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Discussion Starter #1 (Edited)
Hi all,

My '07 Limited had this service/recall performed by the previous owner's dealership before I got the car. It totally worked because 50,000+ miles & 4 years later (my ownership) it's not using a drop of oil.

My questions:

1) What exactly does this service entail - mechanically?
2) Does it extend the life of the engine at all?

Thanks!

-kj-
 

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Toyota changed the piston and rings with an improved parts to resolve the engine burning problem. This video has some good information. I am not sure why the 2004-2005 RAV4 did not have this problem but they started manufacturing them in Canada starting in 2006. The new piston and rings was the fix but I don't think Toyota had enough faith in that so they came out with a new engine and hence the 2.5 litre engine was created.
 

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Toyota changed the piston and rings
The "looser" rings are not a defect per-se but a way to reduce internal friction loses between piston and cylinder walls and claim better gas mileage. But more exhaust gases are getting pushed past those rings in the crankcase, increasing the static pressure there and pushing more oil vapors trough the PCV to be burned.

Because of this "eco" design, most of the new cars have horrible piston sealing. If you go to a new car lot and remove the oil cap on a running engine, you will see gas pressure coming out of that hole like it's an old worn-out engine!

And yes, replacing the rings with more stiffer ones will seal better, but if the cylinder wall liner is not designed for this increased friction, it will wear out and make a new gap soon.
 
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