To Drive or Not to Drive: How and If You Should Start a Car with a Bad Crankshaft Sensor

How to start a car with a bad crankshaft sensor

The crankshaft in your vehicle, or virtually any modern internal combustion engine, is also called the crank. The crankshaft is the portion of your engine that causes your pistons to move up and down. The crank does this by rotating with the cylinders attached to the shaft, which is designed in an offset, or squared off zig-zag pattern to give the pistons varying push and pull times during the rotation. Your crankshaft is usually connected to your flywheel to aid in smoothing out the rotation.

Used car values can be fantastic but don’t show you the potential maintenance you will have to spend money on down the road because of the wear and tear you don’t have a full history of, even when you use a car finder with the complete log of upkeep and any potential accidents.

So, if you have a used car and suspect the crankshaft might need replacing, it is best to understand the warning signs of crank sensor problems now and consult your workshop manuals than to put it off and have a significant engine issue later.

The Importance of Your Crankshaft

Considering your crankshaft moves the pistons—a vital component of the engine—the crank itself is essential to the drivetrain and is absolutely necessary to drive your vehicle. The beginnings of issues with the sensor that times the crank can start with stalling out or with your check engine light coming on. Once the problem becomes severe, significant damage can happen to the engine if you continue to drive it.

Can I Start the Vehicle with a Bad Crank?

If you wonder if it is safe to start your car when the crankshaft goes, the answer is yes if it is the very beginning of the issue. Once the position sensor becomes compromised or if you have symptoms of a problematic crankshaft that you can’t ignore, do not drive your vehicle. How to start a car with a bad crankshaft sensor: turn on the ignition if and only if you have the check engine light on and minimal symptoms beyond that.

If your car misfired once or twice, or if you just started to notice uneven acceleration, it is drivable but time to take it to the shop. If the problems are more severe, driving can cause substantial engine damage that could cost you a lot more to repair. So, what symptoms should you keep an eye out for?

Symptoms of a Bad Crankshaft

When your crankshaft starts to go, there are a few telltale signs to look for. There can be a few other symptoms in rare situations, but the most common are as follows.

Difficulty Starting Up Your Engine

The most common sign of a lousy crank is getting your engine started. Trouble starting your car could be intermittent, or you may not be able to start it at all.

Uneven Accelerating

Another common sign that your crankshaft position sensor is not getting the correct input is irregular or unusually slow acceleration. This happens because adjustments can’t be made to the fuel injection or the spark timing with inaccurate sensor readings.


While intermittent stalling of your vehicle is frequently a sign of a wiring issue, it can also indicate a crankshaft position sensor problem. If the crank’s position sensor has its own wiring trouble, it too can cause your engine to stall. When your car stops amid traffic is can be not only frightening but dangerous. Stalling out can happen while idling at a stoplight, or it can happen while driving on a highway.

Engine Vibration or Misfires

If your engine begins to vibrate noticeably (more than usual) it can be caused by the misfire of your cylinders. This issue can also be the result of trouble with the position sensor on the crankshaft. The sensor could be providing incorrect information about the position of your pistons. This symptom could also be the result of timing from your spark plugs, so you will want to have that checked, too. If it is not the spark plugs, the crank position sensor is more likely the problem.

The Check Engine Light

While the check engine light turning on could be from several engine issues, it will frequently illuminate with crankshaft sensor troubles. If you have any of the other symptoms, such as uneven acceleration, misfires, stalling out, or difficulty starting your vehicle along with the light, take it to a mechanic right away. The shop should be able to scan for trouble codes to help pinpoint the issue.

How Much Does It Cost to Repair a Crankshaft?

If you do need to have your crank or the position sensor repaired, it is not always the cheapest fix on a vehicle. The cost will depend significantly on both the model of your car as well as your location. In some situations, a crankshaft repair can cost around $200 with labor tacked onto that. With other types of vehicles, it can cost thousands of dollars.

The average price of repairing your crank runs between $280 and $400 but can be several hundreds of dollars more if you have a luxury car, a vehicle that is tricky to work on or live in an expensive area.

Replacing Your Own

If you are excellent at working on vehicles yourself, it is possible to change the crankshaft sensor on your own. You will just want to do thorough research on how to do this correctly, and if possible, how to replace one on your specific car. If the replacement is not done well, it can cause the problem to arise again or damage your engine more in the long run.

Can I Wait to Fix My Crankshaft?

New car prices can be expensive, so unless you want to pay to replace your whole engine or buy a new vehicle, putting off a crank repair is not advised. The cost of fixing a crankshaft might be a few hundred dollars, but that certainly outweighs the price of a full engine overhaul, which can run thousands of dollars.

Stalling out on a freeway is also extremely dangerous, and getting in an accident will hike your cost of auto insurance, even if you are lucky enough to walk away unscathed. Even if you do not damage your engine by riding around with a crank that is failing, you put yourself and others in hazardous situations if you need to make a left turn or merge at a certain speed and your vehicle just won’t accelerate the way it needs to.

Crankshaft Repair

If the symptoms of a crankshaft position sensor issue are very noticeable, it is worth the cost to call a towing company or roadside assistance, such as AAA, and have them take your car to the mechanic shop instead of putting more miles on a faulty crank and the pistons. The code for a failing crankshaft sensor is P0335. When you get it to a shop, request a “check engine light diagnostic” to make sure that is the issue, and they are not going to charge you for another repair that could be unnecessary.