I picked up a used 2004 Chevy Impala, and the complaint about the vehicle was that it needed a tune-up. So the 1st thing that comes to my mind is how do I change the spark plugs and wires on a 2004 Chevy Impala? Here is what I researched and found.
Step 1- Wipe down the work area and spray debris away with compressed air from a blowgun.
Step 2- Remove the spark plug boot using your spark plug boot puller
Step 3- Remove the spark plug
Step 4- Check the gap of the spark plugs, not all spark plugs come pre-gapped from the factory.
Step 5- Install the new spark plug and torque to correct torque spec.
Step 6- Install spark plug boot and do not forget to apply the dielectric grease in spark plug boot before install.
Step 7- Reattach anything you took off to access the spark plugs and spark plug wires, you are complete.
Tools Needed for this repair and their links to Amazon in case you need the tool.
⅜” drive ratchet
6″ extension
Spark plug socket
Gap gauge
Spark plug boot puller
Torque wrench
Dielectric Grease
The tools that you are going to need is a ⅜” drive ratchet, a gap gauge, 6″ extension, spark plug boot puller, torque wrench, dielectric grease, and a spark plug socket. The front three cylinders are going to be the easy ones to reach, but the back three are going to be a bit more complicated. What I found is that if you follow the spark plug wires to the spark plugs, you can remove the rear three by hugging the engine and going by a touch of the hand.
The entire job from start to finish should not take longer than 45-75 minutes. This particular job is rated at an automotive repair shop to take 60 minutes. So if it takes you a little longer than that do not worry because the back three spark plugs can be stubborn at times.
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The spark plug wires should quickly come off of the spark plugs if dielectric grease were correctly applied, the last time the spark plugs and wires were done last. Not everyone uses the dielectric grease, but this will protect your electrical connections against any corrosion and moisture that could hinder your electrical spark.
In the picture to the left, this is what can happen if you do not use dielectric grease when installing the spark plug wires. The inside boot of the spark plug boot came out of the spark plug and made this spark plug very difficult to remove.
Do not over apply the dielectric grease though, even too much of a good thing can be harmful. You want just a light coat in the spark plug boot. But by applying this will decrease the chance of any misfires and also make it a lot easier to take off the spark plug boot the next time you need to tune up your Impala.
When should I change the spark plugs and wires in my 2004 Chevy Impala?
All spark plugs are different when it comes to the replacement interval. Here are a few of the most common spark plugs and their mileage replacement interval. Remember when it comes to spark plugs the higher the mileage replacement interval is, the more in the spark plug is going to cost due to the metal that they use in the construction of that particular spark plug.
NGK– 40,000 to 50,000 miles
NGK Laser Iridium– 80,000 to 100,000 miles
Bosch Platinum– 60,000 miles
ACDelco Iridium– 80,000 to 100,000 miles
Bosch Iridium– 50,000 to 80,000 miles
Autolite XP Iridium– 100,000 miles
Denso Iridium TT– 100,000 miles
Bosch Double Platinum– 80,000 to 120,000 miles
ACDelco Double Platinum– 80,000 to 120,000 miles
Autolite Double Platinum– 80,000 to 120,000 miles
You will start to notice a lack of power in your engine due to spark plug wear from the mileage. This is a clear indication that your spark plugs are either coming close to needing to be changed or are past their time to be replaced.
Your spark plug wires should be changed when the spark plugs are replaced. But if you look into your owners manual for a 2004 Chevy Impala, it states that the spark plugs and spark plug wires should be replaced no later than 100,000 miles as per manufacturer.
Now if you bought spark plugs that have a lifespan of 30,000 miles, of course, this will be a different mileage that you need to change your spark plugs at. If you purchased a low mileage spark plug and changed the spark plug wires at the same time. At the next interval change the spark plugs but not the spark plug wires.
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Why should I change the spark plugs and wires in my 2004 Chevy Impala?
Think about your spark plugs as the energy that drives the heart to your vehicle. The spark plug wires are the roads that this energy travels on to meet with the air and fuel mixture that awaits this energy in the engine’s cylinders.
Without the proper amount of spark, the fuel and air mixture cannot combust, causing the power needed to have the engine run properly.
Even though the spark plugs are one of the cheapest parts, you can 
purchase for your vehicle.
These small parts play the most vital role in your vehicle’s operation. So ask yourself why should you change the most essential element in your car that will give you the best performance and fuel mileage your vehicle is capable of?
Remember to match the firing order of the spark plug wires to the spark plugs. On the left side is the firing order for a 2004 Chevrolet Impala 3.4 Liter V-6 VIN E Engine
Once you state the question like that, you will come to the answer and realization that I did, and that is to make sure that these parts are properly maintained at the correct maintenance interval. By doing this, you will receive the best fuel economy and engine performance from your Impala.
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What should I change my spark plugs and wires with my 2004 Chevy Impala?
⅜” drive ratchet
6″ extension
Spark plug socket
Gap gauge
Spark plug boot puller
Torque wrench
Dielectric Grease
You will be able to change your spark plugs and wires with these tools listed. Remember with the spark plug boot color you want to go as far down the spark plug boot has possible to get a firm grip.
Also, remember left is to loosen and right is to tighten when taking the 
spark plugs out. You do not want to over tighten the spark plugs; this can cause a misthread in the cylinder block and is an expensive and time-consuming repair.
With year torque wrench once the torque wrench clicks or bends at the head of the torque wrench depending on the torque wrench that you are using, then you have reached the proper torque amount and are all tightened down.
When installing your new spark plugs, you must use the proper amount of torque. To find the torque spec that you should use you can refer to the manufacturer’s website. Here is the torque spec on the Chevrolet Impala to save you some time.
Eighth Generation (2000-2005)- Spark Plug torque spec 11-15 ft lbs. (15-20 Nm) Gap spec is 0.060
How does changing my spark plugs and wires affect my 2004 Chevy Impala?
Remember your vehicle needs a few things for it to operate correctly. Your car needs fuel, spark, air, compression, and timing. Your spark plugs play a vital role In your engine functioning correctly.
Faulty spark plugs can cause your engine to create a misfire in one or multiple cylinders, depending on how many spark plugs fault out. What good is an engine that has no spark? The more mileage that you put on your spark plugs decreases the lifespan of the spark plug themselves.
When this happens, it will affect your fuel mileage and engine performance. So by keeping your spark plugs appropriately maintained, you will increase the performance and quality of your engine.
Thank you for reading my article. I hope it helped you with your spark plugs and wires on your Impala. I hope to see you reading my next piece!
