While Saab models are not in active production anymore since the early 2010s, the brand has a dedicated fanbase. Saab produced cars that are safe, fuel-efficient, and have good handling. Even though they are no longer actively made, used Saab vehicles can still be purchased on the pre-owned market.

Even when properly maintained and with no excessive usage, your Saab is still prone to several issues. One problem that drivers occasionally encounter is a knocking sound under the hood of their car. You may be wondering what it means and if you should be concerned. We can help you get a good idea of what is happening underneath the hood of your vehicle.

The Basics You Should Know If You Hear Knocking Sounds

A knocking sound is very annoying and can get on most people’s nerves quite quickly. Beyond just a verbal annoyance, however, is a clue from your Saab that something is wrong. This knocking sound can vary greatly, meaning that the issue can range in terms of severity and the potential to cause long-term damage to your car. In all cases, though, you will undoubtedly want to diagnose and identify what is going on.

Below are a few of the most common issues that can cause knocking noises:

  • The rod bearings in your car are worn or damaged: The purpose of rod bearings is to hold the spinning shaft of your vehicle and to provide support. If your bearings are damaged or worn, this can cause a knocking sound.
  • There is an issue with the air/fuel mixture in your engine: If the fuel injector, fuel pump, airflow sensor, or oxygen sensor has failed, this could lead to an imbalance of air/fuel mixture in your engine. This imbalance is called a lean air/fuel mixture, which means you have too little fuel and too much air. This combination can lead to engine knock due to the mixture not burning fast enough and causing detonations.
  • The timing of your engine is off, causing misfires: A computer system controls modern cars to provide information to your engine. If the instructions for when the timing of your spark plugs fire is off, this can cause your engine’s cylinder to produce detonations, further inducing engine knock. This often goes with an improper air-to-fuel ratio as discussed above.
  • Your knock sensor has failed. Most modern cars have a knock sensor installed, which provides information to the engine control unit about issues related to knocking for self-correction. While this may not be audible, it is still related and worth mentioning. If the sensor in the car is faulty, you will get a false alert that there is an issue.

Dell’s Service Center for Your Saab’s Needs

Knocking sounds can be anxiety-inducing because of the range of how severe the issue can be. At Dell’s Service Center, we believe in eliminating this uncertainty by quickly identifying and resolving the issue, all at a reasonable price. Not only are many dealership services often overpriced, but they may hire inexperienced mechanics that only make matters worse. We employ only the highest qualified and experienced mechanics at Dell’s Service Center.

We have been providing affordable and quality service as far back as 1969. The reason that we have thrived for so long in our community is because we believe in treating every customer with the dignity they deserve. We want to make sure that your experience with us is as good as it possibly can be each time you return to us for maintenance and service.


If your Saab or any European car is experiencing any knocking sounds, we are happy to assist you in diagnosing and repairing any problems. We are located at 840 Vanderperren Way in Green Bay, WI, and we proudly service clients in the Manitowoc and Sturgeon Bay communities and surrounding areas.

It is easy to schedule an appointment with Dell’s Service Center. You can come directly inside to speak to a technician or give our staff a phone call to book an appointment. We look forward to establishing a long-lasting working relationship with you to keep your Saab running smoothly over the coming years.

* Saab Car image credit goes to: Roman Stasiuk.

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