1. Homepage
  2. »
  3. Cars
  4. »
  5. Vauxhall
  6. »
  7. Why is My Vauxhall Insignia Making a Knocking Noise?

Why is My Vauxhall Insignia Making a Knocking Noise?

Vauxhall Insignia knocking noise

Why is My Vauxhall Insignia Making a Knocking Noise?

A practical choice of vehicle, the Vauxhall Insignia is a favorite among families, as well as those who prefer spacious cars. Due to its larger stature, it would be easy to assume that the Insignia is bulky and loud to drive, when in actual fact it is the opposite. Many people praise this Vauxhall for its quietness in comparison to other cars of its size, not to mention that it is extremely comfortable. 

As with other cars, there are a few common problems with a Vauxhall Insignia, one of which is engine knocking. Most modern vehicles are exempt from the knocking noises that usually occur in older makes, but occasionally newer cars can suffer from it too. 

So, why exactly is your Vauxhall Insignia making a knocking sound, and how can you fix it? The following article will discuss the possible reasons and what you can do to help.

Why is my Vauxhall Insignia making a knocking noise?

Engine knocking can be off putting to a driver, that’s why it’s always best to get to the root of the cause as soon as possible. The knocking sound coming from your Vauxhall Insignia can occur for a variety of reasons. From fuel issues to internal engine problems, some of these issues can be solved by yourself, whilst others by a professional. We’ve put together a list of possible causes of that dreaded knocking noise. 

Fuel quality

filling up fuel tank
Photo by Envato Elements

If you’re pumping your Vauxhall with low quality, low octane fuel, this can cause a few issues for your engine. Pre-ignition can occur if your Insignia is not agreeing with the octane level of the fuel in its tank, this will cause damage to a variety of engine components, such as the piston rods. The excessive pressure built up before ignition is very harmful to your engine and can result in a knocking sound as internal parts become damaged.

Another issue with poor quality fuel is its ability to burn incompletely, leaving behind leftover carbon compounds. The buildup of carbon inside the combustion chambers, and on the walls of your cylinders, can again lead to a knocking noise. This time it is due to the little pieces of buildup being thrust around.

Air and fuel mix 

woman at fuel station picking up pump
Photo by Envato Elements

Leading on from the use of poor quality fuel, sometimes the knocking noise coming from your Vauxhall Insignia may be down to a bad mixture of fuel and air. There are optimum ratios when it comes to an air-fuel combination, and when this is out of whack it can cause a knocking sound. Again, this is due to both pre-ignition and a buildup of carbon.

Rod knock

checking car engine
Photo by Envato Elements

Most cars, the Vauxhall Insignia included, can suffer from premature wear within their engines. Usually, this leads to what is known as ‘rod knock’, in which the rods within the Insignia’s engine knock against the crankshaft as it rotates. Normally, these rods behave in this way due to a faulty bearing that connects the crankshaft and the piston rod. However, the overall premature wear can be down to low oil pressure or low oil levels. Oil is vital in keeping the inner components sufficiently lubricated and working perfectly – without it they will knock into each other.

Oil levels 

checking oil levels
Photo by Envato Elements

As explained above, oil is a very important factor in the health of your Vauxhall Insignia, as well as all other cars too. Low oil levels themselves can cause a knocking sound, mainly due to the under-lubricated engine components. Although, low oil levels and pressure can cause a variety of car issues and should definitely become a maintenance priority of Vauxhall Insignia owners.

Spark plugs

checking spark plugs
Photo by Envato Elements

If your Vauxhall Insignia has been fixed recently, or had a once over at a nearby garage, they may have replaced your spark plugs. It’s not uncommon for the wrong spark plugs to be fitted to your car, and this goes for all cars. The underestimation of how important it is to get the correct make and manufacturer can be pushed aside for cost reasons. However, this can cause engine knocking in your Insignia. As spark plugs are vital in determining the conditions in which the fuel will burn, incorrect spark plugs may provoke incorrect conditions. Ultimately, much like using a low octane fuel, deposits will build up and cause engine knocking. 

There is also a possibility that the spark plugs will fail altogether, which is not good for combustion, can damage your Vauxhall’s catalytic converter, and will cause a misfire.

Can you drive your car with a knocking engine?

Yes, you can drive your Vauxhall Insignia despite the knocking sound. However, it is always recommended to get your vehicle checked over at a garage or to follow some of our points above so as not to harm the engine further. 

How to fix your Vauxhall Insignia’s engine knock 

car rpm
Photo by CHUTTERSNAP on Unsplash

First of all, some simple tips to begin with. Ensure that your oil levels are adequate and topped up. After this, another tip is to check your spark plugs. Are they the right make and number? If not, they will need replacing and the correct ones fitted.

After you’ve checked the spark plugs and the oil, we suggest replacing your fuel with a higher octane count. Most cars are okay with the standard 87 octane level, but using premium fuel in your Vauxhall Insignia will help the overall engine health. 

As we explored earlier, deposit buildup in cylinders can be a major cause of your engine knock, so adding some cleaning additives to your fuel can help to get rid of those. Detergents such as injector cleaner can prevent and get rid of anything lingering in your Insignia’s engine. 

When it comes to replacing parts such as engine bearings and crankshafts, this should always be done by a trained professional. No need to do more harm to your Vauxhall. 


Keeping up with overall engine maintenance, such as topping up your Vauxhall’s oil, can really help to prevent recurring problems. If you find that your Vauxhall Insignia has a persistent knocking noise that just won’t go away, take it to a garage or dealership to be checked over fully.

Hopefully, we have helped you to understand a bit more about the knocking sound coming from your Vauxhall Insignia and how to fix it.