2002 Ford Taurus P0302 and P0316 Misfire: Post-Overheat Diagnosis & DIY Solutions

What engine type do you have? Try swapping the coil pack from cylinder #2 to another cylinder — if the misfire follows the coil, it's likely a faulty coil pack. Also perform a compression test before investing in expensive repairs. Good luck and please update us on your progress. Jeff

The engine is a 3.0L V6 OHV (not overhead cam), commonly known as the Vulcan engine — I’ve heard it’s relatively weak. Where is the coil pack located? I’m not familiar with this component.

Does your vehicle have individual spark plug wires or a coil pack mounted directly above each spark plug?

The spark plug has a wire connected to a square box bolted to the front valve cover. There are six mounting points on this box, and additional wires run from it to another location. It resembles an old distributor but lacks a rotor or points — it’s sealed with only wiring connections.

That confirms it's a coil pack setup, not coil-on-plug. I'd recommend starting with a compression test and checking for injector issues — though overheating makes head gasket or cylinder head cracking more likely. Vacuum leaks are also common on Taurus models, especially around the intake manifold gaskets and PCV valve area. A cracked head is a serious concern — experienced mechanics use specialized tools that may not be accessible to DIYers. Good luck and please keep us updated. Jeff

Hi Austin, I’m sure Jeff won’t mind me adding my two cents (or rather, cents — I’ve spent about 40 hours diagnosing the same issue on a 2002 Taurus with the same engine and year, though mine affects cylinder #3 and I never had an overheating event. I agree with Jeff’s assessment — if the engine reached high temperatures enough to melt a spark plug tip, it likely also caused head or head gasket damage. While DIYers can perform basic checks, factory-trained mechanics have tools and techniques that may be beyond typical home access. Only after negative results from compression test, cylinder leakage test, and radiator pressure test should you consider other causes. Many auto parts stores in the U.S. offer free tool loans for diagnostics. First: Perform a compression test. Second: Run a cylinder leakage test. Third: Use a radiator pressure tester — apply 10–12 psi, start the engine and monitor temperature. If coolant pressure rises above cap pressure, it indicates head or gasket failure. Lastly, I have a combustion gas analyzer tool — similar to an oversized tube filled with special fluid. When placed in the cooling system, it draws heat vapors and changes color if combustion gases are present. This test can confirm whether cylinder integrity is compromised. Could melted spark plug material have clogged the injector? Just a thought. I’d also suggest joining the thread between Jeff and me — we may be able to share insights on diagnosing this common Taurus issue before it spreads further. Regards

I'm having the same problem with my 1999 Taurus SE (Vulcan engine). Cylinder #1 has been misfiring since April. The distributor and spark plug wires were replaced, but the issue persists. I found orange-like liquid buildup in the spark plug chamber — it soaked up when tapped on paper. We thought it might be radiator fluid leaking through a gasket or condensation. Could this be due to a combination of poor compression and a leaky head gasket? Or is it just one root cause? I’ll have it checked soon, but any guidance on where to start would help.

I had the same P0306 (cylinder 6 misfire) and P0316 issue on my 2005 Taurus. I didn’t know what P0316 meant initially, but after overheating, I replaced the water pump and engine. After reassembly, the check engine light immediately came back with repeated cylinder 6 misfires. Plugs and wires were replaced — it ran fine for about three days before returning. Eventually, replacing the coil pack and PCV valve triggered P0316 along with P0306. I concluded that my ECU was malfunctioning. It’s surprising how many Taurus owners report similar issues — any help would be appreciated.

But why doesn’t the ECU log misfires before overheating? If it were a failed PCM, it should detect and record misfiring events. I suspect you have a cracked cylinder head or blown head gasket — especially if this was a used engine installation. If so, that used engine needs to be replaced or repaired.