Prius c spark change plug

I changed my spark plugs this week @68k, and I can definitely feel the difference. The car’s never driven bad for me, but it’s really purring today. Acceleration is noticeably smoother and more responsive. I’m very pleased. The old plugs weren’t shot.. just old, a little rusty, and obviously a little tired.

The way I see it, why should I wait for 100k, or signs that the plugs are going bad when this only cost me $30 and I put them in myself.

If a spark plug is toast, there’s a decent chance it probably wasn’t performing optimally for quite a while, right? Either way, I‘m really happy I swapped them out, and I’m having fun learning about my car and how to take good care of it.

I’m doing a lot of preventative maintenance tuneups right now so I can keep everything logged at 65-70k in my memory. Replacing the transmission fluid is next.

 

Hi Pris3C,
I had the same feeling when i changed my spark plugs. Engine was fine before, but after the change it felt like butter ultra smooth.
For the transmission fluid change from my experience I would suggest to have a few things ready; a torque wrench with specific washers and a solution to get the fluid in without too much trouble. I went with under the car with a turn pump, some have suggested from topside with pipe going through the gaps.
The way I did it was a bit of a pain especially if not able to lift up the whole car to at least full height of the person working on it.
After the fluid change it was a nice feeling too, even smoother.

 

I appreciate the tips Max. I’ll probably be filling the fluid from below as well, maybe occasionally switching arms so they get an even workout

 

While I was pumping I was wishing i had paid someone to do this. But when the oil started to overflow from the filling hole, it felt like I was free from slavery. Keeping the tube in place and operating a hand crank pump while squatting, that was a good work out.

 

I'm at 117k miles and about to do mine at 120k which is what the manual says is the replacement interval.

It use to be that Denso said no on anti seize but I guess it's ok to use with 30% less torque. Since I'm in so cal we don't have corrosion so need to diced if using some is worth it?

https://www.densoproducts.com/denso-plug-torque-settings

 

I would check the Toyota spec for spark plug torque. Unfortunately there doesn’t seem to be a PDF in circulation; someone will have to take out subscription at Toyota Tech Info to check. FWIW 3rd gen is 15 ft/lb, with clean/dry threads.

anti-seize is debatable, I’ve sorta settled on put some on, wipe it off as complete as you can with a rag (there will be slight residue) and reduce torque to 13.

 

I replaced mine at 157 000 miles! Well actually only 3 of them because was unable to unplug them and the one under the bracket was impossible to reach.

 

Many claim anti-seize is unnecessary. It is still used in aviation BUT they trust their mechanics to not over-do it. Getting any anywhere near the business end causes more trouble than its worth. So if you use it, keep it away from the tip and reduce the torque by about 30%.

I pulled laser Iridiums from a 1ZZ at 100k miles and they looked like new so I gently regapped and reinstalled. They should be fine for another 50k. I wish I had checked the internal resistor while I had them out. They are to read 4-5K Ohm. If they drift higher they should be junked. I'm starting to think that long life plugs will be failing for reasons other than tip wear.

Watch for counterfeit plugs! They are everywhere. Forget FleaBay for spark plugs.
Advance Auto has a good selection

Pulling plugs over 10y is roulette so its good to take a look at them @ 6-10yo to keep them from seizing up.
In cars that are Ok with non-concentrated ignition and you are running low miles don't be afraid to go back to inexpensive copper plugs

If the Denso VFK16 or NGK DIFR5C are much over $10 I'd go with Autolite XP3924. A fine plug at a great price.