Originally Posted By: tennisdoc40
Not an oil question. 100,000 mile service for the Navigator has first Spark Plug change. Truck is running great. Is there any downside to waiting longer, say 10,000k? Just very busy, and then vacation.
Thanks
I'm going to slightly disagree with a few other posters here and say, that if it was my vehicle, I'd replace them. I just get a little leery of the plug seizing to the head. Also, the gaps can get a little larger and they start to wear exponentially. If it's gone this long, however, another 10K won't hurt.