All modern vehicles are equipped with a camshaft position sensor. Vehicles, such as those from the 50s and 60s, do not have camshaft position sensors and don't require them for operation at all. In modern vehicles a camshaft position sensor is a part of your vehicle's electrical system and it monitors the position of your camshaft, as the name suggests. Working in conjunction with the crankshaft position sensor it lets your ECU know what stroke the pistons are on in your engine. That said, if your camshaft position sensor has begun to fail or is not working at all is it possible that you can still drive your car safely? The answer to that is both yes and no. Take a look at what a camshaft position sensor does so it's easier to figure out exactly how it will affect the operation of your vehicle when it's not functioning the way it's supposed to.
What is a Camshaft Position Sensor?
The camshaft position sensor is a fairly small device that you'll find under the hood of your car with the purpose of monitoring the position of the camshaft in your vehicle. The camshaft and the crankshaft of your vehicle have to operate in precision time in order for your engine to work. While the timing is controlled by your timing belt or timing chain, the position of your camshaft is monitored and adjusted thanks to signals from the camshaft position sensor which are sent to your car's computer. As the crankshaft rotates, the pistons rise and call in the cylinder. The camshaft rotates as well and opens and closes the valves. When everything is aligned correctly as the pistons rise the valves open and the combustion reaction then forces the pistons back down again. This happens in sequence throughout the cylinders of your engine over and over again for finding power that makes your car go forward.
The precise timing of all of the elements required for this to work properly can go awry eventually. The fuel and air mixture must be injected into the chamber at the exact right moment, the spark needs to ignite at the exact right moment, the valves need to open at the exact right moment and the pistons need to rise at the exact right moment. As you can see, there's a lot going on in here. The camshaft position sensor is another tool that helps ensure everything occurs when it needs to occur. If the timing goes wrong, the camshaft position sensor can send that data to your computer so it can make adjustments. Whether that means the spark will occur earlier or later in the sequence, whether that means you need to have more fuel added to the fuel-air mixture, or maybe less, it all depends on how your engine is operating.
Without the camshaft position sensor, your car's computer will have less accurate data on which two perform its overall functions. That will mean things will be less precise overall, and you'll be more likely to experience problems like rough idling, engine misfires, and so on.
Locating the camshaft position sensor in your engine it's not the easiest job in the world if you're not familiar with what it looks like. There's no standard position for it and it will change based on the make, model, and year of your vehicle. Generally, you will find it somewhere around the back of the cylinder head or next to the engine block. You can Google the camshaft position sensor for your vehicle to get a look at it so you can help identify where it might be under the hood of your car.
What Happens When a Camshaft Position Sensor Goes Bad?
If your camshaft position sensor starts to go bad there are some signs you will notice in your vehicle to alert you to the problem. While any of these symptoms could be indicative of another issue in your vehicle if you're experiencing more than one of them then you definitely should consider getting your camshaft position sensor looked at, just in case.
Jerking or Surging
If your camshaft position sensor fails while you're driving then the engine may lose power which cause your vehicle to lurch and jerk unexpectedly. This happens because the powertrain control module isn't getting the right signals from the camshaft position sensor any longer. Since the PCM controls the fuel injector and the ignition system controls it won't be able to send the correct information to them which in turn means that you're potentially not getting combustion reactions happening when they're supposed to.
If your engine stalls frequently you could also be a problem with your camshaft position sensor not working. Because the camshaft position sensor could potentially be sending a faulty signal to the fuel injectors and end up not delivering fuel to the combustion chamber as a result. Obviously with no fuel injected, combustion can't occur and that will mean your engine could potentially lose power to stall out on you. While this would certainly be an annoying issue to deal with if it happens on start-up in the driveway, it would be extremely inconvenient and perhaps even dangerous if it happens on the road while you're driving.
If the camshaft position sensor doesn't send the correct signals to your PCM, it may not even understand that you're trying to get your car started. That means the spark plugs will not create the spark needed for the ignition process to occur and you'll be unable to even get your engine started in the first place. This is a more extreme problem, and definitely means you'll have to get it fixed if you want to drive your car again.
In some models when the camshaft position fails then the transmission may lock up on you. This could prevent you from getting into gear at all, or it could happen while you're in one specific gear and prevent you from leaving that guy. That means you could be driving and get stuck in first gear which will drastically limit your performance and speed. It could also become a serious safety issue if you're on the road when it happens if you're no longer able to maintain your vehicle at speed to match the flow of traffic around you.
If the camshaft position sensor is giving the incorrect signals to your car's computer then you may not be experiencing fuel injecting at either the right time or in the right quantities into the combustion chamber. That in turn means that the vehicle can be performing at a greatly reduced power and efficiency, similar to what happens when a car goes into limp mode. When this happens, you will not be able to reach the speeds that you intend to travel at, it may end up driving at only a fraction of your normal speed. Again, this is a serious problem if you are in traffic on the highway for instance and you're not able to travel the speed you intend to travel at. When this happens, you need to safely get off the road as soon as possible.
Bad Gas Mileage
As we've seen, the problems with your camshaft position sensor can lead to a number of issues that cause your fuel to be injected incorrectly into the combustion chamber. Either the quantities will be off, or the timing will be off. Both of these problems will end up wasting fuel, which will cause you to head to the gas station more often to fill up. So not only are you suffering for performance at this point, you're also having to spend more money on gas to have a poorly performing vehicle.
Check Engine Light
This is one of the clearest indications that something is wrong with your vehicle, it's also one of the most frustratingly vague symptoms as well. A check engine light can pop out for any number of reasons, and a bad camshaft position sensor is just one of dozens if not hundreds. However, the upside of this is that it is a clear indication something used to be checked out, so you at least know that there is an issue to be dealt with.
One of the best things you can do for yourself if you're interested in how your car runs is to get an OBD2 scanner. The onboard diagnostic scanner is the tool that a mechanical will use when the check engine light comes up on your dashboard to diagnose the problem and narrow down what it is. You can get an OBD2 scanner on a site like Amazon.com for about $30 to $40. When you plug it in, it will give you a more specific read out of what the problem is. In this case it would warn you that the camshaft position sensor is the root of the problem. And if it's not the problem, it will direct you elsewhere so you don't have to second-guess what might be going on in your vehicle. An OBD2 scanner doesn't fix any problems for you, but it does point you exactly where you need to go and that's why they're pretty helpful to have.
Cost of Replacing a Bad Camshaft Position Sensor
If you know that your camshaft position sensor has gone bad on you, then it's in your best interest to get it repaired as soon as you can to avoid any of the problems that were mentioned. Luckily, a camshaft position sensor is not a very expensive item. In fact, if you go to a site like AutoZone right now you can probably find one for around $20. Keep in mind that these are specific to the make and model of your vehicle, and while $20 is on the low end of the scale some of these can get up to around $300. If you have a more expensive, high-end vehicle then you can expect that you may have to spend more money on your camshaft position sensor.
If you’d rather go to a mechanic to get this job done instead of handling it yourself, then the cost is going to reflect the labor involved in getting this part fixed. As we said, it's a pretty easy part to find and you can actually handle this job on your own probably. That said, if you want a mechanic to get the job done for you so you can ensure that it's done correctly and quickly, then you will probably end up paying around $125 to $200 to get the job done. Again, this will vary greatly depending on the make and model of your vehicle and you can probably expect it's going to cost a lot more to get this part replaced on a McLaren than it is on a Toyota.
Can I Replace My Own Camshaft Position Sensor?
Like we said, this is a fairly easy repair job to handle on your own if you're so inclined. One of the hardest parts of doing this on your own is actually figuring out where the camshaft position sensor is in your engine. Once you have located it, replacing it is simply a matter of popping the old one off and then sticking the new one on. It's not very involved or detailed, so you shouldn't have too many problems with it if you can handle jobs like changing a tire or swapping out an oil filter.
If you're not one hundred percent sure on what to do, you can always Google a walkthrough or a video that shows you what to do to replace a camshaft position sensor. You'll definitely save yourself at least $100 if you do this on your own rather than head to a mechanic to get it done.
Is it Safe to Drive Without a Camshaft Position Sensor?
Again, when you want to know if a car can run without a camshaft position sensor, the answer is yes or no. Your car will not shut down without the camshaft position sensor present. However, as we showed, there are a number of dangers to driving without one. So, while you can drive your car, and yes, a car can run without a camshaft position sensor, it's not a good idea. These parts were made for a reason and they helped improve the overall performance and safety of your vehicle.
The Bottom Line
If your camshaft position sensor fails on you it doesn't need to be fixed, but it should be fixed. There's no reason to let something like this go especially considering how affordable it is to get it repaired if you want to handle the job on your own. Your car can run without a camshaft position sensor, but we do not recommend it.