Should you replace your car’s serpentine belt when you replace the alternator? – Jalopnik

The short answer here is: yes, in most cases you will need to replace your car’s serpentine belt when you replace the alternator. The problem is not so much that the two components are part of the same system, even if they are. There is a well-known key principle at work here.

Consider a situation where you need to replace a worn or broken part, but the only way to access that part is to remove another part that is still functioning. Often it makes sense to go ahead and replace the first part since you’ve already gone through the trouble of removing it. That’s exactly what happens under the hood of most internal combustion cars, essentially requiring you to remove the serpentine belt to remove the alternator.

There are of course exceptions. The basic job of an alternator and serpentine belt is to convert the engine’s mechanical power into electricity, which is then used to run the vehicle’s electrical systems and keep the battery charged. So-called mild hybrids rely on a different setup, with an integrated starter generator, to do the same thing. While you won’t have to worry about an alternator blowing or a belt breaking with a mild hybrid, they can be a lot more expensive to repair. Just replacing a new mild-hybrid battery can cost $1,500 or more.

The only electricity an internal combustion engine really needs is the spark from the spark plugs. They can even be started by hand, which is back when people had to crank them to get them moving – the electric starter only first appeared with the 1912 Cadillac Model 30, which was also the first car with electric headlights. When cars started adding electrical accessories, automakers developed generator systems to meet their needs, but these were usually unreliable, inefficient, and not very good at generating electricity at low engine speeds.

That all changed with Chrysler’s 1960 Valiant. It was the first car with a modern alternator as standard equipment – ​​and also the first car with the Slant 6 engine, a strangely tilted engine that refused to die. As for the alternator, it consisted of two main parts: a rotor that is essentially shaped like a donut and rotated by engine power, and a stator that is wrapped in wire and remains stationary in the center of the donut. As the donut spins, the magic of electromagnetism creates electricity, which is then used to power the car’s accessories and help keep the battery topped up.

What causes the alternator rotor to turn instantly in the first place? That would be the serpentine belt, which is driven by a pulley connected to the crankshaft. The belt then wraps around a number of other pulleys to provide power not only to the alternator, but also to things like the power steering, the air conditioning compressor, and the water pump.

Let’s take a look: A serpentine belt plays a huge role while driving, not only by providing comfort features like the air conditioning, but also by running the water pump to keep your engine from overheating. If that happens, you could be faced with permanent engine damage. It is also not safe to drive if your power steering – also powered by the serpentine belt – suddenly fails. At that point you’re trying to wrestle with thousands of pounds of metal – no easy task.

But all that and more depends on a piece of reinforced rubber that can cost less than $10 and usually lasts only 60,000 to 100,000 miles. Considering that today’s average car can last up to 200,000 miles, and some have exceeded the seven-figure mark, simple wear and tear will likely result in at least one serpentine belt replacement during a vehicle’s lifespan.

You can spot the signs of that wear and tear by listening for squealing/squealing noises coming from the engine compartment. (But remember, there’s a long list of terrible things you should never use to silence a noisy engine belt.) Additionally, you should be alert to signs of inconsistent electricity production from the alternator, such as flickering lights when you first start your car. Don’t forget routine visual inspections to check the belt for cracks, fraying rubber, worn edges, worn grooves on the underside of the belt, and a shiny appearance on the top.