What kind of engine work should I do?

By the way, while waiting for parts, I suddenly realized one thing, that is it possible to tell if the pistons and rings in my engine has been updated before, by looking at the appearance? I mean, if there's any difference between the new and old design pistons on the top?

 

Looks the same as mine... Anyways the ordered pistons and rings are on the way and should arrive in a couple days. Will replace them.

By the way, as I put the transmission back I had a question about the inverter water pump. I heard the inverter water pump was a common failure part on gen2 but looks like not quite prone to failure on gen 3 so I'm debating if I should get it replaced since I'm already here? Or if it's safe to wait until it fails?

 

Thank you so much! I have access to these documents.

I received the new pistons and rings yesterday and have removed the rods from the old pistons and put on the new ones, as well as installed the new rings onto the new pistons. One funny thing is that when I compared the new parts to the old parts, I noticed that the new pistons are almost identical to the old ones except for the coated skirt. The new pistons have part number 13101-37240 on the sticker on the box, however the pistons have 37130 stamped on the inner side, same as the old ones.

I can definitely see the revised oil control ring design, from a 2-piece to a 3-piece. The two compression rings are the same. I somehow suspect that Toyota did not really revise the piston too much so it might be OK to use the old pistons with the new rings... Not sure if anyone has experience.

 

$35-40? Where do you get it for that cheap?
I guess you were looking at the pump for gen2. The one for gen3 runs at least $100 from most parts supplier from my search.

 

Yeah you are right after a closer look I noticed the oil ring groove of the new piston is much wider. That's great at least I did not waste money buying something same lol!