Crankshaft

Every time you drive, there’s one crucial component working behind the scenes to keep your vehicle running: the crankshaft. You won’t see it during your daily checks, and it rarely makes a sound when it’s healthy, but it plays one of the most important roles in your engine’s operation.

The crankshaft is built to last, but like every part of your vehicle, it depends on regular servicing and the right oil to stay in good working order. Without it, performance drops, and in severe cases, your engine could be at risk.

At Roade Main Garage, we help drivers in Northampton, Milton Keynes, and the surrounding areas protect key components like the crankshaft through reliable, manufacturer-level servicing. In this guide, we’ll break down what the crankshaft does, how it works with the crankshaft position sensor, and what warning signs you should never ignore.

Crankshaft Basics: What Is It?

Let’s start with the basics. The crankshaft is a long shaft located near the bottom of your engine. It’s housed in a protective shell called the crankcase, and it sits just above the oil pan, which stores the engine oil.

Its primary job is to convert the up-and-down motion of the pistons into a rotating motion. To handle this demanding role, the crankshaft is engineered with:

• Counterweights to minimise vibration
• Internal oil channels (oilways) to distribute lubrication
• Highly polished surfaces to reduce wear

While it’s built for durability, it can still wear out or become damaged, especially without using the correct oil and regular servicing.

Crankshaft Basics: Role

Every time your engine completes a cycle, the crankshaft converts the up-and-down motion of the pistons into rotary energy. This rotation powers the clutch, gearbox, and your vehicle’s wheels. At the same time, the crankshaft drives the camshaft via a timing chain, belt, or gears, ensuring precise valve timing. 

This rotary energy is also what your car uses to power auxiliary components such as:

• The gearbox
• The alternator
• The water pump
• The air conditioning compressor

In short, the crankshaft turns the engine’s energy into smooth, rotational motion. It’s the central mechanical link between combustion and movement.

What Might Go Wrong?

Although crankshafts are made to last, they aren’t immune to damage. If you have taken your vehicle for its service at the recommended intervals, problems are unusual. Although crankshaft failure is rare, it’s usually serious and expensive when it does occur.

That said, in many cases, problems arise not from the crankshaft itself, but from the crankshaft position sensor.

Crankshaft Position Sensor

The crankshaft position sensor is an electronic sensor mounted to the engine block near the crankshaft. Its job is to track the exact position and speed of the crankshaft and send that information to the Engine Control Unit (ECU).

The ECU uses this data to determine:

• When to fire the spark plugs
• When and how much fuel to inject
  

If the sensor fails or starts giving inaccurate readings to your ECU this can result in poor performance, engine stalling, or even a no-start condition.

That’s why the crankshaft position sensor is considered just as essential as the crankshaft itself in modern engine management systems.

Crankshaft or Sensor Faults: The Symptoms You Shouldn’t Ignore

When the crankshaft or its sensor is struggling, your vehicle may show subtle (or not-so-subtle) signs. Here’s what to watch out for:

• Difficulty starting the engine – The ECU needs accurate crankshaft data to start the ignition sequence. If it doesn’t receive it, the engine may crank but fail to start. If you do get the engine going, the issue can often reappear the next time you try to start up, as the system can no longer rely on previously stored sensor data.
• Rough idling or power loss – A failing sensor can throw off timing and fuelling, which can cause the engine to idle unevenly, lose power, or accelerate poorly.
• Check engine light – An inconsistent or missing signal from the crankshaft sensor usually triggers the dashboard warning light. Ignoring this could lead to bigger problems.
• Temperature-sensitive faults – High engine temperatures can interfere with sensor function, causing intermittent stalling or no-start issues until the engine cools.
• Unusual knocking or vibration – If you hear strange noises from your engine or feel heavy vibration, it could be a sign of crankshaft wear or bearing failure. This needs immediate attention from professional experts, like our team at Roade Main Garage.

Catching these symptoms early can prevent more costly repairs later. A professional diagnostic check is the best way to pinpoint the cause.

Keeping Your Crankshaft in Top Condition

Maintaining the crankshaft doesn’t require anything fancy! Here’s how we help you keep things running smoothly at Roade Main Garage:

1. Stick to Routine Oil Changes

Following your vehicle’s oil service intervals is key to crankshaft health. Clean oil:

• Reduces friction between metal surfaces
• Keeps temperatures stable
• Removes contaminants

We use manufacturer-approved oils for every service at Roade Main Garage, ensuring your engine receives full protection.

2. Use the Right Oil Every Time

The correct oil grade makes a big difference. Using oil that’s not the specified type can:

• Cause premature wear
• Not offer bearings sufficient protection 
• Lead to engine damage
  

At Roade Main Garage, we always match your oil to the exact specification set by your car’s manufacturer.

3. Book Your Full Service On Time

During your scheduled service, we inspect and replace your oil, as specified above. It’s the most important move you can make as a car owner!

A full annual service is your best defence against crankshaft problems and many other avoidable engine faults.

Count on Us to Keep Your Car in Top Condition

At Roade Main Garage, we understand that prevention is better than repair. Whether you’re coming in for your annual service or you’ve noticed something unusual under the bonnet, our team delivers reliable, manufacturer-level care every time.

We’re proud to support drivers across Northampton and Milton Keynes, and every repair or service is backed by our 12-month parts and labour guarantee. Our dedication to great service is reflected in our {{average-rating}} star Google rating from {{review-count}} satisfied customers.

Here’s what you can expect when you book with us:

• Transparent pricing with no hidden charges
• Genuine or OEM-quality components for every repair
• Advanced diagnostic tools to identify issues early
• A trusted team that puts your safety and satisfaction first
  

(OEM stands for Original Equipment Manufacturer. When it comes to vehicle parts, this means the parts are made by the same company that produced the original parts for the vehicle manufacturer)

If you’re concerned about your crankshaft, sensor, or engine performance, give us a call, we’re always happy to help.

📞 Ready to book or need expert advice? Call 01604 862262 and speak to a member of the team at Roade Main Garage. We’ll make sure your vehicle gets the care it deserves. No guesswork, no shortcuts.

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