How long do coil packs last?

The combustion process in our cars is highly reliant on burning to combust the fuel in the chambers. The spark plugs are known to be pretty weak as a power source compared to the ignition power required to run the various engines on our roads.

So, how do they do it? Well, they have a little component called the coil pack which works as a magnifier for the battery voltage before it hits the plugs.

Without these rarely talked about coils, the battery alone would not be able to deliver power strong enough to start an engine.

With the coil pack explained, there is another glaring question:

How long do coil packs last?

Off the bat, we’d say ignition coils can go as far as 120,000 miles that are around 5 years before you have to get new ones.

This is called the expected lifespan because most of them don’t make it that far. They deteriorate due to adverse working environments and poor servicing. Some of the most common threats to coil packs are heat, friction, and carbon build-up.

What Are The Symptoms Of A Bad Coil Pack?

There are several direct signs you can look for when you suspect a fault in your ignition coil pack.

The Check Engine Light

This is the first and most common symptom of faulty ignition coils. Modern cars are built with the required technology to detect almost every fault in the system the minute it surfaces.

Whenever your car or truck lights up the check engine light and shows error codes like P0351 then you need to check the ignition coils before they fail on you in the middle of nowhere.

Some cars will register an engine misfire code but the underlying issue is usually bad ignition coils.

Engine Misfires

The ignition coil pack is directly involved in combustion-if it fails or negates in effect then your car will definitely have combustion-related issues like misfiring.

Misfires can be described as jerking behavior in the car even when at relatively stable speeds. When you stop, the engine suddenly runs rough and might even vibrate.

If your car suddenly misfires for no apparent reason then you might want to check out the ignition coils.

Hard Starts

Every time you start your car, the ignition power runs from the battery to maybe the alternator and coil pack and finally to the spark plugs which affect the initial combustion.

If any of these stages is not working then you can expect hard starts-if the engine starts at all. One of the most affected areas is of course the coil pack because of its exposure to heat and other harmful conditions.

 Any car with a coil pack is susceptible to this failure but we must say, cars with single ignition coils are the most affected.

Altered Fuel Economy

Not all car components fail at once, some fail in slow stages until they finally die. One of these parts is the ignition coil-you could be driving your car normally for months without noticing any issues only to later realize that your coils have been misbehaving for months.

The most recommended way to stay ahead of such surprises is to watch your car’s gas mileage. A sudden shift in gas mileage might not point at the ignition coils directly but they are a sure sign that not everything is alright.

Power loss

As mentioned, cars with weak or failing ignition coils are likely to exhibit rough idle signs. This is when your car shakes or vibrates strongly for no reason. To get a clearer diagnosis, you can look for supporting signs like weak acceleration.

The ignition coils are directly involved in combustion which is the car’s primary source of power. If your car feels weak and has trouble accelerating then your ignition coils might be dyeing. If things get worse, stalls will join your list of problems.


Backfiring is when a particle of raw fuel escapes through the exhaust pipe. It is characterized by deafening bangs around the exhaust area.

A lot of car problems can result in backfires with failed ignition coils being one of the most common. Some drivers do not accord misfires the attention they deserve and they end up paying the price-ignition coil replacement can set you back a cool $300.

What Makes Coil Packs Go Bad?

To understand what ails ignition coils, we will look at some of the factors affecting their lifespan.

Vibration And Heat

Ignition coils are not built to withstand the heat and vibration stresses present in our engine thus the constant breakdown after only a few years of operation.


Like all other components, ignition coils are affected by wear and tear after a period. If your car is second-hand or has a high mileage then a scare from ignition coils should not come as a surprise.

Spark Plug Gap

When the gap between the spark plugs and the leaking valve is too wide, carbon accumulation might occur. Carbon in the ignition coil area can have some pretty adverse effects.

Poor Quality Of Build

Cheap is expensive. Car owners are advised to desist from buying substandard car parts that retail at irresistibly low prices. Cheap and unapproved ignition coils will only last a few months in your car before you have to call your towing service at night.

Should I Replace All Coil Packs At Once?

Well, you can replace one but most mechanics recommend that you replace the whole pack to steer clear of future surprises. This is mostly the case when they haven’t been looked at in a while.

Should Coil Packs Be Replaced With Spark Plugs?

As the two work closely together, your mechanic might suggest a replacement service for both but not always.

 If it’s a routine spark plug replacement service, there is no need to touch the ignition coil but if the repairs were warranted by failures in the ignition coil then you might need to get new spark plugs and ignition coils.

Take Away

Ignition coils serve in the combustion process but in the less talked about areas-they boost the battery’s power so it matches the spark plugs’ needs.

Car manufacturers recommend that you replace your ignition coils after 5 years but not many get past the second year. This can be attributed to harsh conditions under the hood and chemical accumulation around the coils.

There are a few factors that affect how long your ignition coils will last-check them out and take care of your ignition coils better.

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