Learn how IMPORTANT the PCV Valve is and why you should test it.

hello folks welcome back i hope you stick around  what are we doing today i'm going to show you this   trick that's amazing you're going to want to rush  to your hood open it up and do this it's so simple   it's so accurate it's so important it's hard to  believe how a piece of paper is going to test an   advanced emission control device that's so  important to preventing all kinds of problems   all you need is a piece of paper now this paper is  too big we're going to have to trim it up a little   bit you're going to want a piece of paper that's  going to be about this big let me finish it off   i'm going to take this piece of paper right here  and it's unbelievable what you can do with this   i don't know if everybody knows this but this is  amazing this is a positive crankcase ventilation   system pressure analyzer what the hell is that  it doesn't matter here's what we're going to do   it's easy the hardest part is getting you to  open the hood i swear the hardest part of this   is getting you to open the hood now some of you  are hood people and they'll have no problem i hope   you learned something from this before i start the  engine because it's going to get a little noisy   i'm going to tell you what we're gonna do what  we're going to do well let me put my paper down   because i need both my hands we're going to find  the dipstick as in the engine oil dipstick on this   particular vehicle it's here i'm going to take the  dipstick out i'll wipe it off a little bit and put   it in a safe place i'm going to put the dipstick  in a safe place i'm going to take this analyzer   where is it there it is i'm going to take this  analyzer paper and i'm going to test it to see   if it fits over the tube this is the dip stick to  where the dipstick goes this looks like a good fit   you want one that's pretty close the right size  too small we don't want it to get pulled in too   big we don't want it to get pulled out you're  going to wind up with a piece of paper like this   sometimes we have to put a little extension  and i'm going to show you how to do this on two   different vehicles what we're going  to do we're going to find the dipstick   we're going to take it out wipe it down put it  in a safe place we're going to practice putting   this little piece of paper over the tube and then  what we're going to start the engine i'm going to   come over i have to tell you everything ahead of  time so you'll know what's going to happen because   the engine gets a little noisy with the engine  idling i'm going to take this piece of paper   and i'm going to put it on that too and guess  what that paper should do guess it should stick   there should be a slight subtle vacuum on  this okay let's do it let me start the engine with the engine running idle i take the piece  of paper i put it on the tube and it should stay   there this is just the beginning of the  beginning if i put my finger on that   you cannot feel the suction the paper  is sticking because there is suction   the suction is so subtle you cannot feel  it i'm about to show you this is a good   this is what you want you want that paper to stick  if that paper doesn't stick there's something   wrong and then there's another what i'm going  to do next is i'm going to unplug the pcb valve   and watch what happens to the paper the paper  is there only because of this very subtle vacuum   it's called crankcase pressure and you want and  i will elaborate so much that you will want to   check your crank case pressure this is way  more than just an emission device come on in   okay there's the paper over here take a look i've  got the hose that goes to my pcb valve all right   keep your eyes on the paper can you see the paper  because what i'm going to do i'm going to disable   the pcd system and guess what happens with the  paper when i take off the hose the paper turn the   paper falls off sometimes the engine will stall  and that's okay but we had a very good result   with the engine idling and the pcv system  all functioning the paper was able to stick   this is so important your paper should stick  but there's some exceptions to that now we're   talking about the pcv system the pcd system is way  more than just an emission control device this is   such a simple test it's an accurate test it's an  important test yes in the early 60s the pcb system   came out today most vehicles still have this  now the pcv system does more than save the world   yes it's an emission control device but it does  two other major important things and a lot of   people don't know about it what am i talking about  i'm talking about cleaning the oil the pcb system   is the main valve that helps to keep your engine  oil clean i'm going to elaborate on this toward   the end of the video i'm going to show you plenty  of examples that will help you understand the pcv   system is good for three things the first thing  is good for save the world there's nothing wrong   with that and the worst this world needs saving  everything that we can do the pcb system the paper   needs to stick if your paper doesn't stick there's  something wrong the second thing it does that's   the main control valve that helps to keep your  engine oil clean who wants clean engine oil i do   the third most important thing and they're all  equal the third most important thing it helps to   prevent oil leaks i'm going to elaborate i'm  going to explain if the paper doesn't stick   that means that you have positive crankcase  pressure you don't want that if you have positive   crankcase pressure you're going to blow your oil  seals your your gaskets are going to start leaking   so for many reasons we want to be able to do this  test but what i'm going to do is explain to you   some more details a good pcd system should  stick the paper but four cylinder engines   struggle to do that your eight cylinder your  six cylinder doesn't matter if it's in line or b   with sixes and eights a good pcd system should  stick the paper but four cylinder engines   struggle to do that your eight cylinder your six  cylinder it doesn't matter if it's in line or v   sixes and eights should stick the paper  i've noticed on four cylinders they struggle   let me show you what's going on here we're  gonna have to do a couple of modifications   because the our dipstick too is a little harder  to get to and i'm going to have to put a little   longer piece of paper because i'm going to tell  you ahead of time what's going to happen because   that's how it works i'm going to tell you ahead  of time what to expect on a four-cylinder engine   with the engine idling same thing the dipstick  removed same thing i'm not expecting the paper   to stick and you should be wondering well why the  engine is too small to create enough vacuum anyway   here's what i'm going to do i'm going to  start the engine i'm going to come on out   i'm going to have to leave the strip  because i'm not expecting it to stick   and you're going to see what i call flutter  is going to pull and push and pull and push   and pull and push the paper will never stick  when i begin to elaborate on the pressure that   we're measuring you might question yourself  do i really want that four-cylinder engine   i'm not saying nothing bad but let me show  you a particular the eight cylinders and   the six cylinders should have no problem  sticking that paper let me start the engine   sometimes you have to turn the ac off because the  electric fans are gonna fight you i had to turn   the ac fan off because they won't even give me a  chance so with the ac off when the fans are off   i'm gonna take that paper and i'm going to see  what i have the paper is fluttering fluttering   means it goes up and down i'm not gonna try to  keep it there because i know it's not gonna stick   i know that four cylinders are somewhat  limited on their negative crankcase pressure   this is what i want you to understand it's  so important that that paper stick and i'm   going to justify my importance and explaining why  it's so important to do that on a four-cylinder   engine it has to be a big four-cylinder engine  i've tested brand new four-cylinder engines   and they don't have the ability to create  enough vacuum to put the crankcase under   vacuuming that's what we want because i  promise i'm going to explain to you on the   eight cylinders the six cylinders it should stick  and i'll explain what happens when they don't the pcv valve is part of the pcv system before  i explain the operation of the pcv system then   we begin with combustion this is combustion this  is what propels the vehicle down the road we are   under the power stroke but over here this and this  it's called blow by blow by is probably the most   untechnical term that i've ever heard  can't they come up with something better   blow by are gases that are escaping past the rings  in the cylinder because the pressure is so high   the pressure in the combustion can be anywhere  from 500 psi at idle to four times that much   during heavy acceleration there's going to be some  blow by gases now this illustration says if it's   escaping exhaust gases you mean like exhaust gases  yes exhaust gases close it close enough combustion   gases exhaust gases let me tell you about exhaust  gases there's five of them there's carbon monoxide   there's hydrocarbon there's nitrogen oxide  these are all poisons they're bad for the people   they're bad for the world and and they're bad  for your engine oil your engine oil goes in   so clean but comes out so dirty have you ever  wondered why the engine oil gets dirty it's not   because of dirt it's because of exhaust exhaust  gas is in the blow by or headed right towards your   oil pan now the other two gases in the exact  and the exhaust is carbon dioxide and oxygen   oxygen is harmless and we're not sure about the  carbon dioxide here the yellow arrows is pointing   to an oil pan and guess what's inside the oil pan  your engine oil and yes who wants exhaust gases in   their engine oil i don't look at this illustration  the blue lines look so pretty but it's not   this is where the poisons are the three poisons  that are bad for people the world and your oil   they're all over the crankcase in fact  they're down in the oil let's get rid of it   a pcv valve with help from a large vacuum  hose is going to draw the poisons back   into the engine here's how it works there's  the poison the pcd valve will draw under vacuum   these poisons it'll allow the three poisons to  re-enter through the intake manifold will then   send them to the combustion chamber where we  run it through again and clean it up it works   great the pcb system is one of the oldest emission  control control devices around it works great   until it gets dirty the hoses get dirty the  valves get dirty the hoses get dirty this is   poison mixed with a little bit of engine oil dirty  engine oil you saw the video i'm not making it up   if the paper does not stick your pcb system  needs attention if the paper does not stick   you are polluting the earth because your pcv  system is not working correctly your engine   oil is getting dirtier faster and you haven't  heard it all and you're asking for oil leaks   what does the pcv system and oil leaks have in  common there's three kinds of crankcase pressure   when the paper sticks that's what you want  that's called negative crankcase pressure   that is very desirable that's what you want you  want the paper to stick when the paper sticks   most engine oil seals whether they be the rear  main seal the front seal the camshaft seal   some kind of auxiliary balance shaft seal  whatever they are these seals are not under   pressure in fact when the pcb system is working  correctly they're under a very slight vacuum   there may be some seals that are exposed  to direct oil pressure like the oil filter   the oil filter is exposed to direct oil  pressure and can easily be over 60 psi   these seals they're close to the pressure  but are not exposed directly to the pressure   they should be exposed to negative pressure  which is called vacuum inches of mercury   most of your gaskets and seals are  exposed to crankcase pressure which   you want negative some of the head gaskets do  have direct oil pressure they are some there   most of the gaskets and seals of the engine are  exposed to crankcase pressure not oil pressure   what were the three kinds negative that's what you  want that is desirable you have positive crankcase   pressure you don't want that something is wrong  and then you have the four-cylinder flutter   makes you wonder about those four-cylinder engines  the paper sticks you're helping to clean to keep   the earth clean you're helping to keep your oil  clean and you're helping to prevent oil leaks   if the paper does not stick yes your emission  device is polluting the earth you're also   polluting the oil and you're asking for oil  leaks i would not own the four cylinder engine   just because i know it struggles to create  negative crankcase pressure they have a tendency   to leak oil because of the positive crankcase  pressures they don't work so well did anybody   notice my special patch that i'm wearing today  this one right in here this is the one i normally   wear i normally wear the legitimate one the ase  patch some of you saw this this is one of the   oldest most prestigious certifications i've been  certified seems like forever one of my students   so clever so witty he modified my patch i'll show  you a picture of it it was about 20 years ago   i had i had an image i had my patch and through  the wizardry of computers and electronics he   modified my patch i must have pissed him off that  day again right i have expectation for my students   some of the students think i'm an ass it's  mostly the ones that don't want to perform now   the other semester they gave me another special  patch you know they gave me the half ass patch   now being a half ass i guess is better than  being the whole ass or is it the other way around   thank you folks thank you for sticking around i  hope you enjoyed the video i hope you go check   your positive crankcase pressure i hope you keep  coming back and you know what i really really want   i would appreciate it so much sure just give me a  thumbs up or give me a notice but what i want if   possible is a subscription i'm going to continue  providing this so i'm going to show you explain

Channel: The Old Mecanico Show

Views: 664,859

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Id: l3ppNvofPHI

Length: 19min 22sec (1162 seconds)

Published: Mon Jul 27 2020