2015 Volvo S80 Has Rough Idle

Diagnosing Causes of Rough Idle in Your 2015 Volvo S80 and Solutions for a Smoother Ride

Find Repair Location
Reviewed by
Devin Cabugcal
Written by RepairPal Car Genius
Updated January 14, 2025
0%
21% chance it's the
Spark Plugs
0%
15% chance it's the
Ignition Coil
0%
64% chance it's
Something else
The most common reasons a 2015 Volvo S80 has rough idle are a vacuum leak, an issue with the spark plugs, or a problem with the ignition coil.
  • Spark Plugs: Worn or fouled spark plugs can lead to misfires, poor fuel economy, and difficulty starting the engine.
  • Ignition Coil: A faulty ignition coil can cause misfires, rough idling, and difficulty starting the engine due to inadequate spark delivery to the spark plugs.
Proper diagnosis will determine the exact cause of your symptom, saving you money on unnecessary repairs. The diagnostic experts at RepairPal Certified shops have the right tools and experience to solve any symptom.

How much does it cost to fix a 2015 Volvo S80 has rough idle?

Common Repairs

The total repair cost will vary based on the condition of your vehicle and the number of repairs needed to fix your symptom. Proper diagnosis will save you money by finding the exact repairs needed to fix your car right the first time.

Here are a few common symptoms of worn-out brake pads:

  1. Low brake pad warning light is on: Not all vehicles are equipped with this system, but if yours is, this dashboard indicator light will likely be the first signal it’s time to replace your brake pads.
  2. Brakes start to squeal regularly: This is often one of the first signs of worn brake pads and is caused by a metallic piece built into brake pads for this exact purpose. This part contacts the brake rotor to make a squealing or whining noise when the pads are low.
  3. Brakes make loud grinding noise: If not addressed early enough, your brake pads may get so worn that the metal backing plate of the pad grinds against the metal rotor.
  4. Brake pads look thin: You may be able to visually check your brake pad thickness to determine if they need replacement.

Most often, a brake system inspection will just be a routine portion of manufacturer specified maintenance, and will be performed at mileage intervals. In those cases, there will likely be no symptoms. However, when a brake system makes a funny noise, causes vibration, is hard to use, will not slow the vehicle, prevents the vehicle from driving, makes the vehicle pull to one side, or leaks brake fluid, the vehicle will need a visit dedicated to the inspection of the brake system.

What are the steps to diagnose a rough idle in a 2015 Volvo S80?

To effectively diagnose a rough idle in your 2015 Volvo S80, start with a systematic approach that prioritizes simpler checks before delving into more complex diagnostics. Begin by inspecting the coolant temperature sensor, as a malfunction here can significantly impact engine performance. Next, examine the spark plugs for wear and tear, since old plugs can lead to poor combustion and rough idling. Following this, assess the Idle Air Control System, which plays a crucial role in maintaining a stable idle; any issues here should be addressed promptly. Additionally, check the Mass Airflow Sensor (MAF) for any signs of damage or dirt, as this component is vital for accurate air intake measurement. Lastly, do not overlook the possibility of vacuum leaks, which can disrupt the air-fuel mixture and cause instability in idle. By methodically addressing these areas, you can effectively identify and resolve the underlying causes of a rough idle in your vehicle.

What are the common problems that could cause a rough idle in a 2015 Volvo S80?

When dealing with a rough idle in a 2015 Volvo S80, it's essential to understand the common problems that may be at play. One of the primary culprits is a faulty Throttle Position Sensor (TPS), which can cause erratic fluctuations in engine speed, making the idle feel unstable. Another potential issue is a malfunctioning crankshaft position sensor, which can lead to irregular RPMs and vibrations during idle. Additionally, a defective coolant temperature sensor may send incorrect data to the Engine Control Unit (ECU), resulting in rough idling and even stalling. The idle control valve is also a critical component; if it fails, it can cause significant variations in idle speed. Lastly, don't overlook the instrument cluster, as issues like a faulty fuse or error codes can contribute to the rough idle experience. By identifying and addressing these common problems, DIYers can restore their Volvo S80's performance and ensure a smoother driving experience.

How urgent is it to address the rough idle in my 2015 Volvo S80?

Addressing a rough idle in your 2015 Volvo S80 is not just a matter of comfort; it is crucial for the overall health of your vehicle. Ignoring this symptom can lead to a cascade of issues, including decreased fuel efficiency and potential damage to engine components, which could escalate into more serious problems. A rough idle often indicates underlying issues that, if left unchecked, may compromise your vehicle's performance and safety. For DIY enthusiasts, it is essential to recognize that timely intervention can prevent costly repairs down the line. Regular maintenance and prompt attention to symptoms like a rough idle can enhance the reliability of your Volvo S80, ensuring it runs smoothly for years to come. Therefore, if you notice your vehicle idling roughly, it is advisable to investigate the cause and address it as soon as possible to maintain optimal performance and safety.

You’ve got options with RepairPal

Whether you need a more accurate auto repair estimate or help finding a reputable shop in your area, we’ve got you covered.