It’s time for a car checkup when you notice a warning light, brakes that feel or sound different, new noises, vibration or pulling, loss of power, hard starting, worse gas mileage, fluid leaks, or smoke and strange smells. Some of these can wait a week or two. A flashing check engine light, a red warning light, a sinking brake pedal, or smoke means stop driving.
Quick answer
- Stop driving: flashing check engine light, red oil or temperature light, a soft or sinking brake pedal, smoke or steam.
- Within a few days: grinding brakes, a steady check engine light, clunks, pulling, hard starting.
- Soon: small leaks, slowly dropping gas mileage, mild vibration at highway speed.
- Each sign points to a specific system, so tell the mechanic exactly when it happens.
How urgent is each warning sign?
We sort warning signs into three levels. Stop driving means pull over when it’s safe and call for help, because driving on can cause major damage or put you at risk. Within a few days means the car is usually drivable for now, but the problem can get worse or more expensive to fix. Soon means book a visit in the next week or two. When in doubt, call and describe what’s happening.
Warning lights and brake changes
1. The check engine light is on or flashing
What it usually means: the engine computer found a fault. It can be something small like a loose gas cap, or a failing sensor, a misfire, or a catalytic converter problem.
How urgent: a steady light means within a few days. A flashing light means an active misfire that can overheat the catalytic converter, so stop driving. See our check engine light service.
2. Other dashboard warning lights
What it usually means: red lights such as oil pressure, engine temperature, or the BRAKE light point to problems that can quickly damage the engine or affect stopping. Yellow lights like ABS or tire pressure are less urgent. A tire pressure light often means one tire is low or a sensor has failed.
How urgent: red lights mean stop driving. Yellow lights mean within a few days. We handle tire pressure sensors and ABS problems.
3. Brakes squeal, grind, or feel soft
What it usually means: a steady squeal is often the pad wear indicator. Grinding usually means metal on metal. A soft or sinking pedal points to a fluid leak, air in the lines, or a master cylinder problem.
How urgent: a soft or sinking pedal means stop driving. Grinding means within a few days. See brake repair.
Noises, vibration, and pulling
4. New clunks, clicks, or rumbles
What it usually means: a clunk over bumps often points to worn suspension parts like sway bar links, ball joints, or struts. A clicking sound when turning is a classic sign of a worn CV axle. A loud rumble from under the car often means an exhaust leak.
How urgent: within a few days. Related services: steering and suspension, CV axle repair, and exhaust and muffler repair.
5. Vibration or pulling to one side
What it usually means: vibration at highway speed is often an out-of-balance tire. Pulling can come from uneven tire pressure, alignment, or worn steering parts. Vibration only when you brake usually points to the rotors.
How urgent: soon for mild vibration. Within a few days for strong pulling or shaking. Start with steering and suspension.
Power, starting, and fuel economy
6. Loss of power or hesitation
What it usually means: misfires from worn spark plugs or coils, a clogged fuel filter, a weak fuel pump, or a sensor giving bad readings.
How urgent: within a few days. Stop driving if it can’t keep up with traffic safely. See fuel pump replacement.
7. Hard starting
What it usually means: a slow crank usually means a weak battery or corroded cables. A single click can be the battery or the starter. If the engine cranks normally but won’t start, the problem is more likely fuel or ignition.
How urgent: within a few days, before it leaves you stranded. See battery, alternator, and starter service.
8. Worse gas mileage
What it usually means: low tire pressure, a dirty air filter, worn spark plugs, a lazy oxygen sensor, or a brake that’s dragging.
How urgent: soon. A tune-up often brings mileage back.
Leaks, smoke, and strange smells
9. Fluid under the car
What it usually means: brown or black and slick is usually engine oil. Green, orange, or pink with a sweet smell is coolant. Clear to amber and slippery near a wheel may be brake fluid. Clear water under the front on a hot day is normal A/C condensation.
How urgent: brake fluid means stop driving. Coolant means within a few days. A small oil drip means soon. See cooling system repair and engine repair.
10. Smoke, steam, or strange smells
What it usually means: steam and a sweet smell mean coolant, often from an overheating engine. Burning oil smells like hot cooking oil. A rotten egg smell often points to the catalytic converter. A musty smell from the vents usually comes from the A/C system.
How urgent: smoke, steam, or exhaust smell inside the cabin means stop driving. Exhaust inside the car can contain carbon monoxide. A musty vent smell can wait. See auto A/C repair.
What should you tell the mechanic?
The more specific you are, the faster the problem gets found. Before you come in, try to note:
- When it happens: cold or warm engine, at what speed, and while braking, turning, or accelerating
- Where the noise or smell seems to come from
- Whether a warning light came on and if it stayed on
- A short phone video of the noise, if you can record it safely
Don’t clear warning lights before the visit. The stored codes help pinpoint the cause. You can see everything we work on on our services page.
Something feels off but you’re not sure what?
Our ASE-certified mechanics scan the car, check the system behind the symptom, and explain what’s urgent and what can wait, in English or Spanish.
Car checkup FAQ
How often should a car get a checkup?
Follow the maintenance schedule in your owner’s manual, and have a mechanic look over the brakes, tires, and fluids at each oil change. Any of the signs above is a reason to come in sooner.
Is it safe to drive with the check engine light on?
If the light is steady and the car drives normally, it’s usually OK to drive to a shop soon. If the light is flashing, stop driving, because an active misfire can damage the catalytic converter.
What does a car checkup include?
A good checkup usually covers brakes, tires, fluids, belts and hoses, the battery, lights, and suspension, plus a computer scan if a warning light is on.
Can I bring my car in without an appointment?
Yes. Walk-ins are welcome, and calling ahead at (301) 762-1200 gets you in faster. We also have a night drop.
Do you work on all makes and models?
Yes. Our ASE-certified mechanics work on all makes and models, and we speak English and Spanish.
Bring your car to New Level Auto Service
We’re at 716 E Gude Dr in Rockville, MD. Walk-ins are welcome, and calling ahead gets you in faster.
- Phone (301) 762-1200
- Hours Monday to Friday 8 AM to 5 PM, Saturday 9 AM to 2 PM
- Extras Night drop and 24-hour emergency towing