If your Volvo check engine light is on and codes P0300, P0301, P0302, P0303, P0304, P0305 are present, there is a good chance that you have a bad spark plug or ignition coil.
Spark plugs are wear components and should be replaced at the recommended interval (see owner's manual). Don't wait for the check engine to come on.
- Volvo shakes, and the check engine light flashes
- Misfire code present when reading Volvo fault codes
- Reduced fuel economy
- Can't pass State emission test
- Rough idle
- Unexplained engine vibration
What you will need
- Spark Plugs for Volvo
- OEM Volvo spark plugs are typically Bosch or NGK.
- Spark plugs should be pre-gapped at 0.028", 0.035", 0.044"
- Ignition Coils for Volvo
- Some Volvo owners prefer to replace all the coils when changing the spark plugs. Please keep in mind coils do not need to be replaced unless they fail.
- Park your Volvo in a safe workplace and allow the engine to cool down for about thirty minutes. Make sure to engage the parking brakes and remove the key.
- Next, pull the hood release under the dashboard and open the hood.
- If your Volvo engine has an engine cover, pull it off by pulling up the plastic cover.
- Turbo models: If necessary, remove the crossbar over the engine and the turbo charge air pipe (boost pipe) held in place with either a T-25, 10mm, or 8mm bolt.
- Remove all T-30 Torx bolts on top of the engine.
- Pull out the cover over the spark plugs.
- Next, remove the cover near the timing chain.
- Remove the 10mm bolts from each ignition coil.
- Disconnect the wires to the ignition coil by pressing then pulling on the connector.
- Lift the coil and remove it from the spark plug.
- Remove the spark plugs using your spark plug removal tool. Turn the ratchet counter-clockwise to remove the spark plug.
- Apply high-temperature anti-seize to the threads of the spark plugs. Install the new spark plugs and torque to 30Nm. Start threading the new spark plugs by hand to not cross-thread the plugs as you install them.
- Install the ignition coils. Use dielectric grease on the inside of the boot before seating them back onto the spark plugs. Make sure that the ignition coil connectors are not switched around. For example, your connector going to cylinder 2 is now moved to cylinder 3. You will end up with multiple cylinder misfire P0300 P0302 and P0303 even if the ignition coils are not switched, but the connectors are. The key is not to switch around the ignition coil connectors.
If your Volvo check engine light is on, clear it with an OBD2 scanner.
Spark Plug Replacement Interval
The typical spark plug change interval for most Volvo vehicles is 60,000 miles. This range can vary based on the spark plug type. See the owner's manual.
Frequently Asked Questions
What is the Volvo spark plug gap?
- The typical Volvo spark gap ranges from 0.008 to 0.043. Check the spec sticker under the hood. Genuine Volvo spark plugs come pre-gapped.
Can't remove Volvo spark plugs
- If the spark plugs are on very tight. You can warm up the engine then try to remove the stuck spark plug. Use gloves and be careful as you may get burned by the hot engine block.
Getting cylinder misfire after changing Volvo spark plugs
- Make sure the connectors to each of the ignition coils are not switched around.
- It is possible that when you installed an ignition coil, it slid to the side of the spark plugs instead of going on top of the spark plug. Remove the ignition coils and make sure they are installed over the spark plugs.