hello everyone and welcome in this video
we're gonna be talking about why oil
catch cans are a great idea especially
for direct injection engines now this
video is brought to you by RetailMeNot I
will talk about that more at the end of
the video but know that there is a
relevant link in the video description
and in this video we're gonna be
focusing on four main topics so the
first one being a quick overview of how
these systems work how oil catch cans
work the second one will be looking at
some scientific research to see what
data-driven answers we can get behind
whether or not these devices are
effective the third thing we'll be
looking at a real-world example so
looking at an oil catch cans use on a
Volkswagen and then finally we'll end
with looking at different priced options
so I have a twenty five dollar oil catch
gain right here $100 oil catch can right
here and then this one is two hundred
thirty dollars so we're going to look at
different priced options and see if it's
actually logical to spend more money or
whether or not you know you can get away
with something that costs a bit less so
looking at my s2000 engine here it makes
it really easy to understand how these
oil catch cans work and so here we have
the valve cover on top of my engine and
you can see this hose leading from the
valve cover over to the intake manifold
now this is the positive crankcase
ventilation system and so what it does
when you have combustion strokes you're
gonna have that high pressure on top of
the piston and some of that high
pressure called blow-by can come past
that piston and it'll pressurize your
crankcase the area underneath the piston
and so you need that pressure to be able
to escape and that's why they have these
positive crankcase ventilation systems
so it allows that high pressure to
travel from your crankcase over to your
intake manifold now in doing so any oil
mist that's turning around within your
engine as well as contaminants that have
passed by your Pistons from blow-by can
then enter back into your intake
manifold through this positive crankcase
ventilation system and that means those
contaminants can then hit your intake
valves the oil can hit those intake
valves and you can start having deposits
build up on your intake valves so the
idea behind an oil catch can is that you
reroute this hose so you take one end of
the hose and you send it to the inlet of
this oil catch-can and then within the
oil catch hand you're going to have a
filter as well as this baffle here in
school
going to separate out that oil from the
air and so you'll have the oil trapped
at the bottom of this catch-can and
you'll allow that air to travel then
you'll have a hose routed out back to
the intake manifold so you don't allow
those contaminants from reaching your
intake valves and thus you help prevent
deposits from forming on the intake
valves now with port fuel injection like
on my ass mm this isn't that big of a
deal because the port injectors actually
spray fuel which goes over these intake
valves and helps to keep them clean with
direct injection engines you don't have
that fuel cleaning the valves and thus
they're more likely to have deposits
form moving on what does science tell us
about positive crankcase ventilation
systems and how they affect intake valve
deposits with direct injection engines
so I found a very cool study published
in Society of Automotive Engineers and
they were looking at a 2008 Pontiac
Solstice with eight hundred thousand
kilometers on the clock so very
impressive that a solstice made it that
far the reason they chose to use one
with such high mileage is that it
accelerates the deposit forming process
and so as a result they're able to run
these tests more quickly and see what
would happen what scenarios caused
deposits what scenarios do not so the
Pontiac Solstice used for this
experiment has a 2-liter turbocharged
gasoline direct injection engine it
produces about 255 horsepower and it's
doing so with about 20 pounds of boost
so the experiment the study performed
was to take the Solstice engine and to
put it on a repetitive Drive cycle that
would last for 16,000 kilometers now at
the end of those 16,000 kilometers they
would replace the spark plug the fuel
injectors and the intake valves for the
next test and they would weigh the
weight of the intake valve before and
after those 16 thousand kilometers to
see how much valve deposits were formed
how much weight gain was formed on that
intake valve during those 16,000
kilometers now what they found was
pretty fascinating and the set up is
actually a lot like - 2000 engine here
where there are two valves per cylinder
and then there are four intake runners
and then that positive crankcase
ventilation system comes here to the
center of the intake manifold and what
they found in this study with the
solstice engine is that valves 2 4 5 and
had the greatest amount of deposits
formed and so why might that be well if
you see this positive crankcase
ventilation system here it's routed in
and then depending on whichever cylinder
is on the intake stroke that's where the
air is going to be flowing and so the
side that's closest to the positive
crankcase ventilation system got the
majority of the deposits and that's
because those heavier elements those oil
droplets of course go to the closer
intake valve they don't travel further
now those heavier elements don't travel
as far and they go to the nearest that
path of least resistance the quickest
route and they just go straight to that
first intake valve so on this side
that's valves 2 & 4 and then on this
side that's going to be those left
valves valves 5 & 7 so for the first
part of this experiment they found that
yes they will have carbon deposits
forming on the intake valves so for the
second part of the experiment they're
going to run the exact same cycle those
16 thousand kilometers but now they're
gonna reroute that positive crankcase
ventilation system away from the intake
manifold so the intake manifold is then
going to be plugged and you're not going
to have any of those contaminants
traveling from the PCV system to the
intake manifold and what did they find
well crazy enough the intake deposits
forming on valves 2 4 5 & 7 was
dramatically less than when they did
have the PCV system routing to the
intake manifold so what does this prove
well if you can reroute those fumes and
effectively capture that oil like in an
oil catch can then you can dramatically
improve the amount of integral deposits
that are going to form on your engine so
what might we see happen in the real
world
well all of my cars are either port
injected or they run on like electrons
or something so I reached out to my good
friend Charles Hummel mechanic who is a
Volkswagen enthusiast he has spent quite
a bit of time with quite a few direct
injection Volkswagen engines and he said
some experiences using oil catch cans in
direct injection Volkswagens so we're
gonna send it over to Charles to learn
more about that what's up everybody's
Charles from humble mechanic calm today
I'm gonna give you guys some of my
experiences dealing with catch cans and
VW direct injection engines like I got
sitting right here for the most part all
VW gas engines at least in the modern
day are too
Injection which means we're putting fuel
right into the cylinder and while that's
awesome and gives us a ton of
flexibility with fuel timing it does
have a pretty significant drawback and
that is carbon deposits building up on
the backs of the intake valves this
carbon buildup on the back of the intake
valves can cause things like cold start
misfires pour fuel economy and even a
reduction in power something that a lot
of people have done is install a catch
can to reduce the amount of carbon
buildup on the intake valves this catch
can is from Black Forest Industries
retails anywhere from 350 to about 550
bucks depending on how you want to trick
it out and I installed this one on my
2015 volkswagen tiguan i first drained
this catch can at about 3,000 miles and
as you can see there was a lot of junk
that came out of the catch can it looks
like a mixture of oil fuel and water so
Wow I don't think a catch can is going
to solve all of the direct injection
carbon buildup problems I really think
the less of this junk running through
our engine the better off we're going to
be and on vehicles that are modified
this becomes even more important alright
everybody thank you so much Jason I'm
going to throw it on back to you thank
you so much Charles so now let's talk
about how much perhaps should one spend
on an oil catch can so I've got three
different ones here about 25 dollars a
little over a hundred dollars and over
two hundred dollars here so what
features do these have and what price
range makes sense for you so honestly as
far as build quality I've been impressed
with all three of these I don't think
any of them really are that bad of a
decision
so with this cheaper one here this
$25.00 one two the features that I do
like I does actually come with a
dipstick so you can check the level of
contaminants and oil that you've caught
within the catch can you don't actually
have to unscrew it every time so you can
check on that I think that's nice and it
does have a very simple baffling system
to help prevent that oil from going back
up and then traveling over to your
intake it is fairly small and there is
not a drain port on it
so this hundred dollar one here quite
small very nice build quality to it it
does have a bronze filter which is nice
so this one doesn't actually have a
filter on it it just has some baffling
so this has baffling as well as a low
micron bronze filter on it to help
prevent that oil and those contaminants
from going back into your intake the
only thing about it is that it's pretty
small
but nice that it does have that drain
port down at the bottom and then the big
guy over here this is probably the
nicest one I could find when I was
looking around on it different ones
online so it does have a nice bronze
filter right here it does have the
baffling system like the hundred dollar
one also has the drain port there at the
bottom and it's a good size to it so you
know you're not gonna have to dump it
out as frequently you're able to hold
quite a bit more in this of course just
looking at these size-wise
so nice if you have the space within
your engine compartment to stick this
guy it'd be good you won't have to check
it quite as frequently but honestly
overall none of these really look like
that bad of an option the big advantage
to these more expensive ones being that
bronze filter whereas this doesn't have
a filter so you're really relying on
that oil and air to cool and separate
out as well as just the longer
passageway that that oil has to travel
and hopefully you catch it rather than
relying on a filter to make sure it
doesn't go into the engine so you do get
a little bit more if you pay a bit more
but honestly all of these seem like a
butter system than doing nothing at all
now again this video is part of a series
where I have teamed up with RetailMeNot
which has a free browser extension
called RetailMeNot genie that's designed
to compile all the coupon codes out
there so that when you purchase a
product online you get the best deal in
this case we've created a unique
promotion just for you viewers so if you
click the link in the video description
you will get $10 off any purchase made
on auto anything comm over $50 they have
all kinds of products and performance
parts it doesn't have to be an oil catch
can that you use the discount on and
this offer can be combined with any
other deals that they're offering as
well
which you can easily get by downloading
the RetailMeNot genie browser extension
personally I've had a great experience
using auto anything comm because if you
ever use their chat feature they have
always helped me beat the lowest price I
can find out there simply by saying hey
I found it for cheaper on this website
and then they'll match it or beat it and
then you can take an additional $10 off
using the link in the video description
again a big thanks to RetailMeNot for
hooking up all the viewers with $10 off
I hope you're able to take advantage of
it and thank you all so much for
watching if you have any questions or
comments of course feel free to leave
them below