Check Engine Light & Engine Diagnostics in Carmel, IN

A check engine light means the engine computer has stored a fault code. The cause could be a loose gas cap, or it could be a misfire that's slowly damaging your catalytic converter.

Our ASE-certified technicians diagnose check engine lights, drivability and engine performance problems on all makes and models, and look for the actual cause instead of just clearing the code.

Book Online or call (317) 626-5312

ASE-certified technicians · All makes and models · Mon–Fri 8 AM–5 PM · After-hours drop-off

Evolution Motorwerks technician working under the hood of a car at the Carmel, IN shop

Engine problems we diagnose

Check engine light, solid or flashing
Misfires, rough idle or shaking at a stop
Hesitation, stalling or poor acceleration
A drop in fuel economy with no obvious cause
Hard starting, or an engine that cranks but won't fire
Emissions-related faults such as oxygen sensors, EVAP leaks and catalytic converter codes
Rattling or chain noise at startup, which can point to timing chain wear

How engine diagnostics work

Read the codes and freeze-frame data

A fault code like P0301 or P0420 points to a system, not a part. Freeze-frame data shows the conditions when the fault set, such as speed, temperature and load.

Confirm the symptom

Whenever possible, we reproduce the problem so we know exactly what we're fixing.

Test before replacing parts

One code can have several causes. A misfire, for example, can come from a coil, a plug, an injector or a mechanical problem. Testing narrows it down before parts get replaced.

Explain and repair

We tell you what we found and what it takes to fix it, from a simple sensor up to heavy-line engine work like timing chains or an engine replacement.

Solid vs. flashing check engine light

A solid light means a fault has been stored. The car is usually safe to drive for a short time, but have it checked soon, because small faults can turn into expensive ones.

A flashing light usually means an active misfire. Unburned fuel can overheat and ruin the catalytic converter, so ease off, avoid hard acceleration and get the car checked as soon as you can. If the engine is running badly or overheating, stop driving and call us at 317-626-5312.

Why a free code read isn't a diagnosis

A parts-store scan gives you a code, and that's a useful starting point. But a code like "system too lean" can come from a vacuum leak, a weak fuel pump, a dirty sensor or an exhaust leak. Replacing parts based on the code alone can get expensive. Proper diagnosis means testing the system the code points to.

Engine trouble sometimes shows up as a transmission or electrical problem, and the other way around. See also battery, starting and charging and transmission service.

Check Engine & Diagnostics FAQ

Is it safe to drive with the check engine light on?

If the light is solid and the car drives normally, it's usually safe for a short time, but have it checked soon. If the light is flashing, the engine is likely misfiring, which can damage the catalytic converter. Drive gently and get it checked right away, or stop driving if the engine runs badly or overheats.

Can a loose gas cap turn on the check engine light?

Yes. A loose or worn gas cap can set an evaporative emissions (EVAP) leak code. Tighten the cap until it clicks. The light may take several drive cycles to turn off. If it stays on, have the system checked.

Why is my check engine light flashing?

A flashing check engine light usually means an active engine misfire. Common causes include worn spark plugs, a failing ignition coil or a fuel injector problem. Because a misfire can overheat the catalytic converter, it should be diagnosed as soon as possible.

Will the check engine light go off on its own?

Sometimes. If the fault was temporary, the light can turn off after several drive cycles, but the code stays stored in memory. A recurring light is worth diagnosing before a minor fault becomes a major repair.

Do you handle major engine repairs like timing chains and engine replacements?

Yes. Along with diagnostics, we handle heavy-line engine work, including timing chains and engine replacements, on all makes and models.

Browse all auto repair services, return to the Evolution Motorwerks home page, or contact us with a question.

Get your check engine light diagnosed

When you book, let us know whether the light is solid or flashing and what the car is doing.