The timing system in your car is responsible for the proper opening and closing of valves and the lifting of pistons. The engine can work smoothly and efficiently in that case only if the timing is normal. If the timing belt or chain is off a tooth, the system will not do its job correctly. The valves will open late or early, the pistons may even hit the valves or at least won’t move at the needed time.
In short, when the timing is off one tooth, your engine works harshly or stalls, doesn’t have power, consumes a lot of gas, and throws different codes and warning lights. You will certainly feel that something is wrong with the timing system if the belt or chain is off a tooth. Such a situation doesn’t leave you any other chance but call for professional help.
Here’s what I will cover in this article:
- Common symptoms of the timing being off one tooth.
- How does the timing system work and why is the preciseness so important?
- Why can the timing system be off one tooth?
- How to repair and prevent this thing from happening?
Symptoms of the timing system being off one tooth
It’s impossible to ignore such a problem because it will affect almost every aspect of your engine’s work. First of all, the engine will completely lose its efficiency and nothing will make it work properly but the adjustment of the timing system.
Although the symptoms are pretty clear, they all can show up when there are other problems with the engine. So, once you encounter these symptoms, don’t take the engine apart to see if the chain or belt is off a tooth. Inspect the engine correctly to make sure that it has problems exactly with the timing system.
Here are the most common symptoms:
- Engine idling poorly. Bad idling is the first symptom because now the intake and exhaust valves are opening and closing at the wrong time. The engine vibrates and works harshly.
- There is much less power in the engine. You just can’t accelerate the vehicle. Once you press the gas pedal, the engine sputter and may even stall. You can drive only by gently pressing the pedal.
- The engine may stall at intersections. Once you release the gas pedal, the engine may stall being unable to maintain the needed RPM by means of the ECU and its signals.
- You may see the check engine light. In the majority of vehicles, the ECU controls the correlation between the position of camshafts and crankshaft and it may throw a code like P0017 or some other to show that there is a problem in this correlation.
- Rattling noise. This is especially true for engines with timing chains but belts can also cause some rattling noises. This is an additional symptom proving that the problem is exactly in the timing system.
- Misfiring engine. You may also get other codes in the ECU because cylinders will start misfiring. This also adds to the problem of power loss.
- Hard starting. Usually, it’s very hard to start the engine with the timing off even if it’s just one tooth. You will crank the engine for a long time but it will not start or will eventually start and work harshly.
It’s not necessary that you will encounter all these symptoms in your vehicle at once. Some engines may be more sensitive to timing problems than others. But anyway, you will not ignore this because driving a car with the engine timing off is not the most pleasant activity you’ve ever had in your life.
If two or three symptoms out of the list above are happening in your car, you should follow the instructions given below to avoid fatal engine damage and other issues.
A short insight into how engine timing works
I can’t describe all the possible symptoms of what’s happening with the car when engine timing is off one tooth. But I can give you an overview of how the system works and you will deduct everything on your own.
So, the timing belt or chain basically connects the camshafts and the crankshaft. Camshafts are two shafts in the engine head that control the opening and closing of the valves. The crankshaft is responsible for moving pistons that attach to it and it’s located in the bottom part of the engine block.
When the piston in a certain cylinder goes up, all valves should be closed so that the piston created the needed compression. Then the spark plug ignites the fuel in the combustion chamber and the fuel burns in the compressed chamber. It pushes the piston back down to the engine block and creates energy.
When this happened, the exhaust valve opens and lets the waste go out of the engine, then immediately the intake valve opens and lets some air-fuel mixture enter the chamber. Then the process repeats.
So, if the timing is wrong, one of the valves may be open when the piston goes up and there won’t be any compression. This will lead to a misfiring engine because it just can’t efficiently burn fuel. Also, the chamber will obviously not get the needed amount of air-fuel mixture at the correct time.
Why is the timing system off one tooth in your engine?
Once you notice that the engine works harshly, doesn’t accelerate the car, and can’t hold the stable RPM when idling, you may immediately think of engine timing. And you’ll be right.
But why could this happen? There are numerous possible reasons for this issue. I will concentrate on the most common ones:
- The timing belt or chain has already stretched too much and can’t do the job anymore. It happens after about 60,000 miles with belts and 80-100 thousand miles with chains.
- The tensioner is stuck or broken. There is a special tensioner that helps the chain remain at its optimal tension. If it stops working, the belt may easily jump.
- Huge load on the engine. If you overload the engine like towing something heavier than the towing capacity, you may find the belt or chain jumped one tooth or more.
- Damaged pulleys or other components. The system of engine timing consists of several pulleys that let the belt rotate in the needed area and do its job. If something happens with the pulleys, the belt may jump.
- Water pump failure. In the majority of engines, the water pump is driven by the chain or belt. If the pump is suddenly stuck, you may find the belt broken or it may jump.
These are just the most obvious reasons why your belt or chain may jump or break when you drive your vehicle. Unfortunately, there are other issues. For example, in chain-driven engines, poor quality of oil can be the reason. Also, low-quality belts or chains can be the reason for failure.
You should buy high-quality parts for repairing and maintaining the engine. Bad tensioners, belts, chains, pulleys, or water pumps may quickly lead to fatal engine failure.
Repairing your vehicle after the timing system jumped one tooth
If you don’t have any experience as a car mechanic, you shouldn’t try repairing your engine after such a problem happened. The problem is that the timing system is very tender and sensitive to any actions of an unskilled mechanic. If you do something wrong, the engine may just not start or even get a worse problem that will cost you a fortune to solve.
So, here’s what you should do when you suspect that the timing is off one tooth:
- stop the vehicle in a safe place – don’t drive it anymore;
- find the way to get your car towed to a trusted repair shop or to the dealership;
- ask a mechanic to inspect the engine timing system, and describe all the symptoms;
- get a professional opinion on what happened and ask about the price of repair;
- in most cases, you will need to change the timing belt or chain after this;
- I strongly recommend replacing the entire timing chain or belt kit to avoid such problems in the future.
You shouldn’t forget that all engines need timing system maintenance. Even if the manufacturer of your car doesn’t set the interval for timing chain replacement, you should replace it between 100,000 and 120,000 miles (or sooner if it rattles or jumps). For belts, this interval is 40,000-60,000 miles.
If you have your car inspected in the dealership, you should know that the price of labor will be huge there. Maybe, you will want to take your car to a good repair shop after the inspection. At least, you will know for sure what happened to the vehicle.
Final thoughts
You should be very careful when it comes to the timing system of your engine. One problem with this system may immediately kill the engine and make its repair cost more than the remanufactured engine costs on the market.
To avoid problems with timing belts and chains, you should replace them as often as stated by the manufacturer or even more often. If there is no stated interval, you should use the general intervals that I’ve mentioned above in this article.
Don’t drive your car if you suspect that the timing chain or belt has just jumped a tooth. This may kill the engine completely.