A little bit of "very fine" media, a plug cleaner or blast cabinet and those will be good as new, ready for another 100k
Hmmm. To me, those aren't the original plugs. Too much electrode left. These plugs are most likely the SECOND set of spark plugs; some of the cylinders clearly have oil fouling (some worse than others). Oil fouling could be due to excessive wear of the piston rings & valve guides, due to repeated low oil levels, and/or worn valve stem seals; hope OP investigates worn valve seals at the very least. Assuming the OP is NOT the original owner, some previous owner(s) had the plugs changed near the original schedule: 10yr/120k miles (or 10yr/150k miles).
If you have a tool to gap plugs check the gap on the old plugs to see how wide they actually are, they look pretty wide by the picture.
What’s cool is I don’t see any burnt stuff on the upper part of the plugnfrom weeping valve cover plug well gasket. What an awesome engine this car has.
Hey all! OP here. so the picture was a "from the hip" shot, if you will. The one at the top left was the best looking one and was the right most plug facing the engine. The lower left most plug is by far the worst, and is the hardest to see in the picture. It had a gap of at least 2mm and the center pin was about gone. Plus it looked downright fluffy with fouling. From left to right they went from depressingly worn out to cleanable. I did just buy the car, she still gets just shy of 50mpg with my amateur driving style. The last oil change was 4000 miles ago and was not low. Then again I don't know if the PO was topping it off. Anyway with new fluids plugs and PCV valve it runs 110% quieter. Old plugs were the NGK, new ones Denso. While I was in there I replaced the pcv valve and cleaned out the throttle plate. I looked down the throttle and was actually able to mop up a tablespoon or so of what looked like oil from the bottom of the intake manifold. Any ideas about that?
Ok. So I dug them out of the trash. Here they are. I’m not sure but I think they are in the order they came out. Assuming left most is cylinder one. My only spark plug gauge only goes up to 1.14mm. The wire passed through and rattled easily. So I tried a dime. It fit with room too.
Normal for the Gen2 Prius b/c the engine is an Atkinson cycle engine. You can search for the difference in engine cycle yourself (Atkinson vs Otto). You can also read this: Atkinson vs. Otto Cycle | PriusChat Transaxle fluid probably has NOT been changed either. Use Toyota ATF-WS. Ideally, the fluid gets changed at 30K miles (when the car was new), then every 60K miles. Toyota calls the ATF-WS used in the transaxle a "lifetime," fluid. As you know, NO lubricant lasts forever. Toyota's definition of "lifetime," will be drastically different than the average consumer. See post #473 for some pictures of ATF fluid and a heavy duty magnetic transaxle drain plug.
already changed it, and it was full, but it was *BLACK* as India ink. the magnet had just a little filings on it. Nothing like a manual tranny.
Probably been that way for over 100K miles. If I was writing the maintenance schedule, I'd spec an early transaxle fluid change, around 10K miles or 12 months, then one more around 60K or 6 years. I get the sense an early change has the most benefit (just judging from colour), and with each subsequent change there's diminishing benefit.
BKR5EIX.......definitely not original, or OEM installed, but it is a cross-referenced plug and fits correctly. Spec'd for only 50k miles, as only the center electrode is iridium, and the ground electrode is nickel, with no platinum or iridium insert. Starting gap of 1.1 mm and torque of 18-21.6 ft-lb. https://www.ngk.com/product.aspx?zpid=9311
At any rate, I've only seen worse plugs in a jeep liberty I was once unfortunate enough to own. Did I mention the engine would diesel a few seconds on shutoff?
