How Engine Timing Works

Your car engine consists of a number of rapidly moving parts, including a crankshaft, camshaft, pistons, engine valves, rods and pulleys. As the piston moves up and down, the valves move correspondingly, in and out. The crankshaft spins, and the connecting rods pull and push. All of this has to work in perfect harmony.

Different types of timing

There are two kinds of timing, cam timing and ignition timing. The cam timing regulates the valves and pistons, and the whole process is controlled by the timing chain or belt. If the timing is off, damage can occur. In some engines, called “interference engines,” the consequences can be especially bad. With this type of engine, the engine valves and pistons actually occupy the same space in the cylinder, but at different times. Since the intervals between the time when the piston owns the space, and the time when the valve owns the space is far less than a second, you can probably imagine the consequences if the timing is off. You could end up having to have your engine rebuilt, or even replaced.

If your cam timing is off, chances are you’ll know because your car will not be running well, if it’s running at all. Your ignition timing, on the other hand, can be harder to identify, but it’s easy to adjust. Ignition timing has to do with the four cycles of your car’s engine. The four cycles are:

  • Air gets sucked in by means of the intake valve, while the injectors deliver fuel.
  • The fuel mixture is compressed.
  • The spark plug combusts the fuel mixture, pushing the piston down.
  • The exhaust valve opens to let out the burnt fuel gases (the exhaust).

The most important thing is that the spark happens on time. If it doesn’t, you can end up with choppy idle, no power, or an engine that just won’t work.

You should never ignore engine timing problems, since if the timing is off, serious engine problems can be the result. If your car displays any of the symptoms of bad motor timing, consult a professional mechanic.


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

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 to Start a Diesel Truck
Starting Starting a diesel engine (https://www.yourmechanic.com/article/what-is-the-difference-between-a-diesel-and-a-gasoline-engine) is a lot different than starting a gas-powered engine. Whereas a gas engine starts when the fuel is ignited by the spark plug, diesel engines rely on the heat created by compression in the...
How to Replace a Power Steering Belt
Common signs of a failing power steering belt include a squealing noise and visible cracks, cuts, or nicks on the serpentine or drive belt.
How to Replace a Water Pump Belt
A water pump belt fails when the belt frays, cracks, or there is a burning rubber smell or squealing noise coming from the engine.

Related questions

Car is stalling while idling.
The most common problem with this condition is a faulty crankshaft position sensor. It is located near the transmission and controls ignition timing. if this is bad you may have the engine stall and will not restart. I would recommend...
Jeep shutting down below 1,000 RPMs
Your issue could have countless causes, from a vacuum leak to a faulty fuel pump. If the Check Engine Light is on, the first step is to retrieve the associated diagnostic trouble codes (DTCs). These codes serve as a starting...
Won't start and has spark, 49 psi in fuel pressure, and it ran when I parked the car. Why won't it start?
Hi there. Check the starter and see if is clicking when you turn the key. If the starter is clicking, then either the starter relay or the starter solenoid is not working. If there is no click and the starter...

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