Of the many things that can go wrong with an engine, timing chain jumping can be one of the most frustrating problems to have.
Depending on the motor, it can cause all sorts of problems. They require a lot of mechanical skill to replace.
One of the most common symptoms of a timing chain that has jumped is a rattling or ticking noise coming from the engine.
This noise occurs when the timing chain is loose and hits other engine components as it spins.
Additionally, a jumped timing chain can cause decreased engine performance, including misfires, rough idling, and issues with acceleration. In some cases, the engine may even fail to start altogether.
Quick Help Table
| Symptom | Diagnosis |
|---|---|
| Engine misfires or runs poorly | One or more cylinders may be out of time due to the timing chain jumping |
| Engine won’t start | Timing chain may have jumped so far out of time that the engine won’t start |
| Engine rattles or makes unusual noises | Timing chain may be loose or have jumped and is hitting other engine components |
| Check engine light is on | The engine control module (ECM) may detect that the engine timing is off and trigger a check engine light |
| Reduced engine power | The engine may not be able to produce as much power if the timing chain is off |
How Your Timing Chain Works
The timing chain connects the crankshaft to the camshaft(s). It keeps them running in sync. It ensures that the piston is close to or at top dead center at the moment of combustion.
If a valve is open or the plugs don’t fire at the right time, the air and fuel that have entered the combustion chamber are not going to ignite.
Most timing chains use a tensioner to keep them tight and to keep them from jumping.
If something happens to the tensioner, it can cause the timing chain to jump prematurely.
It’s always a good idea to really listen to your engine every now and then, so you know what the signs of a timing chain getting ready to jump are.
Symptoms of a Jumped Timing Chain
When a timing chain jumps, it can lead to serious engine damage if not addressed promptly. Here are some common symptoms of a jumped timing chain:
Unusual Engine Noises
One of the most common signs of a timing chain that has jumped is unusual engine noises. This can include rattling, clanging, or grinding sounds coming from the engine. These noises are usually more noticeable when the engine is idling or when the car is accelerating.
Engine Misfire
Another symptom of a jumped timing chain is an engine misfire. This happens when the timing chain is not properly aligned with the engine’s camshaft and crankshaft.
When this happens, the engine’s firing order can be disrupted, causing the engine to misfire or run poorly.
Poor Fuel Economy
A timing chain that has jumped can also lead to poor fuel economy. This is because the engine is not running as efficiently as it should be.
When the timing chain is not properly aligned, the engine has to work harder to produce the same amount of power, which can result in decreased fuel efficiency.
Check Engine Light
A jumped timing chain can trigger the check engine light to come on. This happens because the engine’s sensors are detecting that something is wrong with the engine’s timing.
If the check engine light comes on, it’s important to have the car inspected by a mechanic as soon as possible to prevent further damage.
Signs a Timing Chain is About to Jump
There’s not a whole lot that you can do for a motor once the timing chain jumps. It’s very important to catch this before it happens.
Listen Closely
The good news with chains is that with a good ear, you should be able to detect this coming.
The timing chain will begin to make a clacking sound. With the extra slack that develops in it, it’ll often clack against the timing chain cover.
Metal on Metal or Slapping Sound
It’ll sound a heck of a lot like a metal-on-metal washing machine.
That may be a strange analogy, but if you can imagine what that would sound like, you’re getting close to what a timing chain that is about to jump sounds like.
It’s Easiest to ID when Starting the Vehicle
At normal cruising speed, you’re probably not going to notice any sound at all. Far and away, the best time to identify the sound of a timing chain that is about to jump is going to be listening to it when you first start the vehicle.
If the timing chain is not metal, it’s really a timing belt, and they can be a lot more difficult to tell if they are going bad. Timing belts are a normal maintenance item on a vehicle. The best thing that you can do is have the vehicle timing belt service performed on schedule.
What You Should Do if the Timing Chain Jumps
If your timing chain has jumped, it needs to be fixed right away. It’s only a short matter of time before it’s going to jump again or break all the way. When that happens, your engine will likely need a complete overhaul.
It’s a lot of work replacing the timing chain yourself. Depending on the vehicle, you may need special tools made just for the job. Have the vehicle towed to a mechanic who can replace the timing chain for you.
Timing Chain Broken Symptoms
If your timing chain breaks, the most immediate thing you’ll notice is that the engine doesn’t run anymore.
The camshaft(s) aren’t going to turn, which means that only the lower part of the engine will turn.
In most cars, that would mean the crank and oil pump. Everything above that typically relies on the timing chain to turn.
If the timing chain is broken, the vehicle will not run. The real question is whether or not any permanent damage has occurred. The valves are going to get slapped by the pistons. This will cause them to bend.