How Does a Timing Chain Work?

Your timing chain is absolutely essential to the operation of your vehicle. If it breaks, your car isn’t going to go anywhere, and you could end up with engine damage. So, how does the timing chain work, and what happens if it fails?

The basics

All piston engines have a crankshaft and a camshaft. The pistons move up and down, and the crankshaft delivers power from them and changes that power to a rotating motion. Then, the crankshaft drives the camshaft by means of a chain. At the other end of the crankshaft is the transmission, which is responsible for powering your wheels. The camshaft opens and closes the intake and exhaust valves. For each of the engine’s cylinders, the camshaft opens the intake valve, letting in a mixture of air and fuel. Then it opens the exhaust valve so that the burned fuel gases can be released. The valves have to be opened and closed at just the right time. This process is known as camshaft timing, or valve timing.

Timing methods

There are two ways to achieve valve timing. The first is the two gear method, and it’s the most reliable. A crankshaft gear simply meshes with a camshaft gear. These gears hardly ever fail, and are usually good for the life of the engine. This is the method used in most types of heavy equipment and big trucks. It’s also used in some cars.

The timing chain method is more common with cars, especially those of a certain age. Most modern vehicles are equipped with timing belts, although some still have timing chains. The timing chain can stretch, and that affects performance. Also, some vehicles have plastic camshaft sprockets, and if they overheat they can melt. Then the chain skips, and the engine stops. If the piston comes up at the same time as a valve fully opens, the valve could bend, and the engine could even be ruined.

Identifying a bad timing chain

You’ll usually notice some signs before you end up with a broken timing chain. The most common tip-off is a rattling noise coming from the front of your engine, particularly if it’s idling. Plastic chunks in the oil are another indication that a timing chain replacement might be warranted. If you find plastic in your oil following an oil change, the cam sprocket is likely ready to fail. When this happens, these chunks can end up in the screen of the oil pump, causing your car to lose oil pressure. And once the pressure gets too low, timing chain failure is pretty much inevitable.

The last thing you want is for your timing chain to fail, because it can cause a great deal of damage to the engine, sometimes even destroying it. So make sure that your timing chain is in good repair, listen and look for hints that all might not be as it should be, and have your mechanic replace it if necessary.


Next Step

Schedule Timing Chain Replacement

The most popular service booked by readers of this article is Timing Chain Replacement. YourMechanic’s technicians bring the dealership to you by performing this job at your home or office 7-days a week between 7AM-9PM. We currently cover over 2,000 cities and have 100k+ 5-star reviews... LEARN MORE

SEE PRICING & SCHEDULING

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Recent Timing Chain Replacement reviews

Excellent Rating

(171,627)

Rating Summary
161,099
5,644
1,174
834
2,876
161,099
5,644
1,174
834
2,876

Pete

16 years of experience
192 reviews
Pete
16 years of experience
Chevrolet Malibu L4-2.2L - Timing Chain Replacement - San Diego, California
Pete called ahead of time letting us know upfront that there might be more damage and that he couldn't guarantee that this would fix my problem but I opted to try anyways. He showed up right on time and finished the job an hour early. And he did a great job. My car is by no means in perfect condition (my fault, not his) but at least he got it up and running for me and that's all I can ask for at the moment. I would definitely use YourMechanic and Pete again.

Ben

18 years of experience
114 reviews
Ben
18 years of experience
Chevrolet Classic L4-2.2L - Timing Chain - Denver, Colorado
Great job again with Ben, Very good mechanic and I am a repeat customer.. Wonderful job done despite a huge unexpected rain storm. Thank you again!

Jared

21 years of experience
35 reviews
Jared
21 years of experience
Acura TSX L4-2.4L - Timing Chain - Aurora, Colorado
Jared arrived early for the initial consultation as well as to do the repair. He was friendly and knowledgeable. He took his time to get the repair right. He made a stressful situation more manageable. Would recommend to another in need of mechanical services.

Simon

27 years of experience
283 reviews
Simon
27 years of experience
Dodge Challenger V6-3.5L - Battery - Arlington, Virginia
Extremely courteous, and professional. Very helpful and knowledgeable.

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

Related articles

How Long Does a Serpentine/Drive Belt Last?
In order to operate, your car needs more than just a working engine and transmission. The “accessories” attached to the engine aren’t...
Why Timing Belt Replacements Can Be Tricky
Methods for changing a timing belt vary based on the type of belt. Service and maintenance should be done based on the manufacturer's recommendation.
How to Replace a Timing Cover
The timing cover protects the timing mechanism and has oil/coolant passages. If damaged, it should be replaced to prevent leaks and entry of debris.

Related questions

Is there a safe way for pregnant women to use seat belts in the vehicle?
Seat belt design has been dictated by a number of factors over the years, with pregnant women in vehicles being a major factor. Seat belts can be safely worn by a pregnant woman as long as both the shoulder and...
What is the Belt-Minder® system?
Your car has a lot of advanced features. One of those is the Belt-Minder® system. Basically, it’s designed to track seat belt use in your car and alert you to potential problems, keeping you and your passengers safer. The Belt-Minder®...
Squeaking whenever I turn the steering wheel, looks like moisture or Power steering fluid could be dripping on the belt ?
Hi there. It sounds like your power steering belt is loose. When power steering is being engaged such as slow or no speed turning, the demand increases on the pump and the pump is dependent upon the belt. If the...

How can we help?

Our service team is available 7 days a week, Monday - Friday from 6 AM to 5 PM PST, Saturday - Sunday 7 AM - 4 PM PST.

1 (855) 347-2779 · hi@yourmechanic.com