How to tell if the starter is bad

Starter or battery

The jump start row settles most arguments. If a good jump from a running car changes nothing, the problem is past the battery.

What a starter does and how it fails

The starter is an electric motor with a small gear on the end. Turn the key and a solenoid does two things at once: it shoves that gear forward into the teeth on the flywheel, and it closes a heavy contact that feeds the motor several hundred amps of current. The motor spins the engine over until it fires, then the gear retracts.

It is a brutal job done briefly, a few times a day, for ten or fifteen years. Things wear.

The brushes are carbon blocks that carry current to the spinning armature. They wear down, and when they get short they make intermittent contact. That is the source of the single most confusing symptom in this whole area: a car that starts perfectly four times and refuses the fifth.

The solenoid contacts pit and burn from the current passing through them. That gives you a click with no crank.

The bendix, which is the mechanism that pushes the gear forward, can stick or its one-way clutch can slip. That gives you a high pitched whirr with no engine movement, because the motor is spinning happily and not turning anything.

And the bearings seize, usually after making noise for a while first.

The dash light test, which takes ten seconds

This is the fastest way to separate the two suspects and it needs nothing but your eyes.

Turn the headlights on. Now turn the key to start and watch the dashboard and the headlights at the moment you do it.

If the lights stay bright and steady while the car refuses to crank, there is plenty of voltage in the system. The battery is doing its job. The fault is downstream: the starter, the heavy cable feeding it, or the ignition switch circuit that tells it to go.

If the lights dim dramatically or die altogether, voltage is collapsing under load. Either the battery cannot deliver the current or a corroded connection is choking it before it gets there. That is a battery and cables problem, not a starter problem.

Combine that with the sound. Bright lights plus one solid click is close to a diagnosis on its own.

The sounds and what each one means

One loud clunk and nothing. The solenoid engaged and the motor did not turn. Worn brushes, a dead armature segment, or burnt solenoid contacts.

Rapid clicking. The solenoid is pulling in and dropping out repeatedly because voltage collapses each time the motor tries to draw current. Battery or connection, not starter.

Grinding, like gears crunching. The starter gear and the flywheel teeth are not meshing cleanly. This one needs attention quickly, because it chews teeth off the flywheel, and a flywheel is a much larger job than a starter.

A high pitched whirr or whine with no engine movement. The motor is spinning but the gear is not engaging. That is the bendix.

Complete silence with bright lights. Could be the starter, and could equally be the ignition switch, the starter relay, the neutral safety switch or the clutch switch. This is the one symptom on the list that genuinely needs a meter rather than an ear.

A grinding that continues after the engine fires. The gear is not retracting. Shut the engine off and stop starting it.

Four cheaper things that imitate a bad starter

Before anyone quotes you a starter, these deserve ruling out, because all four are less expensive and two of them are free.

Battery terminals and the main cables. Corrosion adds resistance, and resistance in a circuit carrying several hundred amps produces a dead-feeling car with a healthy battery. Look for white or green crust, and try twisting each clamp by hand.

The neutral safety switch, or transmission range sensor. It tells the car it is safe to crank. When it drifts out of adjustment the car refuses in Park and starts perfectly in Neutral. Try Neutral before you try anything else. On a manual, push the clutch all the way down, because the clutch switch has to close.

The starter relay. A five dollar part that can fail in a way that looks exactly like a dead starter. On many cars you can swap it with an identical relay from elsewhere in the fusebox as a test.

The ignition switch itself. Worn contacts stop the start signal ever reaching the relay. The tell is usually other electrical oddities at the same time, like accessories cutting out when you turn the key to start.

Why the intermittent version is the one to act on

A starter that has failed completely is annoying and honest. A starter that works most of the time is the one that costs people money.

Worn brushes fail by position. When the motor stops with the worn brushes over a gap in the commutator, there is no contact and nothing happens. Turn the key again, the armature has usually moved slightly, and it starts fine. So the car appears to have an occasional mysterious fault rather than a wearing part.

That pattern almost always gets worse on a curve rather than a straight line. It goes from once a month to once a week to twice a day over a couple of months. And because it works most of the time, it very reliably fails on the coldest morning, in the rain, when you are already late, because cold thickens the oil and asks the starter for more current than it has left.

If your car has clicked once and then started on the second try more than a couple of times, that is worth testing now while it is a scheduling matter.

What we do at the car, and what it costs

We come to the car and measure the starting circuit end to end rather than swapping parts to see what helps.

Load test on the battery first, because a weak battery makes every other reading meaningless. Then voltage drop across each connection in the heavy circuit, both the feed and the ground path, which is the test that finds a corroded cable pretending to be a dead starter. Then voltage at the starter itself with the key turned. Full voltage arriving with no motor movement is a starter, without ambiguity. And a check of the relay, the range sensor and the ignition switch circuit.

If it is the starter, we replace it at the car. Labor starts at $150, and the starter itself is quoted by make and model, because on some cars it sits on top of the engine and on others it comes out from underneath after most of an intake assembly is removed. Those are very different jobs and we would rather tell you which one yours is up front.

If it turns out to be a terminal, a relay or a range sensor, that is what we will tell you, and the bill is a good deal smaller.

Mobile starter replacement across NYC

A car that will not crank is not driving to a shop, so we bring the shop to it. Driveways, street parking, garages and work lots across Flushing and the rest of Queens, Brooklyn, Manhattan, the Bronx, Staten Island and Long Island.

Text us the year and make, what you hear when you turn the key, and whether the dash lights hold steady. We usually reply in under five minutes, and we can often come the same day.

Common questions