OBD-II Code P0310 — What It Means & How to Fix It

What Does This Error Mean?

P0310 means the PCM detected a misfire in cylinder 10. This code only applies to engines with 10 or more cylinders. A misfire means that cylinder is not burning fuel correctly on some or all of its firing events. You may feel rough idle, power loss, or shaking, especially under acceleration.

Affected Models

All 1996+ vehicles with 10 or more cylinders
Common in Ford F-250/F-350 with the 6.8L V10 engine
Common in Dodge Viper with the 8.4L V10 engine
Common in GM heavy-duty trucks with large V8 engines that share similar circuitry
Common in Lamborghini and other high-performance V10 vehicles

Common Causes

Worn or fouled spark plug on cylinder 10 no longer producing a strong spark
Failed or weak ignition coil on cylinder 10 not delivering enough energy
Clogged or failed fuel injector on cylinder 10 causing a lean misfire
Low compression in cylinder 10 from worn rings, a damaged valve, or a head gasket issue
Damaged spark plug wire or boot on cylinder 10 (on distributor-based ignition systems)

How to Fix It

Use an OBD-II scanner to confirm P0310 and check if any other misfire codes are stored alongside it. A single-cylinder misfire that stays on one cylinder consistently usually points to that cylinder's ignition or fuel system components.

Multiple misfire codes across several cylinders often indicate a different root cause such as a vacuum leak, low fuel pressure, or a failing coil pack.
Inspect the spark plug on cylinder 10. Remove it and look at the electrode. Black sooty deposits suggest a rich condition. White or gray deposits indicate lean running or heat issues. A worn, cracked, or fouled plug should be replaced.

Always replace plugs in sets on high-mileage engines. A new plug in one cylinder with 100,000-mile plugs in the rest is only a temporary fix.
Swap the ignition coil from cylinder 10 with a coil from a non-misfiring cylinder. Clear the codes and drive. If the misfire code moves to the new cylinder (the one that received cylinder 10's coil), the coil is defective.

Coil swapping is the quickest way to confirm a bad coil without expensive testing equipment. Only swap identical coils.
Check the fuel injector on cylinder 10. If the misfire stays on cylinder 10 after swapping the coil, swap the injector next. A clogged or failed injector causes a lean misfire that no spark plug or coil can fix.

A lean misfire is often worse under light throttle and may improve under heavy acceleration when more fuel is commanded.
Perform a compression test on cylinder 10 if ignition and fuel components check out. A healthy cylinder should read within 15% of the other cylinders. Low compression points to a mechanical issue requiring more in-depth engine inspection.

A leakdown test after a compression test can tell you exactly where compression is escaping — past rings, valves, or a head gasket.

When to Call a Professional

If new spark plugs and a coil swap do not solve the misfire, the issue may be mechanical. Low compression in cylinder 10 requires a compression test and possibly an engine teardown. A shop can perform a cylinder-specific compression and leak-down test. Diagnosis typically costs $100-$150. Ignition parts are inexpensive; compression repairs can cost $1,000 or more.

Frequently Asked Questions

What cars have a cylinder 10?

P0310 only applies to engines with 10 or more cylinders. The most common are the Ford 6.8L V10 found in Super Duty trucks. The Dodge Viper V10 and some European performance cars also apply. If your vehicle has a V8 or smaller engine, P0310 should not appear.

Can I drive with a cylinder 10 misfire?

Short drives are possible but not recommended. A persistent misfire sends raw fuel into the exhaust. This can overheat and damage the catalytic converter quickly. On a large V10 truck, fuel economy also drops noticeably with a misfiring cylinder.

Why does my misfire only happen when the engine is cold?

Cold misfires often point to a spark plug, coil, or injector that works marginally. Cold conditions demand more from ignition components. A weak coil or partly clogged injector may work once warm but fail when cold. P0316 is a related code specifically for startup misfires.