Sparkplug replacement at 200,000 km (pictures).

I was going to post both the plugs and v-belt replacement photos in the other thread, V-belt and plugs, 200,000 km maintenance. (pictures) | PriusChat, but that post got a bit long winded so I'll make a new thread.

- The only prep work required for the plugs change is to remove the two bolts and temporarily relocate the relay box from the rear of the engine bay. I gently bent it out of the way and relocated it adjacent to the inverter coolant reservoir as shown in the second photo below.



- With the relay box out of the way I disconnected all of low tension leads to the ingiters. These low tension connectors are very easy to remove once you get the right technique. Press down firmly (finger and thumb) on the little tab at the back of the plug as shown below. When you do that you notice a little gap opens up near the front of the plug where I've shown "pry up here". Now just place a small flat bladed screw driver in that little gap and gently pry it upward to release the connector. Don't over do it or you might break the tab. It only requires a bit of gentle prying and you can wiggle the connector off very easily.



- As you can below, the area around the igniters is quite dirty. I wanted to clean up a bit here before removing anything further, to minimize any ingress of crude into the spark plug wells. So though it's only really necessary to completely unplug the leads from cylinder #4, I decided to remove all four to make the clean up easier. Honestly I'm glad I did it this way. The removal is extremely easy and it gives you more working room which allows you do a better and cleaner job on the spark plugs.



- I cleaned up as much as I could with an old paint brush and then used a bit of degreaser and paper towel.



- Here it is fully cleaned up. Now just remove the ingiter retaining bolts as shown below and remove all four ignitors (they wiggle out quite easily).



- At this point I stopped taking pictures, but with the igniters removed it's a very simple job to insert a 5/8" (16mm) spark plug socket (with a 5 to 6 inch extension) into each plug well and remove them one at a time. None of mine were too badly seized. I did use a cheater bar for a bit of extra leverage on #1, but the other three weren't too difficult.

- Make sure the new plugs are gapped 1.0 to 1.1 mm and screw them in. If you've managed to keep everything nice and clean then they should just screw in finger tight all the way down until the washer/gasket start to mate. Then just torque them to 13 ft-lbs, replace the igniters and connectors and you're done.

Finally here's what my old plugs looked like. Not bad considering they'd been in there for 200,000 km. BTW, my originals where NGK but I replaced them with Denso. Either is fine as long as they are the correct iridium type. (Denso SK16R11 or NGK IFR5T11).


BTW. I did these at the same time as the v-belt. Photos here: V-belt and plugs, 200,000 km maintenance. (pictures) | PriusChat

 

No Freyd, the only thing I needed to move was the little relay box.

BTW. There may be some slight differences around the spark plug area in the non North American model prius. From what I've read here it sounds like there's more obstructing the PCV valve in the American model. If you look at the 5th picture down (the one with the paint brush) you'll notice the PCV over at the right edge of that photo fairly well unobstructed with just the relay box gone.