24/7 mobile service · Riverside
Engine shaking or misfiring? Start with the plugs and coils.
Worn spark plugs and failing ignition coils are among the most common causes of a misfire. We find the cylinder at fault and replace the plugs and coils at your location.
Sounds like this?
Signs it's time to call
- Engine shakes or stumbles at idle
- Hesitation when you accelerate
- Check engine light, especially if it flashes
- Worse fuel economy than usual
- Plugs are past the interval in your manual
What we measure
P0301–P0306- Misfire on a specific cylinder, which tells us where to look
Coil swap test- Moving a coil to another cylinder shows whether the misfire follows it
Plug condition- Worn, oily, or carbon-fouled plugs tell us about engine health
Interval- Many modern iridium plugs last around 100,000 miles. Check your manual
From our jobs
The visit
What happens when we arrive
- Scan for misfire codes and watch misfire counts live
- Swap-test coils to confirm the failed part
- Replace the plugs, gapped and torqued to spec
- Replace failed coils and inspect boots and connectors
- Clear codes after the repair and road-test
When it's a shop job
On some V6 engines the rear plugs sit under the intake plenum, which adds time. If a misfire comes from low compression or a fuel injector, we'll tell you what we found and quote that separately.
Questions people ask
Should I replace all the coils or just one?
Usually just the failed one. If the coils are original and high-mileage, we'll give you both prices so you can choose.
Can I drive with a misfire?
A flashing check engine light means stop driving soon. A severe misfire can overheat and damage the catalytic converter.
Do new plugs improve fuel economy?
If the old plugs were worn enough to misfire, yes. If they were in good shape, you won't notice much.