Catch Cans - LOL
Lexus Champion
Joined: Oct 2019
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From: Ohio
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Let's play a game shall we?
Above there are four engines, all DI only, all identical other than mileage, two have a separators/catch can and the other two have no PCV whatsoever and the only thing coming into the intake is atmospheric air via the throttle body.
Nothing in the pictures has been cleaned/altered past parts being removed. The separator/catch can in question is a foot long, and 2-5 inches tall with an active control diaphragm and three stages including raw gas cooling initial stage, labyrinth type coarse oil separation, impactor type fine mist separation.
This is far in excess of the performance of aftermarket solutions and has capture down to less than 1 micron vs aftermarket units with no listed performance metrics, no active control, single stage operation, no consideration whatsoever for overall blow-by gas flow or any management system for variable gas volumes, and no regulation to compensate for cold weather.
The game is as follows; what numbers are the catch can/3 stage separator engines, and what are the engines with no PCV at all?
Last edited by Striker223; Jan 10, 2026 at 03:03 AM.
Rookie
Joined: Feb 2025
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Sorry, I do not wish to play your games. Catch cans do catch oil. So yes, they do work. Do they stop all oil from getting through? Of course not. I have one in my IS500 and I pull at least a tablespoon or two out every time I change the oil. Is that enough to make a huge difference? I don't know but yes, it does catch oil.
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From: NW Florida
Lexus Champion
Joined: Oct 2019
Posts: 18,612
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From: Ohio
Sorry, I do not wish to play your games. Catch cans do catch oil. So yes, they do work. Do they stop all oil from getting through? Of course not. I have one in my IS500 and I pull at least a tablespoon or two out every time I change the oil. Is that enough to make a huge difference? I don't know but yes, it does catch oil.
All you are seeing on your IS is water vapor and cold start residue, send out the oil you collect and see what it actually is. It will be a lot of fuel and water plus you have an engine that already uses a fairly good separator.
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Play the game. If it really works then you should easily be able to pick the correct images into two groups.
All you are seeing on your IS is water vapor and cold start residue, send out the oil you collect and see what it actually is. It will be a lot of fuel and water plus you have an engine that already uses a fairly good separator.
All you are seeing on your IS is water vapor and cold start residue, send out the oil you collect and see what it actually is. It will be a lot of fuel and water plus you have an engine that already uses a fairly good separator.
My evidence for them working is direct. I have one and it catches oil that would otherwise be going into my combustion chamber.
Do I need it with dual port injection? Not really but it does catch oil.
Thread Starter
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From: pa
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From: Maryland
Just because manufacturers of vehicles don't use "catch cans" in every application doesn't mean they don't work. Mercedes for instance uses inline oil separators which are in essence catch cans. If they didn't "work" manufacturers wouldn't put them in certain engines.
The million mile lexus is a 1996 LS400 with a 1UZ V8 is fully port injected with no direct injection and operates at quite low compression, doesn't need a catch can or OVS.
The million mile lexus is a 1996 LS400 with a 1UZ V8 is fully port injected with no direct injection and operates at quite low compression, doesn't need a catch can or OVS.
Last edited by SW17LS; Jan 10, 2026 at 02:05 PM.
Thread Starter
Pit Crew
Joined: Mar 2018
Posts: 111
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From: pa
Just because manufacturers of vehicles don't use "catch cans" in every application doesn't mean they don't work. Mercedes for instance uses inline oil separators which are in essence catch cans. If they didn't "work" manufacturers wouldn't put them in certain engines.
The million mile lexus is a 1996 LS400 with a 1UZ V8 is fully port injected with no direct injection and operates at quite low compression, doesn't need a catch can or OVS.
The million mile lexus is a 1996 LS400 with a 1UZ V8 is fully port injected with no direct injection and operates at quite low compression, doesn't need a catch can or OVS.
Pole Position
Joined: Jan 2022
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The oil vapor separator on the 460 doesn't work very well, there is as much oil coating the inside of the intake as there is in the separator itself. I didn't see any pooling in either when I did the V plate leak but it must be burning some vapour/oil and the fuel dilution is keeping the level topped up for some owners.
It's better than having to replace rod bearings every couple of years I suppose.
It's better than having to replace rod bearings every couple of years I suppose.