BMW Single VANOS: How It Works, How It Fails, How To Take It Apart, & How To Fix It!!

BMW Single VANOS: How It Works, How It Fails, How To Take It Apart, & How To Fix It!!


Hey YouTube how’s it going? In today’s
video I have the BMW E36 VANOS unit taken apart right in front of me so I’m
gonna try to cram as many details as I can about the unit in one video so stick
around. so before I actually dig into the VANOS
unit itself I thought I’d stop by my old friends at Auto Engineering of Lexington
Massachusetts. They are a great group of guys and they’re one of the best around
when it comes to BMW’s, Mercedes, Audi ,and Volkswagens [and Porsches too]. I’ll leave a link in the description below to their website. So I got the VANOS units in this
box right over here and then there’s the sandblaster unit that they’ve kindly let
me use in their shop. So behind me in that room over there is their actual
garage floor where they work on cars… I believe it’s like six or seven bays or
so. So I’ll do a shop tour later in the summer mainly because they’re doing a
bunch of rearranging in the shop, but for now let’s get to the sandblasting. Alright guys so I got both VANOS units
right in front of me right here, one of which is the original one from my actual
car and it’s only partially media blasted. if you guys want to see how I
took apart this VANOS unit from my motor, please check out the video in the
top right corner right here. I basically tear down the motor to the block in a
three part video series (step-by-step details, and then all the hints and
little pieces of advice that I can give you from my experience working on it). So
the reason why I decided to blast this unit completely and take it apart is
mainly because this is just a spare unit that I have laying around in the
garage. I wanted to clean it up the best I can so I can give you guys the most
detail and the clearest representations of the parts of which I’m gonna be
talking about. I want to make it clear that you don’t want a media blast the
entire VANOS unit without taking it apart completely, mainly because one you don’t
want to damage the mating surfaces on the actual unit itself. You basically
want to maintain the smoothest surface possible for all the mating services so
that it makes the best contact with the actual gasket when you reinstall this
unit. So the very most, you could blast the outside so that it has a nice
surface finish in the end because there are parts that are hard to get to
if you’re trying to clean with a brush. The second reason why you don’t want a
media blast these units is to avoid contaminating the bearing surfaces
inside the lubrication system and the actual bearing systems for the piston
assembly inside the VANOS unit. As we all know any sort of particulate
contamination in the lubrication system is just a recipe for
disaster. The best way to clean these parts would probably be taking them
apart completely and throwing them into a hot tank and then afterwards just taking care of little missed spots with like a wire brush or something. With all that being said about the BMW single VANOS system, I’m gonna try my best and explain
how every single little component works with in the VANOS system itself, and then
present all the potential problems you might face as the system ages and how
you can maintain and then fix those issues. So to start off I want to talk about the
actual VANOS housing itself. First, oil is supplied to the VANOS unit from the
oil housing on the side of the motor it comes up a rubber line and into this
bolt right here. Now, this bolt is hollow and has a couple holes in the side to
allow for oil flow from the actual rubber line to go into the actual VANOS
housing. So from there, there’s an electronic solenoid that controls this
actuator spring right here that directs the flow of oil through three different
passages inside the housing itself. I’ve labeled the passages in red sharpie right here just to give you guys an idea of the directions of oil flow in the
VANOS system. So the next components I want to talk about is the piston and
spline gear components right here. Now I’ve taken apart the VANOS unit because of the fact that it’s easier to see how these components interact with each other once all the fasteners and bearings are removed. So as oil is
directed in and out of this VANOS housing, it basically pushes on this
piston right here so that it goes forward and back inside the vanos unit.
so this spline gear is actually connected to this piston, so that as the
piston moves in and out, so does the gear this cap right here basically seals up
the entire lubrication system to maintain the oil pressure as the piston
moves in and out basically isolating it away from the actual gear itself so the
next thing to talk about is how the actual spline gear is connected to the
piston itself you can see that the Torx bolt used right here has a couple
bearings and a couple washers in order to give the initial fastening of the
spline gear to the piston, and then finally to seal everything up, this nut
is used along with this washer and bearing and this thicker washer right
here (which I’ll talk a little bit more about in just a second). So if you take a
closer look at the outer surface of the spline gear you’ll notice that the outer
teeth of the spline gear mate to an outer gear that
rotates along with the intake camshaft, in unison with the exhaust camshaft.
Now those two big gears are controlled by one timing chain. So the inner teeth
of the spline actually mate to the intake camshaft physically because the
gear is of helical design and has slanted teeth that are opposing in different
directions as this gear pushes in-and- out… it actually physically rotates the
intake camshaft independently of those two larger cam gears that are already
timed in unison. BMW came up with the double vanos system later to provide
independent control over the exhaust camshaft advancements as well. So when
the first mechanical symptoms you might experience with your E36 as it gets
older is power and torque loss. so a probable cause of the potential power
losses experienced on an older E36 is from this actual seal around this small
piston inside the VANOS unit. So over time the seal loses it’s elasticity and
becomes brittle and can actually crack the oil that leaks past this seal compromises the functionality of the unit as a whole Now Beisan systems is a great resource for seal repair kits for both single and double vanos. the seals they provide our direct OEM replacements and they’re
actually redesigned for better longevity the next problem experience is called
VANOS rattle. Now if you notice this spline gear can move side-to-side very
slightly or like in a circle… basically that’s called “radial movement”. Now a little bit of radial play is normal. However, what’s not normal is axial play
and by axial play I mean in an out so if you pull slightly up and down on the
shaft or if you wiggle it side-to-side you can physically see that this gear
actually tilts on its own axis. You can clearly see over here that the bearings actually wear down this washer over time and then you can see the same behavior
exhibited onto this washer right here. Now to fix this issue there’s typically
a redesign required for this bearing right here, and Beisa Systems also
provides that with this repair kit right here so the kit actually comes with a
replacement washer that is actually resized to decrease the gaps and all the
wear points inside the system itself. Before you take apart the VANOS unit,
you are gonna need a couple specialty tools, the first of which is a modified 18 millimeter socket. Right here this socket is essentially a
standard 18 millimeter socket but it’s just flattened out and ground down so
that it can mate properly to the lo- profile bolt on the actual piston though
the VANOS unit. The next thing you’re gonna need is an actual advise to clamp
down the actual piston assembly of the VANOS unit. You’re going to need either
rubber inserts from Beisan Systems… you can also just use small pieces of wood
that are flat in order to just safely grip around the piece without applying
too much pressure. The last thing you’re going to need is a pick in order to take
out the old seal and to pick out any sort of thin washers inside the piston
system itself. So moving on from those crazy details about the VANOS unit,
time to take apart this one right here and perform the respective maintenance
procedures from Beisan Systems using their repair kits as well. I’ll leave a
link in the description to those procedures and the parts that I’ve used
in this video. 10mm bolts fasten the piston assembly to the VANOS housing. No gaskets here. The Besian Systems jaw liners grip the unit safely so that you can use a breaker bar on the piston nut. I ended up using an impact to crack the nut loose, and only needed to lightly secure it in the vise with a leather glove. THIS TORX BOLT IS LEFT-HANDED THREAD (REVERSE-THREADED). Pay attention to the order of the bearings and how they are oriented. You only need to lightly clean them. Carefully cut into the two seals around the VANOS piston. Avoid scuffing the channel for the seals. Cool to see how materials change over time. Observe some staining on the piston seal channel. New seals on the left, old seals on the right So now that everything is apart I just
want to quickly acknowledge some specific points and details on their
website in order to install these new *gaskets* correctly and that new washer as
well before installing this ring you can put it in dry. I would actually just put
a little bit of assembly lube around the outside just so that it snugs up inside
the groove over here a lot better in addition to that this outer teflon seal
might need to be soaked in some warm water for about two minutes and dried
before actually trying to stretch it around this gasket right here mainly
because it is a little bit stiffer it’s not really meant to stretch too much
it’s more like an actual ring to a piston than it is to an actual oil
seal for example the next point revolves around this new washer right here now if
you look on their website there’s a very detailed procedure on how to actually
test whether or not this is sized correctly, basically you have to install
this back inside the piston and once it’s installed you actually kind of have
to test for play again and depending on the type of play you still experience
they actually demonstrate a procedure of actually taking this washer putting a
piece of sandpaper and actually sanding it down very very slightly in order to
make all the tolerances correct when refitting this new washer and in the
further demonstrate the differences between the washer I thought I just
measured them up with a basic caliper setup as you can see the measurement
right there for the new washer is as such and I’m actually going to measure
up the old washer right now So you can see that the new washer itself is actually about give or so ten thousandths of an inch thinner than the
stock one so if you work in a machine shop or you have access to a machine
shop… technically you could shave down the old washer itself but it’s just as
cost effective to just purchase this yourself I so everything is put back together and
I did put a little bit of lubrication in the bearings, but if you guys can see
right here the play is pretty much minimal now.
I can’t shake it, I can’t tilt it anymore, and axial play is eliminated here
I’ve been still here that there is side-to-side movement which is normal
but as you can see there is now no more tilting on the axis and as well the
actual actual play itself is gone. There is another company called Dr. VANOS that actually refurbishes VANOS units they’re remanufactured units are pretty
competitively priced and they also feature improvements like modified oil
passageways and in various internal component improvements to give you guys
a VANOS unit that is better than stock, but if you’re confident enough to tackle
one of these projects yourself it’s fairly easy to do, minus the tedious aspects
where you possibly have to take this piston apart again
just to grind down that washer enough so that you have the correct tolerances to
reduce play. So now that everything seems to be okay with the play in the system
and it seems like I don’t have to do much re-tolerancing at all I’m gonna go
ahead and take apart the bolt again so that I torque everything down to the
correct specifications and then proceed with the seals. Lube up the seals with some engine oil or assembly lubricant. Slowly work the seals onto the piston, it is normal for them to be loose Carefully seat the seals into the pistons. Work the piston in and do not let the seal bind on any edges. all right so I got ignition tube right
behind me he’s painting his brake calipers right here you can barely see
them but check out his like though was that so check out the video that I put
up in Ryan corners you guys are interested to see how these brakes came
out so again I don’t know if you guys saw that I pointed it out but don’t
forget to put this cap on before you tighten everything up. Essentially now if you listen carefully there’s no play there but you can still move this radially just to spec, but there’s no play at all and you can still spin it nice and smooth. And if we compare through this old unit right here with no modifications you can clearly see how much of a difference that made. And if you want to test the seal you can clearly hear the piston come in and out
very nicely, very smoothly… as you compare it to this one you can feel that it pretty much just falls in on itself meaning that the seal is compromised All right guys, I hope you guys enjoyed this video of me trying my best to explain
every single detail that I know about for these BMW VANOS units or single
VANOS units rather. If you guys are interested I’ll leave a link in the description for all the resources that I use in order to make this repair in any
of the links that are relevant to this if you’re not looking to service one of
these yourself but rather by an actual refurbish unit from Dr. VANOS for
example. so you guys like the content of this video please hit that “like” button and if you’re new to the channel please subscribe. If I missed any content about
the VANOS units or if there any corrections that you guys would like to
point out please leave it as a comment below. I take any feedback that you guys
give me very seriously and I always want to produce better and better content for
you guys, but regardless I’ll catch you guys in the next video where I’ll be
doing more maintenance procedures on the E36, more mods and then a bunch of work on other cars, so have a nice day guys, bye.