Had a coil go out on my son's Scion tC yesterday.
Showed my son how to figure out if it was a coil or plug (or wiring) by moving the coil.
Got a cheap set of replacements of Amazon delivered today.
Had him change it so he can learn more about car maintenance.
I know cheap coils are a crapshoot, but figure I can get 4 cheap coils for $40 vs at least $90 for a single good coil.
It takes less than 5 minutes to change a coil on this thing, so just keep an extra in the car with a 10mm socket and a cheap code reader if it happens again.
With 156,000 miles on what I am guessing are original coils, chances of another one going out are high, so having a few spares is nice.
My daughter also has a Scion xB with the same motor, so can use it on that if needed (she only has 85,000 miles on hers though).
I was told when I got the vehicle that a tune up had been done on it, and almost did not pull the plug, but decided to since it had a misfire on it. Glad I did.
The far right plug was what was under the bad coil, but all the plugs needed to be changed for sure.
While I am not sure if these are the original plugs, they were not changed 10,000 miles ago as the previous owner implied.
Car runs great now, always had a little stumble to it at idle, but that is gone now.
My son says it feels peppier now as well.
I went with platinum plugs instead of OEM iridium. 4 Denso platinum plugs were $14 out the door, vs $10 each for iridium.
I was going to go with copper since plug changes are so easy, but the platinum was cheaper than copper at Auto Zone (I refuse to order plugs online, too much counterfeit issues and hard to return a plug damaged in shipping), Advance Auto had some iridium on sale for $2.50 each, but no nearby stores had any in stock.
Little side note, my son is starting to understand why I do maintenance myself.
He brought his girlfriends grandmothers suv to Take 5 Oil Change (she refused his offer to change it) and was shocked that the oil change was almost $100 with synthetic oil. He knows I have about 30 gallons of synthetic oil in the garage that I spent maybe $120 on all of it.
He asked how much it would have cost to bring his car to the shop and have it fixed, and told him at least $300, if not more ($60-80 diagnostic fee, minimum $100 for the coil, $40 for plugs, and probably an hour labor).
He was like "but it did not even take 30 minutes and $60".
I had to remind him that I had to purchase a code reader and tools, so there is the added cost of that, but over time, that cost is minimal compared to the saving of doing it yourself.
He is about due for brakes (already have pads) so he wants to know how to do those as well.