further down in the engine.

If oil isn’t reaching the top of your engine, you’ll begin to hear a higher-pitched ticking or tapping noise. More often than not, this is coming from the engine’s valve train components like lifters, rockers, camshafts and cam adjusters. The timing chain can also make a ticking or tapping noise if oil pressure is an issue. 

What to do about an oil-related issue

Start by checking your oil level. Always do this with the car on a level surface. Pull out the oil dipstick, wipe it off, reinsert it and then pull it again. Ideally, the level will be close to (but not above) the full mark. 

If it’s low, top it up — but understand that you may have an oil leak. Check the level regularly to see if it drops, and keep an eye out for dripping oil under the car or under the hood, or tiny spots of oil on the back of the car near the exhaust. Just a few drops on the driveway could mean a much larger leak. The majority of oil seeps out only under acceleration, then eventually finds its way to the ground.

If the level is OK, checking your oil pressure is your next step. If you have a oil pressure gauge in your dashboard instrument cluster, make sure it’s at least 15-20 psi when the engine is warmed up and idling. 

On gauges without numbers, make sure it stays in the green. If you see the needle in the red, check the level immediately. If you don’t have this gauge, you may see a red oil warning light on your dash. If the oil level is full, you might just need the correct oil for summer. Either way, have your mechanic inspect your engine. 

If the oil level and pressure check out, you may have a worn or sticking engine part. You’ll want a mechanic to take a look.

One last possibility of major engine issues is called rod knock. This noise happens when there’s excessive play between the connecting rod and the crankshaft, causing metal-to-metal contact. It’s caused by oil starvation in that part of the engine. Rod knock is usually rhythmic, loud and increases with engine speed and load. 

If you have a sticking engine part, rod knock or other serious engine problem, the repair might cost more than the car is worth. Talk with your mechanic about whether you might be better off getting a new car instead.

Get it diagnosed by a professional
 

Other possible causes 

Bad spark plugs or wires

Spark plugs seal off each cylinder, so if one cracks or gets loose, you’ll hear a ticking noise. This is a common problem after DIY tune-ups. Your first step is a visual inspection of the spark plugs with the engine off and cool. 

Solution: Start by removing the spark plug wire and wiggling the plug. If it moves at all, it’s loose. In this case, pull it out and check the threads for damage. If they look OK, it’s possible the plug was not torqued correctly; you should reinstall it, following the manufacturer’s recommendations for tightening it.  

If the spark plug is cracked, try replacing it. The worst possibility here is that the spark plug has stripped the threads in the cylinder head. In this case, the cylinder head may need to be removed for repair or replacement. This is a major job that should be left to a professional.

Bad spark plug wires can also tick if the spark goes to ground — that is, anywhere on the engine block — instead of to the spark plug. An easy check is to watch the engine run in the dark. If you can see the spark, that means you have a bad wire.

Exhaust leak

Your car’s exhaust system is sealed up tight — any leak will cause the engine to sound louder. Many exhaust leaks, especially if they come from the exhaust manifold, can cause a ticking noise. 

The easiest way to determine if you have an exhaust leak instead of a major engine issue is to gently rev the engine while in park. Get it to about 2,500 RPM. If the noise goes away, it’s most likely an exhaust leak. If it remains, then oil pressure is the likely culprit. 

Exhaust manifold leaks can be caused by a blown gasket, loose or broken manifold bolts or studs, or even a cracked manifold. If you smell exhaust from the engine compartment and hear a ticking noise, you have a leak. Look for black soot around the manifold and downpipe connection.

Solution: Fixing exhaust leaks can be labor-intensive, especially on older cars with rusted hardware. This means it can be costly, too. If you have an older car, get an estimate and determine if the repairs will be more expensive than the value of the vehicle.  

Bad bearing or accessory

In some cases, a front engine accessory, pulley or bearing can cause a ticking noise. This can happen with air conditioning compressors, water pumps, belt tensioners or pulleys. 

Solution: To diagnose and narrow down which part is making the noise, you can run the engine and listen for the source of the noise with a mechanic’s stethoscope. But be very careful to keep the tool, as well as your clothing and hair, away from any moving parts. 

If the noise is up front but it’s not safe to test with the stethoscope, try removing the belt. You can safely run the engine for 30 to 60 seconds to confirm the noise has stopped. Shut off the engine, let it cool, and check each component individually. 

Your mechanic can also take care of this diagnosis, and can replace any failing accessories or other parts.

Engine fan or loose parts

Every engine has a fan of some type. If it gets damaged, this can cause a ticking or tapping noise. Or, in some cases, loose parts can rattle around and cause a ticking type noise. With the engine off, visually inspect the fan blades and shroud for damage. It may also be loose, so be sure to inspect the clips or bolts that hold the shroud on the radiator.  

Solution: Make sure to look over the heat and dust shields, metal lines or brackets, or anything else that can vibrate and come into contact with another part while running. Look at the bottom of the hood for contact marks. 

Ignition problems

Your engine’s cylinders are designed to fire at a very specific time. If this timing is off, it can create a pinging noise. This can be caused by poor-quality fuel, carbon buildup and various other problems. It will likely be worse if you are carrying a heavy load, or when accelerating after a red light or up a ramp.  

Solution: Try using higher-octane, Top Tier gasoline at your next fill-up, and see if that makes a difference. If not, this problem needs to be diagnosed by a professional mechanic. If your car says “premium fuel required” and you don’t use it, it will cost you in the long run. 

Purge valve, PCV valve or fuel injectors

Good news! These situations won’t cost you any money. Some ticking noises are totally normal and do not require any repairs. 

The purge valve on your car allows fuel vapors to be burned by the engine for emissions purposes. This valve will make a ticking noise at times. Likewise, positive crankcase ventilation (PCV) valves can tick or rattle at idle.

The fuel injectors on newer vehicles can also be loud and make a ticking noise. This is especially pronounced on cars with direct injection.

All of these situations are normal. Still, when you hear something new, check it out. Ignoring it always costs more in the long run.

 

Alex Palmeri

About the Author

Alex Palmeri worked nine years as a master technician at Mercedes-Benz of Chicago and is currently the foreman at a large fleet garage. He writes about automotive news, maintenance and racing, and runs a YouTube channel called Legit Street Cars.

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