Common Car Problems and What Usually Fixes Them

A pull after new tires is usually alignment, uneven tire pressure or, less often, a tire with an internal pull. Old tires can hide an alignment problem because they have already worn to match it. New tires show it right away.

What we inspect: pressures, tire swap test, alignment readings, and worn steering or suspension parts. Need versus want: a strong pull is a need. A slight drift on a crowned road may be normal. See alignment after new tires.

A shake that starts around 60 to 70 mph and smooths out at other speeds usually points to wheel balance. Other causes include a bent wheel, a tire with a flat spot or a belt shift, and worn suspension or axle parts.

What we inspect: wheel balance, tire condition, wheel runout, and front end parts. Need versus want: a new shake after hitting a pothole is a need. Road force balancing is often a want unless standard balancing did not fix it. See road force balancing.

A high squeal often comes from a wear indicator telling you the pads are getting low. A grind usually means metal on metal, which damages rotors quickly. Some squeal comes from dust or hardware and does not mean the pads are worn.

What we inspect: pad thickness, rotor condition, hardware, and brake fluid. Need versus want: grinding is a need. A light squeal with good pad thickness can wait. We photograph the pads so you can see.

A soft or sinking pedal can mean air in the lines, old moisture-filled fluid, a leak, or a failing master cylinder. It is a safety problem because stopping distance can grow without much warning.

What we inspect: fluid level and condition, leaks at each wheel and line, and pedal behavior on a road test. Need versus want: always a need. If the pedal sinks to the floor, do not drive the car. Call (909) 608-7699.

Warm air usually means low refrigerant from a leak, a compressor that is not engaging, an electrical fault, or a blend door problem. Weak airflow that is still cold often points to a clogged cabin filter or a blower issue.

What we inspect: vent temperature, pressures, leak check, compressor operation and airflow. Need versus want: in summer heat, fixing a warm AC is close to a need, especially for kids and older passengers. A recharge without finding the leak is a want that rarely lasts. See air conditioning service.

A slow crank usually means a weak battery, corroded terminals or a charging problem. A new battery that dies again may point to the alternator or a parasitic drain. A check engine light that returns after being cleared means the root cause was never fixed.

What we inspect: battery load test, charging output, starter draw, stored codes and freeze frame data. Need versus want: a failing battery test is a need. See check engine light diagnostics.

The wear pattern tells a story. Center wear points to overinflation. Both edges wearing points to underinflation. Inner edge wear usually means alignment. Cupping often means worn shocks plus skipped rotations. Feathering often points to toe.

What we inspect: tread depth across each tire, alignment readings and suspension parts. Need versus want: tread near the limit is a need. Correcting alignment early is a smart want that saves the next set. See tire wear patterns.

Smells and puddles are early clues that often show up before a warning light. A sweet smell usually means coolant, a sharp burning smell can be oil on a hot exhaust, and a rotten egg odor often points to the exhaust or catalytic converter. The color of a drip narrows it further.

What we inspect: leak points, fluid levels and the exhaust. Need versus want: brake fluid or active coolant leaks are needs.

A clunk over bumps often comes from worn sway bar links, bushings or ball joints. A rhythmic click during tight turns usually points to a worn CV joint. Some knocks come from loose items in the trunk, so empty it before booking. Worn steering and suspension parts affect control and tire wear.

What we inspect: ball joints, tie rods, control arm bushings, sway bar links, CV boots and shock mounts, with the car lifted. Need versus want: play in a ball joint or tie rod is a need. A torn CV boot that has not yet made noise is a near-term need, since dirt gets in quickly.

A few quick checks either solve the problem or give the technician a head start. Look at tire pressures, glance under the car for fresh spots after it sits overnight, and note whether the symptom changes with speed, braking or turning. Stop there if the problem involves brakes or steering.

• Pull or drift: set all tire pressures to the door sticker, then test again.
• Weak AC airflow: check whether the cabin filter is packed with debris.
• Slow start: look for white or green crust on the battery terminals.
• Repeat check engine light: check that the gas cap clicks shut.
• Shake: note the speed where it starts and whether braking changes it.