How Often Should I Change The Spark Plugs (GM 4.3L, 5.0L, 5.7L)

Sooner or later, the spark plugs in your 4.3L V6, 5.0L V8, or 5.7L V8 Chevy pick-up (van or SUV) are gonna' wear out and are gonna' need to be replaced.

But, in a lot of cases, the spark plugs will be have to be replaced before the recommended interval. Since, quite a few things are involved in determining when you should replace them, in this article I'm gonna' explain a few of them to help you out.

What Causes Spark Plugs To Wear Out?

In a nutshell, the thing that will wear out the spark plug, is the spark that has to jump from its center electrode to its side electrode.

By the time the spark plugs have worked flawlessly for thousands of miles under the extreme temperature they're exposed to inside your engine's cylinders, the spark will wear out even the most durable metals on the planet.

And well, this is normal. Changing the spark plugs is just part of the vehicle ownership experience (whether you do it yourself or you have a shop do it).

When Should I Replace The Spark Plugs?

The cool thing is that you don't have to replace your spark plugs very often (like for example: every time you change the oil). Spark plugs can go years without having to be replaced. Of course there are exceptions to every rule.

Chevy pickup and SUVs covered by this article use platinum spark plugs and these bad boys don't have to be replaced very often.

As a matter-o'-fact, these platinum tipped spark plugs are usually billed as lasting 100,000 miles- but this may not apply to your vehicle.

Now the bad news is that the 100,000 mile replacement rule only applies if you're driving with a brand new engine in your pickup or SUV. Yup, the only time they're gonna' last 1000,000 miles was when you're Chevy was brand new and you drove it off the lot with 5 miles on the odometer.

If like most folks, your Chevy pick up, van or SUV's 4.3L V6, 5.0L V8, or 5.7L V8 engine has over a hundred thousand miles, then you're gonna' have to replace them at a much smaller mileage interval.

This doesn't mean that, because your engine has a lot of wear and tear, the spark plugs are wearing out faster. No, it simply means that the older the engine gets, the more likely the spark plugs are gonna' get plugged up with carbon from oil burning in the cylinders or from additives added to the fuel.

So when you should replace the spark plugs? -Here are my recommendations:

If your Chevy or GMC pick-up or SUV's engine is burning oil: You'll need to check the spark plugs when the engine starts to miss (or misfire). More than likely, you've got a spark plug that has it's air gap (between the center and side electrode) plugged up with carbon.

This means you could be replacing the spark plugs in a few months or maybe in a year.

If your Chevy or GMC pick-up, van, or SUV's engine IS NOT burning oil: Then more than likely you'll be able to go the 100,000 miles the spark plugs are advertised to last.

Depending on how many miles you put on your vehicle, you may be replacing the spark plugs anywhere between 3 to 6 years.

Which Spark Plugs Should I Buy: AC Delco Or Brand X?

The factory original spark plug, for all GM vehicles, is the AC Delco spark plug. But the answer to this question depends on two things:

If your Chevy or GMC pick-up, van, or SUV's engine is burning oil: Then this means the engine in your vehicle has a lot of miles and a lot of wear and tear! In this case, buy the cheapest platinum tipped spark plugs (even if it's Brand X spark plugs).

Using the most expensive ones (whether they're AC Delco or not) will not make a lick of difference, since the engine is burning oil and they're gonna' get fouled up with oil/carbon pretty soon and cause a misfire.

If your Chevy or GMC pick-up or SUV's engine IS NOT burning oil: Then buy the regular AC Delco platinum tipped spark plugs. This is your best bet to have the best engine performance possible.

Can A Spark Plug Cause A Misfire And Misfire Trouble Code?

Spark plugs can cause a misfire condition and a misfire code (P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, or P0308). There are two specific reasons and I'll elaborate:

Internal mechanical problems are causing the spark plugs to get fouled up with gasoline or carbon.

The most likely causes are:

• Engine burning oil due to bad piston oil control rings or bad valve stem seals.
• Fuel injection problems causing the spark plugs to get fuel fouled.
• Ignition system problems causing a lack of spark to a specific spark plug.
• Low compression problems in a specific cylinder and causing its spark plug to become fuel fouled or carbon clogged.

Human error causing the spark plug to malfunction.

This is usually caused by spark plug installation problems such as:

• Breaking the spark plug's insulator (the porcelain part) when tightening the spark plug.
• Dropping the spark plug and breaking its insulator.
• Dropping the spark plug and closing the air gap between the center electrode and the side (ground) electrode.
• Not checking the spark plug's air gap.

More 4.3L, 5.0L, 5.7L GM Tutorials

To see all of the 4.3L, 5.0L, and 5.7L specific tutorials, go to: GM 4.3L, 5.0L, 5.7L Index Of Articles.

Here's a sample of the tutorials you'll find in the index:

• How To Test The 'Spider' Fuel Injector Assembly (4.3L, 5.0L, 5.7L).
• Troubleshooting The Fuel Pump (GM 4.3L, 5.0L, 5.7L).
• Coolant Leaking From Intake Gaskets (GM 4.3L, 5.0L, 5.7L).
• How To Diagnose Misfire Codes (GM 4.3L, 5.0L, 5.7L).
• MAP Sensor Test (P0106, P0107, P0108) (GM 4.3L, 5.0L, 5.7L).