P0300 on Volvo
Random/Multiple Cylinder Misfire Detected
P0300 on Volvo vehicles indicates random/multiple cylinder misfire detected. Au7o has documented this code across 3 Volvo models — most commonly on 850, C30, V90. P0300 means the engine computer detected misfires occurring randomly or across multiple cylinders rather than in one specific cylinder. A misfire is when a cylinder fails to ignite its fuel-air mixture properly, which the computer senses through small fluctuations in crankshaft speed. Because it's not isolated to one cylinder, the cause is usually something that affects the whole engine — like fuel, air, or ignition system problems — rather than a single coil or plug. Persistent or heavy misfiring wastes fuel, runs rough, and can damage the catalytic converter, which is why a flashing check engine light should be taken seriously. Typical repair costs on Volvo range from $50 to $500, depending on the specific model and root cause.
Common Causes of P0300
- •Worn or fouled spark plugs (across cylinders)
- •Vacuum or intake air leak
- •Weak fuel pump, clogged fuel filter, or low fuel pressure
- •Failing ignition coils or worn spark plug wires
- •Dirty or faulty mass airflow (MAF) sensor
- •Clogged or dirty fuel injectors
- •Faulty crankshaft/camshaft position sensor
- •Low compression or EGR/PCV system faults
P0300 on Volvo by Model
Volvo 850(1 issue)
- Distributor Cap and Rotor Failure1993-1997
The distributor cap and rotor on the 850 5-cylinder develop carbon tracking and contact wear, causing misfires and hard starting. The distributor seal also leaks oil into the cap.
Volvo C30(1 issue)
- Rough Idle and Engine Hesitation2008-2013
Nearly 20% of C30 owners report rough idle issues according to Consumer Reports data. The rough idle can be caused by several factors: failing ignition coils, ETM (Electronic Throttle Module) issues, PCV system failures, and vacuum leaks. The 2.5L turbo I5 is particularly sensitive to PCV system degradation which causes positive crankcase pressure and oil ingestion into the intake. The 2.0L I4 models are less affected but can develop similar idle issues from ignition coil failures.
Volvo V90(1 issue)
- T6 Supercharger Intercooler Condensation and Hesitation2017-2021
The T6 compound-charged (turbo + supercharger) engine can accumulate condensation in the intercooler, causing a stumble or misfire on initial acceleration, especially in humid conditions. The charge air cooler design traps moisture at the bottom.
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View P0300 across all makes →Frequently Asked Questions
What does P0300 mean on Volvo?▼
P0300 stands for "Random/Multiple Cylinder Misfire Detected." P0300 means the engine computer detected misfires occurring randomly or across multiple cylinders rather than in one specific cylinder. A misfire is when a cylinder fails to ignite its fuel-air mixture properly, which the computer senses through small fluctuations in crankshaft speed. Because it's not isolated to one cylinder, the cause is usually something that affects the whole engine — like fuel, air, or ignition system problems — rather than a single coil or plug. Persistent or heavy misfiring wastes fuel, runs rough, and can damage the catalytic converter, which is why a flashing check engine light should be taken seriously. On Volvo specifically, this code is documented across 3 models.
What causes P0300 on Volvo vehicles?▼
Common causes on Volvo: Worn or fouled spark plugs (across cylinders), Vacuum or intake air leak, Weak fuel pump, clogged fuel filter, or low fuel pressure, Failing ignition coils or worn spark plug wires, Dirty or faulty mass airflow (MAF) sensor. Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0300 on a Volvo?▼
Repair costs on Volvo range from $50 to $500, depending on the specific model and root cause.
Which Volvo models have P0300 documented?▼
Au7o has documented P0300 on 3 Volvo models: 850, C30, V90.