Oil Catch Can, Eliminate that knock!

I've read articles, watched video's and personally witnessed the prius’ infamous cold start engine knock.
I owned a 2005 prius (sold) and recently acquired a 2011. My girlfriend owns a 2010 prius.

I noticed a lack of oil in the engine while doing a 10k oil change on the 2010 with 80k miles on the clock. After inspecting the pcv system, I discovered a trail of oil in the hose along with two tablespoons of motor oil in the bottom of the throttle body. THIS IS NOT NORMAL!!! . People have said this is normal - This is absolute craziness - This is not a 2stroke engine where oil is mixed with gas to lubricate and cool pistons.

Oil, Fuel(excessive), Water are incompressible solids, and when in the combustion chamber, will make the motor knock running on 87 octane. Incompressible solid = increased combustion.

Ever put 87 octane in a turbo charged or high compression/performance engine and driven it??? Loss of power and knocking is the result of pre ignition, this happens before the cpu can tell the spark plug to fire. 92 octane stops this because it needs higher heat to ignite.

I used to have a 300zxTT and when my ex put 87 octane in it, I ended up having to put octane booster in the tank to fix the pre ignition.

The prius runs on 87 octane, but higher grade octane or boosters will not fix the knock. The prius needs an Oil Catch Can (OCC).

The pcv hose that toyota put on the block it too low and too short. Engine oil is pushed into the intake plenum, where it builds up, and then sucked into the cylinders upon start up. This is bad!

Crankcase pressure is the engine’s hot air being produced by the friction during the combustion cycle. Higher mileage prius engines experience blowby because when rings wear out, they cause the combustion gases(fuel) to flow around the rings and increase’s that crankcase pressure x2.

This blowby pushes oil, water(condensation) and fuel into the intake plenum from the pcv. If anyone has taken apart the throttle body and seen the oil, it is because of the blowby. During the cold/humid months you will notice that the intake plenum has white/milky oil, this is caused by condensation contamination. Oil and water in the combustion chamber on colder/humid month start ups is were people are experiencing this engine knock/pre ignition.

An Oil Catch Can will filter out the majority of oil/water and prevent the cylinder from knocking. I change/check the OCC every oil change on the 2010 prius and find about two table spoons+ in 10k miles. During the cold/humid seasons, I would highly encourage you to check the OCC weekly due to more moisture buildup in the crankcase.

In the winter, water in the OCC will freeze and stop the OCC from doing it's job. Our 2010 prius has not had a cold/humid knock start since the implementation of this OCC. It has been on the prius since 80k and now has 107k miles (1year1/2). This investment can cost as little as 15-150$, some are way over priced obviously.

The 2010 is using a ball jar, because it was an experiment. Other car manufacturer's have thier pcv valve’s on top of the valve cover. Like my Ridgeline. These engines do not push as much engine oil into the intake/cylinder's because it is so high on the motor. The 2010 prius has two crankcase vent's, one on the valve cover(no pcv) and one in the middle of the engine block(with pcv).

The naturally aspirated motor (NA) runs @ 14:1 compression ratio with computer making micro adjustments for smooth operation. 14 parts air and 1 part fuel. When fuel/oil/water are introduced to the air ratio, ignition is not stoichiometric.

When I rebuilt the 2011 prius' engine I did not see any oil/condensation build up on the valve cover crankcase vent. I did however found oil sludge buildup (not carbon) on the pcv hose and bottom of the intake plenum. I will show you the two OCC on the prius’s we have.

I know that the toyota has done nothing to solve this problem. The tsb was a temp fix because the intake plenum was clean/new. These are my findings to why the prius has a rough idle problem. If your car has a blown head gasket and or clogged egr or any other problems, well that is in other threads.

Million dollar question is, Could this engine knocking problem lead to a BLOWN HEAD GASKET???
HELL TO THE YES
So could a lot of other things.

2011 Prius Oil Catch Can OCC found on amazon/eBay. The 3/8 hose is from Home Depot/Lowes. The mounts are 3d printed by me.

 

2010 Prius OCC ball jar

5k miles of build up @ 107k miles on motor. Ball jar with steel wool inside.


Throttle body opened up for the first time since 80k miles with 107k currently. Approximately 1/2 teaspoon. No knock.

Sorry it was a getting dark outside and while I was writing this I ran out to take pics.

 

Break down of how system works

 

I have thought about blocking the lower pcv valve and installing a pcv valve on the valve cover.


Integra gsr stock pcv valve system.

Integra gsr welded and threaded valve cover mod

 

The other benefits to having an OCC is a cleaner intake plenum, intake valves, piston heads, cylinder heads, exhaust valves, header, egr cooler, cat and probably lower emissions.

 

Two heads are better than one! There were definitely a handful of people that had mentioned they were going to do it but no posts. I never thought that this car needed it because most NA cars do not need it. There is a design flaw and when I did the motor rebuild, I did not like what I saw. The evidence is clear to me. Thanks for your comment. I just hope we can save some prius' from some expensive repairs and get that legendary toyota reliability back on track. I think it is a great car. My motor is not even broken in and I was driving around all day without a lower engine cover(bad4aero)and still hit 58.7mpg
Trying to make it to the million mile club man!

 

Yes and no. Yes, Valves are what bring fresh air in on intake valve using a very efficient scavenging method. No meaning that not one but two crankcase openings supply scavenged air, along with the egr. The word scavenging is better to describe how a 2 stroke engine works or the older style combustion engines, Both crankcase vents are technically recycling its air from blowby . Where the egr is controlled by a valve, usually open at cold start. The crankcase use to have breather filters on them and exhaust gases were pushed straight out into the tailpipe. These laws make you recycle the gases to reduce emissions while throwing back the carbon soot and oil all over clean engine parts making new problems. There are interesting articles talking about the efficiency increases with direct injection and all the problems that come with it. click on direct injection for the article, you really have to watch what you buy these days because the manufactures are saying Gotcha Bitc$ and are letting the consumer suffer by do their R&D

 

Vented oil catch cans are not emissions or carb compliant for the newer cars on the road. Venting these gases into the atmosphere will also wind up back in your cabin while driving. The prius may throw a code if it is vented because of a vacuum leak. The oil catch can I bought had a vent option with filter and included the screw to block it off. You can see in the first pic that I blocked it off. Some oil catch cans do not have baffles in them and will not catch as much oil/mist, water, fuel back into the system than cans with baffles. The more baffles it has the more it will trap and redirect the oil straight down. Some people are putting stainless cleaning pads in the catch to baffle/trap the oil mist.

This is the same oil catch can I have and even has a little dip stick to show the level of debris inside.
You can see someone gave it a bad review because he used the vent/filter option and his engine lost vacuum, so it started running rough and he gave it a bad review. He obviously does not know how engines work.

 

There is no ill effect on longer tubes. If it's loose you will get a vacuum leak of course.

Money, If your car was clean and never broke, there would be less service/maintenance and repairs. One of the reason Ford has done so well for so years and did not need a bail out is because there equipments breaks down frequently. Ford generates money from internal financing, equipment failure, brand loyalty etc. Ford spends more money in advertising and uses the consumer as the guinea pig to test out there products. Ever wonder why they discontinue so many engine's, transmissions etc. Not to mention mid year changes. I have a lot of respect for Toyota because they put the majority of there money in R&D with honda right on it's heels. My old mechanic neighbor hated working on fords because he would always get the wrong part to fix his customers cars. I could hear him screaming 4 garage bays down and would bring him beer and talk shop. He would order the correct part per year, but revisions made it late to 3rd party part suppliers like bap geon, fisher, parts plus, car quest, advanced, auto zone, orielly etc. Mechanics hardly ever use factory parts because they are overpriced and out of stock. Vehicles on a lift need to move or they loose money. Those new ecoboost 2.7 and 3.5 engines are junk!

Auto industry is not doing so well right now. Ford did just lay off a ceo and 1500+ employees with 20,000 projected. Unpaid subprime auto loans are @ a 20 year high right may pop like the housing market. I bought the prius because fuel prices may skyrocket this year and economy may turn. Ridgeline's avg fuel/17mpg is the suck.

Turbo charged cars and high compression engines will push more debris through the pcv/egr system and consume more oil than a naturally aspirated engine. Driving any of these cars hard intensify these symptoms. If you drive a car around a race track and flog it all day and wait 3k miles + for that oil change, you are asking for a blown engine due to a lack of lubrication/contamination. Oil should be checked while refueling to insure proper levels so there are no surprises. This is what bugs me with my girlfriend, she just drives it knowing I will just fix it
Ford ecoboost normal weather

Ford ecoboost winter weather

 

The corolla would consume more oil because you have to squeeze every drop out of the 1.8 to get it going. The prius uses the same engine without a vvti on the exhaust side and generally runs @ a lower rpm with electric assist. In the tour de france they caught cyclist's motor doping with electric motors in the frames giving them an edge. The prius is electric motor doping and uses less oil than the corolla.
If i was to clean out the throttle body every oil change I would have need to have an oil catch can in place.
I've read several people saying it is normal. Im not trying to point any fingers here. The article neglects to show that oil is coming from the pcv system and also does not mention egr debris. The atkinson cycle does not do leave intake valves open during compression stroke for the full range of engine rpm's hence a vvti solenoid to control this cycle.
Dual vvti 2010 corolla


If this were the case toyota would not need the vvti solenoid or hydraulic controlled cam gear and just use a a regular cam sprocket if this intake valve was to stay open partially during the compression stroke.


The intake plenum, heads, valves, pistons, injectors and egr etc is what gets gummed and car will run like crap. YOUR CHOICE!

 

I'm willing to bet they are, consumers have benefited from less maintenance in modern cars. Older car technology had copper spark plugs lasting 20k miles, distributor caps lasting 30k miles, tires lasting 30k miles, transmissions would fail pre 100k. Carberated systems never ran well and constantly had to be tuned. Cars used to have ice in a tube hanging off the window to benefit from chilled air in the car. "Pull over hon, we need more ice"


Modern diesel engines need urea and people that I know do not seem bugged to buy it. Ford has a factory made oil catch system as an option. If you READ about direct injection problems, you will see that consumers are going to have to do additional maintenance no matter what. Walnut shell blasting service, Can we train squirrels to do this in the exchange of bird seed? Modern cars have an in cabin filter and that is additional maintenance. Tesla has a hepa filter. Air conditioning is a modern convenience with a price that people are willing to pay when it breaks down. Have you ever paid for a new A/C compressor at the dealer for a gen2/3 and paid to recharge it. I can buy a used car running for that price! Something that needs cleaning/replacing and parts wearing out in the effort to keep the car running is all considered maintenance.

Dumping an oil catch system takes 2-10 seconds! This is the least of my problems. The stupid cover on prius to change oil, stupid wrench adaptor that gets stuck on plastic filter cap, rotating tires every 5k, draining/filling coolant/tranny and removing windshield cowl to get to spark plugs is where the time is waisted. It's all the joys of owning a prius. Better than owning a tdi and having the dealer say 400$ please for a transmission fluid change that can only be done @ the dealer with a special machine, no thank you. I like to do things myself. I am happy to have an OCC in the car because I like the things I buy to last a good while, neglecting maintenance is asking for car problems. The prius still puts a smile on my face when I see 50+ mpg.