[chanche]

Bought a 2022 Outlander a week ago and I simply could not resist drilling into the sheet metal almost immediately. I decided to install a catch can to aid in any future intake valve carbon buildup due to the nature of direct injection. Luckily the Outlander has a riser/strut to support the hood that makes its very easy to mount a can. I installed this with about 230 miles on the vehicle, I'll report back on how much it catches after another full tank of fuel. Most of my driving is in town and I keep it under 2k rpm. I drive my vehicles very easy.

I posted a quick write up on network-engineer.org

 

[chanche]

Put about 130-140 miles on the can, popped it out to check. The can was dry in the bottom but that baffle up top that the PCV flow must pass through had a .5-1mm coating of oil starting to build up.

The tank part of the catch can is roughly 3" deep or 76mm. Let assume 60mm is safely full without causing fluid to be pushed up and out from PCV pressure.

60mm / .5 * 135mi (Low end of blow by buildup) = 16200 miles (Your mileage may vary, I don't really go above 2000 rpm in everyday driving)

60mm / 1 * 135mi (High end of blow by buildup) = 8100 miles

High pressure direct injected turbo motors will definitely have much higher blow by which causes the crank case pressure. Poking around on the internet I see a lot of TGDI vehicles that have way higher pressures that the Outlander PR25DD are emptying cans out around 3k miles. Our engine is a very low pressure non turbo so I would expect much less blow by.

While the above math is anecdotal at best it does not appear the the PR25DD suffers from excess blow by or oil in the PCV tract. I will of course drive for another period of time and report back and adjust my estimation.

 

[chanche]

After about 300 miles with the can installed I have 1 small drop of oil that accumulated in the can and a small layer of oil on the baffle. So with this little oil coming through the PVC I would say that the pistons are well sealed and/or even with 12:1 compression the cylinder pressures must be fairly low. Its possible as fuel dilution occurs over more mileage it accelerates the oil/fuel wash vaporization. But more than likely this just means there is very low blow by and a low amount of hot spots in the engine that cause oil vapors to build up. I'll leave this alone for now and report oil catchment before I swap out the OEM engine oil.

 

[chanche]

1000 miles update on the catch can. There was just a tiny amount of gelatinous oil/water/fuel mix in the can. Now this is highly dependent on the motor, how well the pistons seal, rpms and a bunch of other factors. But after 1000 miles with the catch can I would say you probably do not need to add one to this motor. Some engines will have tons of blow-by, it would appear this one is pretty well tight and clean.