hello me again and i have another girl type question.. my husband doesnt know. we have an 03 altima 2.5s and she has 45,500 miles on her now. when should the spark plugs be changed. my husband nor i can not find plug wires or distributor cap and he is at a loss on how to change them if we knew when to change them. i think i remember the salesman saying something about 100,000 miles on tune ups. is this true any imput would be appreciated.. thank you aprilannette
You'll be happy to hear that your spark plugs will last you 100,000 miles. As long as you keep replacing your filters as necessar (air/fuel specifically). When you replace the plugs eventually you'll notice that they are a lot more money (mine were approx $10/plug for an '00). That's because they are platinum coated plugs and your car needs them to run as efficiently and clean as possible and that's also what makes them last the 100k miles. Hope that helps.
You should see it listed in your maintenance schedule with your owners manual, but Darktide is correct- you only have to change them every 105,000 miles.
They're still very easy to replace... there is no distributor or plug wires. on this engine you have four small individual coil packs- one for each cylinder and a completely solid-state ignition system. you'll see four identical "sensor looking things" in the middle of the valve cover. they will be bolted down with usually 1 or 2 10mm screws and have a small connector on one side- three wires on all of them I've ever seen. simply remove those coils and the spark plug is underneath. change just like you would a standard spark plug. very simple, and no wear items like caps, rotors, or plug wires.
of course, that may all be hidden by the plastic covers over the engine- I've never been under the hood of an '02+ altima so I'm not sure if they have a cover or not.
thank you so much... I really appreciate the info and relieved... we do keep the filters clean and now no worries for at least another 50,000 miles......again thank you
I've read in a few places (Car Talk at least) that it's recommended to at least remove the plugs every 30,000 miles or so, even if you don't replace them. If not, they can be nearly impossible to remove. I know my parents' mechanic had trouble getting the ones out of their Aerostar after 100k miles.
NGK plugs are of a much better quality than the Aerostar's stock plug (Motorcraft). They are also pretty well protected from the elements in the QR25DE engine. I wouldn't bother with them unless there was a reason to touch them prior to the recommended mileage interval, such as a decline in performance.
Most manufacturers use copper plugs from the factory. Their electrodes wear out between 30-45k miles. The Nissan and Chevrolet are 2 that come to mind regarding 100k+ tune-up intervals. Those types of plugs are 10x better. I think I also read somewhere that Fords can throw a CEL if you use certain types of platinum plugs, Nissan also use metal timing chains instead of the lousy rubber timings belts like others (not mentioning any names, of course).
Timing belts are actually a good design and create less dynamic vibration than timing chains. They are used in NASCAR engines and Nissan used them for over twenty years. The problem isn't the belts, but the failure to replace them at their recommended intervals as suggested by the manufacturer. The other problem is that engine compartments are becoming so tight that it can be a tough job to replace on some models.
A lot of manufacturers are using platinum spark plugs these days. In fact, in the last few years, it has become more common to see platinum plugs than copper plugs, especially in "coil on plug" setups.
I would rather have a timing chain myself for the same reasons, but that doesn't necessarily mean that the timing belt driven engines are of a poorer design. The design of timing chains over the last several years has also greatly improved to reduce dynamic vibration. I wouldn't be surprised that in a few years there will be no camshafts or timing chains in new engine designs and the valves will be controlled by electronic solenoids...Now wouldn't that save a whole lot of vibration and weight?
good luck on replacing the plugs yourself.... You can only get to 3 of them unless you remove the upper intake manifold... ok maybe I'm getting ahead of myself... I have an 06 altima.
Needless to say, a lot more work than I expected.
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