There are several different reasons why a car makes rattling noises when the driver stops. Four of the most common are normally linked to a failing catalytic converter, loose heat shield, low oil pressure, or a failing water pump.
Therefore, a mechanic may need to inspect the vehicle to identify the source on a case-by-case basis.
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Common Causes and Cost of Repairs
Now that you know the most common causes of these types of problems, you need to become familiar with each issue, repairs that need to be done, and the cost of the fix. That said, here are some key things that you should know.
Failing catalytic converters
As mentioned above, if a car has a failing or bad catalytic converter, the driver will begin to hear rattling noises when they are stopped in drive.
Additionally, if you want to confirm that this is the actual source, you may see other symptoms and signs including the following:
- Check engine light comes on
- Decrease in gas mileage
- Decrease in performance
In essence, if all of these signs and symptoms are a part of this type of problem, the catalytic converter will most likely need to be replaced.
Unfortunately, the cost of these repairs, on average, can range from upwards of $1000. So, the cost of fixing this problem can be relatively expensive to repair.
Loose heat shield
In some cases, this rattling noise may be caused by a loose heat shield instead of a bad catalytic converter. This type of problem usually occurs when the heat shield is damaged by rust and/or poor hardware.
In these situations, the rattling sound is produced by the heat shield because has become too loose.
To fix a loose heat shield, the parts will need to be inspected. And, in many cases, the heat shield may need to be replaced with a new one.
The cost of a new installation can range from about $40 or more if it is a DIY installation. On the other hand, if the vehicle owner takes it to a professional mechanic, the average cost may be about $150 for an hour of labor.
Low Oil Pressure
A common sign of low oil pressure is knocking or rattling sounds. Since the engine oil’s function is to lubricate the components of the engine, the oil levels cannot drop too low.
On the other hand, if the oil is too low to circulate at its designated speed, it will cause rattling noises. This is primarily because metal will be rubbing on metal.
To fix this type of problem, you need to address it right away by getting the oil pressure level up. For example, you may want to use a higher-viscosity oil (i.e. switch oil grades from 5W-20 to 10W-30.
Or, you may want to change your oil filter to increase your oil pressure. Either way, if you get an oil change, this can stop the rattling.
The average cost of a basic oil change can range from about $35 to $60 or more.
Bad Water Pump
Similar to the signs of low oil pressure, a bad water pump can cause rattling when the car stops in park. Since the water pump’s function is to circulate the coolant to keep the engine cool, the belt tensioners and the water pump can wear out over time.
And when this happens, the belt tensioners and a bad water pumper can cause rattling noises.
To fix this type of problem, you need a mechanic to assess the damage. Based on their recommendations, you may repair or replace the water pump.
Therefore, the cost can vary based on several factors. For instance, a water pump repair job can range, on average, from about $400 to $800.
Conclusion
There are several reasons why your car makes rattling noises when stopped in drive. Four of the most commonly known include a failing catalytic converter, a loose heat shield, low oil pressure, and a bad or failing water pump.
Each of these can lead to significant damage to the engine and other components of the vehicle if not repaired properly in a timely manner. The cost of these repairs can also vary based on several factors, including the price of the parts and labor.
