2007 Toyota Camry XLE Ignition Coils

electricblue3414

Greetings! I have a 2007 Toyota Camry XLE that is in otherwise excellent shape and smooth running. It has relatively low milage given how old it is (117K). Back at around 70K, I had my ignition coils and spark plugs replaced. I dont recall the details of which coils were problematic, but it was enough to cause some awful misfiring and performance issues, along with the check engine light. Ever since that repair, all has been back to normal without any problems.

Since this is one of the only issues I have ever had with this car, can my mechanic pre-emptively inspect my ignition coils to see what kind of shape they are in? Is this a diagnostic that can be done before they fail altogether? I'd like to head off any future issues like I had at 70K when they failed. While I'm not proficient with ignition coils, my research point to a close relationship between the spark plug health, driving conditions over time (wear and tear) and the quality of ignition coils in your car. I'm sure there are other factors. I'd like to get an idea if my current coils are in good shape or if I'm looking at trouble any time soon. Any knowledgeable response on this topic is appreciated. Thanks in advance!

thecardoc3

There really isn't much that can be done to tell in advance whether a failure is imminent or not. What you "could do" is plan to replace the spark plugs and the coil boots (if they can be replaced separately from the coils) before a problem arises as regular maintenance. 50K miles is plenty for spark plugs even though many of the double platinum and iridium plugs can go further. The problem is you just don't have any way of knowing how high the secondary voltage (spark demand voltage) can get before it results in a coil failure. (Secondary voltage is what actually causes the spark to occur across the spark plug and normal is close to 14,000v) Fresh plugs with a smaller gap would help keep the spark demand voltage on the lower side, maybe 12,000v-13,000v for a while.

electricblue3414

@thecardoc3 Thanks for your response! The details you provided make sense. Since this is an older car that still has a lot of life left in it, I plan to keep it for as long as I can as a secondary vehicle. My last maintenance cycle yielded a clean bill of health for the car, but just trying to stay ahead of any issues I had in the past other than normal wear and tear.