Gen 3 Valve Seals - The Definitive Source of Oil Burning?

I just finished my HG 1,100 miles ago replacing the seals in the process.
Even at 248k I wasn't using much oil before the work so I don't think I can contribute much to this convo. I was def less than a quart used in 5-6k which is remarkable really.
At 1,100 miles now I'm looking like I'm maybe down a whisker on the dip stick so far...not much used at all. I'm guessing way less than a half a quart by my next oil change.

SM-G981V ?

 

Its pretty clear the piston rings are the number one cause of oil burning in 2010-2014 Prii. High rates of oil use is often seen in the 2012-14 as well, they are just newer with less reporting compared to the earlier models. Toyota acknowledged the problem and even changed rings free for the warranty period. Valve seals can be a problem in a variety of engines but is not a silver bullet for the gen3s.

I would not buy a used 2010-14 gen3 unless $5k in repairs have been done or you are ok with doing same down the road.

 

Same! I’ve noticed gen2’s are going for the same price, and sometimes more than a high mileage equivalent gen3 in the used market.

Gen2 isn’t perfect, and has its problems like the other older car. But definitely more robust.

 

I purchased 2014 Prius with ~ 200k. Supposedly the dealer claimed a blown head gasket as reported by seller.

I was prepared for head gasket job. Could find no signal of dealership report. Removed, cleaned, reinstalled EGR cooler forward to head. Burning about 1 qt 1750 - 3k contingent upon driving aggressiveness.

Surprisingly, I now show +50k (250k) and am just now getting start up knock. For the first time in 50k miles the coolant bowl level dropped.

Here’s what I find.

#1 steam cleaned. My bet it’s been enjoying the steam shower for more miles than I knew. The vehicle wasn’t started post 1st signal of knock. I am no subject expert on carbon head steam bathing … my guess is one time would not have obtained a clean result.

Head is at shop for the $125 flat mill. Valves left in. Upon return I will remove the valves to evaluate seals. Will test with copious fuel to check for leak prior to disassembly. Lap reposition. Reading above, the oil burn consensus appears to be be a ring issues. Oil pan looks to be a challenge to drop with block in car. Otherwise, hone and new rings in order. Has anyone, or CAN oil pan in situ, be performed?

I’m cleaning EGR cooler, etc until I retrieve the freshened head. FelPro blue head gasket waiting on deck. Wait, the Rangers just won the World Series for the first time in franchise history! No one is on deck anymore.

Side question, does a device exist to check cylinder compression? I may have to take an old plug and center mill an opening to offer a home for a pipe to connect both a static and dynamic gage.

Many thanks for dialogue.

 

Yes, but you should keep the oil pan in place and drop the crankcase assembly instead.