First Plug Change Report

[alvocado]

I did my first plug change this past weekend with 87k miles on my '02 Yukon Denali. Since there is always lively discussion on when to do a plug change, I'll share my observations. The plugs I pulled were dual labeled NGK PZTR5A15/AC Delco 12567759. These were the factory plugs so keep an open mind if you feel that the original Delcos are the only way to go. I wasn't motivated enough to pull a plug before ordering the replacements so I bought the Delco Iridiums (#41-985). They were actually about $3/plug cheaper than the NGK platinums that I pulled out on Rockauto where I ordered.

 

The original plugs were actually in pretty good condition with no signs of worn electrodes. The outer electrodes were white in color which is normal but showed no signficant signs of wear or damage. The plugs came out incredibly easily and actually surprised me considering the truck is 5 yrs old. It was more difficult to pull the boots than to remove the actual plugs and working around the steering column was a PITA.

 

Net, I do feel that the truck accelerates more smoothly and has more power, consistent with how it felt when newer. I would be stretching to say it's a result of the Iridium plugs over the platinum and would attritube the improvement to just replacing parts that were less efficient due to wear. Since I can notice a difference, I'm glad I did it despite having about a year before I hit 100k miles. I was getting paranoid from the stories of others who had trouble getting plugs out after several years but in my experience, this wasn't an issue. So, if your wife drives the vehicle, wait until 100k, otherwise, swapping them out a bit early would likely have a slightly noticeable improvement.

 

Best of all, it was an hour of quiet time in the garage with no screaming kids:)

[C & A s Dad]

Allen, your finding of NGK plugs in your 02 is understanable, NGK supplied GM for apprx a 3 year period and if I am not mistaken the 02 sensors in your truck are NTKs supplied by NGK as well.

 

I am assuming you did not replace the wires? If not, you should consider doing this. The wires are typically damaged internally if not externally due to the dificulty in removing them. If you do, I would suggest a really good quality wire from an OE supplier. Our (CARQUEST) premium wire supplier is Prestolite who supplies almost 70% of all OE mfgs. There are other good wires out there, just do not go the economy route. Also, if you change them, get some dielectric grease and apply a thin coating to the inside of the boots to make removal easier next time.