Which is the way all of these engines run until they start burning oil. Mine was steady through 125k miles. The subsequent blowby creates more pcv flow and the burned oil dumps more hydrocarbons into the exhaust. Some say Atkinson cycle is a factor in a port injected engine but it has not proved to be an issue on Gen4s used throughout the Toyota line.
Our '10 will likely never get there; it's currently at 102K kilometers, and we're putting on around 3k kms per year. All my prep is cargo cult.
The definitive look at gen3 Prius and Lexus head gasket cause, effect and how to fix it right. This video is a year old but its analysis has aged well. It includes a discussion of oil in the intake. HG Fail Multifactorial Analysis Car Care Nut Spoiler Alert - It’s way more than a cleaned egr system and head gasket swap.
It’s a full engine rebuild, while he pontificates as to why the head gasket fails? I forget, and don’t want to wake the missus (early morning west coast).
The video explains his choices and the issues quite well. We have seen this video before but others have not. Rebuilt is the solution when you have oil consumption. Plus a new egr valve, rebuilt head and ecm software. It is more cost for his shop to clean the intake and cooler than new parts cost. The intake, egr valve and head gasket are revised Toyota parts. He uses a new timing chain and head bolts. Some can get a somewhat equivalent rebuilt engine for $3500 - others can have it turnkeyed for $5,000. His charge of $6,500 is not bad for a new short block, new egr system, new timing chain and new intake. It is the solution a dealer provides for another $1k-$3k.
Thanks Mendel, that is helpful information. The dual collectors is a bit more pricey than I would want to invest at this point, but helpful to know it is possible to reduce oil accumulation in the IM to almost nothing. Also helpful to know that if I ever replace my gen 3, the gen 4 would be an improvement for the carbon buildup problem.
Just a piece of theory: the oil gets to the intake through the intake valves. Remember Prius engines blow more than (or up to) 50% of air and fuel mixture back to the intake at moderate loads. Just monitor MAP sensor readings, whenever it reads around 88% of the atmospheric pressure, it means that the throttle is fully opened and the Maxwell cycle (often wrongly named Atkinson cycle) breaks into. Low-tension rings let [a significant] amount of oil into the mixture upon engine cold start (piston is cold) or high loads at low speeds (piston "tilts", disallowing normal work of oil control rings). This is where we get oil under the throttle body from. The above theory is based on the following observations: - my hybrid Camry 2016 has absolutely dry oil-free intake albeit way higher mileage than 2012 Prius. Camry runs on standard tension rings having barely noticeable oil consumption; - friend's Prius 2022 has dry intake must be the same case as my Camry; - no oil consumption happens if I drive Atlanta-Miami-Atlanta while local commuting means one quart in 5K miles, e.g. between oil changes. I do not have any example of a Prius with pistons and rings replaced according to "high oil consumption" recall. Would not be surprised if those priuses run on dry intakes... PS Just engines enthusiast, not an engineer or a mechanic.
Mine fully fills with water frequently in the winter. In the summer it doesnt. I've probably gone about 3 times where I went to check it and it was totally full of water.All the stuff in the OCC would have just gone into the intake anyways if the OCC wasnt there, so whats the harm in allowing it to get full (other than it not working when its full)? If letting it fill up is worse than not having it, I better remove mine, because I am sure I will fill up a few more times over the years after a long highway road trip. Anyways I have a 15 year old 2010 Prius and no engine issues, oil burning, or coolant consumption so far. Fingers crossed.
I have 2015 updated pistons and rings in my 2010 and there is still oil in the intake manifold. The problem is the pcv that is why people run with oil catch cans. Best way to completely have zero oil in the intake manifold is to do a pcv delete and plug the intake manifold and vent to air. There are two other things to do but I will not get into that until I fully test it out.
The problem is it blocks crankcase ventilation which then pressurizes the oil containing areas and blows seals. The form a gasket timing chain cover seals are the first to go. More recent Toyota engines have a built in catch can in the pcv system which drains back to the crankcase.
This is what my pair of Moroso 85474’s (in series) collected, otherwise would have been delivered via PCV, to the intake manifold. Each is 50~75 cc, in approximately 3k kms, over course of last year: First can is on the left, mostly oil, second can on the right, mostly water. a little bit of oil does spit back front in intake ports as well.
Another 10 thousand kilometers and so much will accumulate that you won’t need to go to the store for new oil.
Hopefully that answered a lot of people who asked on the board there, why don’t cars come with oil catch can from factory.
Wow...honestly I can't imagine an owner not checking/emptying it out during their 5k OCI ..and I'm not intending to start an argument on the 5k OCI itself LOL
