My 2003 Maxima SE has 68k miles on it. Never had problems with it and it seems to run just fine at the moment. Power sometimes seems to decrease a little and car feels underpowered ....then it's fine again - i always blame this to hot weather. (80 degrees+) Gas mileage...in mixed driving conditions (city/hw) is always around 20-21 and i drive mix of agressive/smooth.
No other issues, excpet that sometimes i can hear some engine pinging.

Now.....at this mileage, should i attemp to replace my spark plugs? I purchased some Denso Iridium 6-7 months ago and i have them ready.

IS it too early to do the sparks?

If i decide to do it....how long should i expect this to take me?? I have print outs of all spark plug replacement write ups and i am familiar with the whole procedure. I've never done it though, on a 3.5 Maxima. I do have some mechanical background (worked on German cars) and i'm going to purchase a nice full set of metric tools/sockets tonight. Given all this....how complicated and time consuming is this job on a scale 1 to 10 (10 = takes really long) ?

I have only my Sunday open....so if it's not super hard and time consuming, i may do it. ...

Any tips/comments?

Thanks!

 

good luck with the manifold.

 

68k is not too early for the plugs. i know nissan advertises no tune up for 100k but what kind of enthusiast leaves plugs in for that long. the plugs are on the 3.5 are slightly more time consuming than the 3.0 because you have to remove the manifold to reach the rear facing bank. the front 3 three should go down in no time at all. make sure to have a magnet rod to get any of the coil bolts that have a tendency to fall. i would have also have some high temp dielectic grease for the inside boot of the coil and anti seize for the plugs.

 

labor time is 2.3 hrs...

 

skill level is 'C', with E being easiest and A being hardest...

 

Why not? You can always change them early.

 

ummm, if u plan to keep the car i say do it, its not like ull get a whole lot of power but should feel smoother and more responsive on the butt duyno, and ull have that satisfaction of new plugs n all, plus likely never have to think bout it again. i still cant believe u have to remove the manifold on the 3.5, y did that design it that way??