PCV GM 4.2 ATLAS ENGINE 

I hear what you're saying --- but I found that hose to be super easy to remove. It wasn't stuck nor cracked nor stiff. I'm sorry for your trouble, but I'll certainly consider your suggestion. Thanks.

Thank You Joe! Our 2008 Trailblazer 4.2 has been having oil leakage and I've noticed oil below that S shaped hose under the resonator. I did notice that the PCV hose on the left side is hard as a rock. It should be soft and flexible correct?

@@johngligo4049 Super sorry for the late rep[ly ---> but the hose is open stock at most decently goods parts stores. It has to be Green Striped or it isn't approveed just in case you have emission inspections. A smart tester will spot the hose if it doesn't qualify.

I check my system once per month by removing the oil dipstick with the engine idling, sealing the dipstick tube with my thumb for a minute and then notice as I remove my thumb if I hear air being sucked into the dipstick. If I don't hear/feel air, I clean the port!

@@user-cy6gf2pj7y You guys get it --- thanks! Although I don't advocate taking the KV hose off the valve cover - I can see that it works OK - although illegally -- but who's telling?

Best to perform this before oil change. Cleaner and debris will end up in oil pan.

@@davepetrakos475 yep - I ended up doing a couple oil changes - first including a flush. Maybe it was three oil changes? Yeah I had some complications. Just under 300K now.

Not so much as you might think. The reason for dumping the B12 into a hot engine is to get it to boil and fume and that will soften the gunk in the runners. You're not going to be able to get any B12 in the oil pan or on the cams if you follow the instructions where to pour it.

One engines that don't depend on oil pressure to lubricate the moving parts and instead, use flow-control instead - whereas the oil is regulate by amount, not pressure --- using additives in the oil is never a good idea. Notice that I didn't say to pour the whole can into that line --- just a capful or two --- and let it cook before you start it again. This won't allow much liquid to exist in the crankcase zone, so it's not like using a flush-additive. I do not recommend using additives of any kind in the oil. Fuel additives? Knock yourself out --- but leave the oil zones alone.

@@SurferJoe46 OK - I'm just at 297K now - so doubt I'll need to do this maintenance for awhile. You're saying make sure the engine is fully hot first and then pour in a cap and let it sit for awhile before starting up the engine. Thanks. OK I did use a pint of boron nitride - micron size - it's less than .5 micron. I get it from AET systems - but it's made in Germany by Wagner. I added that to the oil.

Gosh ---> there are numerous reasons why this can happen - and I am on a great site that specializes on these engines and their driveability problems .... www.trailvoy.com/ ---> c'mon over .............

OK --- very late reading your post --- but there should NEVER be any pressure in that hose --- never can it blow things out of it even if the engine's running. It is a vacuum hose and as such, it sucks for the lack of a simpler word. I think you're in the wrong hose or something else is really screwed up.

You already have very low-to-no flow now ... why put another restriction in the circuit? Oil catch cans are chasing a symptom, not a repair. Depending on the can, you still have no way of removing condensate ... it'll just keep creating more water and oil emulsion in the pan until it blows oil out the dipstick tube. Catch can = very bad idea.

A new - vibrant, flexible and rubbery hose will go on --- just make sure it has the Gates Brand, Green Stripe.

@@SurferJoe46 thks Joe - I often think of you when I read my average MPG - you said you had 1000 lbs of tools and you get 23 mpg? At what speed? How flat? what temperature? Also isn't your gear ratio the big factor? Here in northern midwest - I notice the MPG is down when it's around say 15 degrees - or maybe that was because it was so windy!! Yeah. Anyway I did put on that new Gates PVC hose - when I also did a cleaning of the oil pan with some acetone flush - and I did some more acetone flush via the PCV... and then I put on an external OEM Magnefine from Australia - the Remans transmission runs better now. I also put on a new catalytic converter - or the muffler shop did - since that Berryman's engine flush - or also the acetone - seemed too harsh on the OEM catalytic converter that was 20 years old. Now I get this nice deep rumble.

@@voidisyinyangvoidisyinyang885 Higher fuel use can be caused by cold temperatures --- but not for long once the engine gets to about 200° when the thermostat should open. If you don't get hot by a couple of miles, I'd suggest that your thermostat is slow or prematurely opening and keeping the engine too cold. That will burn more fuel - and although it's incorrect, the ECM can only react to the inputs it gets from various sensors.

@@SurferJoe46 yes thanks for pointing that out. I can get 23 mpg by going 55 mph. Not sure what speed you meant by highway. I live in the northern midwest - in fact in some of the coldest temps in the lower 48 - so definitely in the winter the mpg goes down a lot. It can take 20 minutes for the oil to heat up. The engine temp is not the same as the oil heated up so I switched to 100% full synthetic oil - that helps for sure. I also now add boron nitride - the micron level at .15 size as a lubricant - it's sold from Wagner out of Germany under the company AES or advanced engineering systems out of Wisconsin. Air-tec is the brand name. I noticed the engine is super quiet after adding boron nitride - it fills in the pores in the cylinders and valves. It lasts I think 50K miles or so. So I can add that about once a year. I have not changed into the air filter I have that is a dry filter that is reuseable - this is to increase the oxygen level to the engine. I guess I should do that. I'm just about at 300K now - around 294K.

There is no PCV "valve" in this system.

Yuppers --- pretty much so.

Any oily deposits in the sound chamber is/are/am bad. The OBD2 won't "see" the PCV system failure or if it's running well --- or at all! Therefor, you won't get a code for it if it fails -- which it is doing since it came off the assembly line. It just takes time to show up as an oily discharge and then the failure to control same.

Did it work? My 2004 Gmc envoy just started getting the oil milk in the intake . I was thinking this or pcv purge device??

.... and just where would his PCV Purge device go? What's a PCV Purge Device anyway?

How did it turn out for you?

@@SurferJoe46 Thanks Joe - not sure if I mentioned that last Fall I finally just put in the NEW PVC hose - replaced it on that port - on the intake valve cover there. Seems to be working just fine! I had to replace my ignition coils and spark plugs - I was messing with some engine clean out formulas. I ended getting the catalytic converter replaced since I put acetone in the engine also - a new one only cost $200 and then the muffler shop welded it one for me (they got double pay from the old cat I suppose since I never asked about that.) I had used acetone if I recall - oh yeah that's what I had first poured into that PCV hose also. haha. Anyway engine has been working fine. I'm just about at 275K. The new cat has a low rumble to it that sounds very cool but the MPG is not as good. I think I lost a mile on MPG from the new cat! Yeah I had to make sure that PVC hose - the old PCV hose was not clogged - and so I just put in the new one. I was surprised at how easily the old one came off but it was a bit brittle. I think what happened is I put in some "snake oil" to clean the engine out - and I got a misfire in cylinder six after driving around for a bit to work in the engine flush. I think I accidentally had too much oil with the engine flush and I got air bubbles that had caused the misfire in cylinder six. So then I freaked out thinking that the cylinder had gone bad - after I replaced the coil and spark plug and I still got a misfire! That spark plug six is hard to reach under the firewall and I had accidentally cracked the new spark plug because the spark plug wrench did not fit on that brand of AC-Delco. So the next new spark plug I put in I was extra careful not to over torque it. The mechanic I used for welding on a chassis repair kit I had designed - for along where the muffler and cat is - the rust builds up there from the heat. So I had a hole right in the inside wall of the chassis over that triangle brace that connects to the transmission cross brace support. found this engineer in Iowa that does custom repair kits with his laser welding CAD system. I just had a new Reman Trans put in and they made me get a new cross brace support - I drove out to this salvage an hour or two hours away to pick it up in time for the new Reman Trans install. haha. So the transmission mechanic said NOTHING about the hole appearing in the chassis on the inside wall. And when the mechanic welder put in the repair piece - first he told me that the Misfire was INTERMITTENT and so it definitely was NOT the cylinder gone bad! What a big relief that was to hear! And also it was not a valve with bad seating since it was Intermittent!! Wow I was sure I had overheated the engine from too much snake oil causing that misfire originally. So that motivated me to discover I had cracked the porcelain on the new spark plug. I have NEVER replaced spark plugs before and it was at that moment that I got the gumption to finally just REPLACE that pvc hose since I had the new one sitting around. hahaha. So that was my saga to keep the TB going. I'll change the oil again in 500 miles. I changed the oil myself for the first time also since I had to do an engine flush to get out that Liquid Moly stuff. THAT's what CAUSED the misfire!! I remember now - I combined the Moly engine treatment with some other stuff - I think it was inert so I figured it was ok. Nano ceramic boron-nitride!! It's from Wagner in Germany marketed in the US as Air-Tec. So I had about a half a quart extra oil that was from the snake oil supplements - a quarter of a quart of the Liquid Moly crap. That stuff is MAGNETIC metal and it messed up the ignition coil. It literally got SUCKED UP into the ignition coil!! That's what caused the misfire. I did a video about it. haha. I suppose that Liquid Moly stuff is ok as an engine flush if you don't add it with anything else - since that half quart extra - if it is NORMAL oil it is supposed to be ok. I know the V8 engine drivers of the TB will use an extra half quart since the oil pickup is in the front of the pan and so a quick torque acceleration JERK 3rd derivative will cause lack of oil in the pickup. So that's why I first figured an extra half quart of engine flush supplements - since the boron nitride is supposed to work into the engine... Oh well. I actually have some more boron nitride that I want to add again when I do the oil change next - I'll just leave out a quarter of a quart since now I'm paranoid. haha. It should be fine though with an extra quarter quart of boron nitride since it's inert. They say that stuff does not clog the oil filter since it's Nano size but then they"qualify" that if your oil is dirty then it can clog. haha. So only add it when there is new oil at the oil change. Then it should work into the crank case, etc. to fill in the holes from metal wear or grit, etc. Actually when I did the engine flush I actually got a spray straw sucked into the oil pan!! I could not get it out - it just vanished into the oil pan. The welder mechanic said not to worry about it. haha. Hilarious. I sprayed acetone into the oil pan when it was empty - and then I used MMO to flush out that acetone and I let it drain over night. Then I added more oil back in. And THEN I had the welder-mechanic change the oil again just to make sure I got that acetone out of the engine. hahaha. I'm sure it would have burned off if there was any left since I had used a LOT of acetone at first to clear out that Liquid Moly crap. But the muffler welder said - NOW you're not just going to destroy this NEW cat are you? So I wanted to make sure I didn't have any acetone left it. Whew!

Holy shit^^^^^

@@joshuakeith8710 I'm now at 282K and the engine seems great - have 5K on full synthetic oil. Should probably change it soon since I've been hauling some weight long distance. I'm a big fan of epoxy spray paint now - that appliance stuff - only one kind sold at Menards! Best paint to keep the rust off the vehicle. That porcelain finish - kind of strange there's only one epoxy spray paint of so many kinds of spray paint at Menards.

Right! There is no "valve" at all.

It isn't a good idea to spray anything into that nipple under the "S hose" --- as it drips directly onto the camshaft and you don't want to clean the lubricating oil off of THAT!

@@SurferJoe46 oops - I drove it around and it survived so far. Should I take it for another spin to burn off that stuff so it doesn't soak in?

I'll go drive it again to evaporate off that acetone. Thanks. Says otherwise it will rust overnight. oops.

@@SurferJoe46 OK the engine seems to have survived - I added Lucas and then got an oil change. Then added more Lucas. Then got another oil change!! Now my MPG has gone up better than the Factory Rating and I have 267K miles on the engine! So I think I gained at least one MPG if not more from that accidental acetone cleaning. NOW - that PCV hose in the negative vacuum CV side - it's too brittle and inaccessible to remove. So I would have to remove the whole intake manifold which is a huge job that is beyond my capability. So I didn't feel much of a "negative pressure" when I held my hand over the oil - but that' when I had Lucas in that was clogging up my VVT. So I'll test it again. If I don't feel much negative pressure then I'll take off the air box to look for oil blow by. The oil fill tube is clean as is the dip stick. The oil coming out of the engine is clean. I get oil changes every 3K miles almost always - just went over a couple times. Also I do long road trips to "clean out" the engine - like 200 miles - routinely. So maybe that Acetone also cleaned out the PCV system a bit also one would hope.

I think small marbles can pass through it --- you DO mean the CV-side --- right?

@@SurferJoe46 I replaced it ,it's call pcv value tube, it's hook up to the air box, $16 at O'Reilly dorman ,life time warranty

Butting up to nothing is not the way it was designed. FWIW ---> you can JB Weld another nipple into the box if you like --- and I think you should because it is supposed to be a sealed system, not just a hose pushing onto a place where a hole happens to be.

@@SurferJoe46 thank you so much I kind of figured the piece was missing

Well, Mohammad --- this is gonna be fun! 1. Blown-out valve cover gasket --- THE FIRST PROBLEM! 2. Spark plug(s) and coil(s) covered in oil 3. Mysterious oil leaks on the frame and the ground, which are really not so mysterious. 4. The insidious P0300 code --- or any other individual cylinders (#s 1-6) reporting they are misfiring can have you chasing your tail 5. P0325/P0327, etc., might appear IF the Knock Sensor gets wet with oil. The valve cover gasket is designed to keep oil in the cam galley -- and if the KV hose is plugged up then the pressures can build too high for the valve cover to contain. The most immediate result is that the spark plug recesses fill with oil and some people think the oil is from the combustion chamber. IT IS NOT. When they remove the plug and the oil runs into the threads and the top of the piston, they think the cylinder is full of oil and the plug is fouled from it. They are wrong.

@@SurferJoe46 I have oil in the spark plug recesses. Does this indicate I need a new valve cover? DO you have a video on how to replace that? Thanks, great videos BTW!

@@trkonkal Oil leaks at the valve cover can be evidence from pressure in the crankcase .... caused by an improperly operating PCV system because that blowby will find a path to escape ... usually the valve cover gasket. Oil will collect in the sparkplug wells and damage the coils and rubber parts on the plug boots. Just changing the gasket will not cure the probllem with pressure in the crankcase. You have to go through the process of cleaning the ports that are full of gunk and crust from cooked oil byproducts at the same time. I don't have a video on replacing the valve cover gasket .... there are a few on YT though.

@SurferJoe46 Thanks Joe, your speedy reply, advice, and videos are very appreciated!

There is a vacuum booster line --- and there's a CV hose too. Look closer and see for yourself --- and yes --- there is NO PCV "valve" --- that's well established already.

The top of the hose goes to the plenum and the bottom goes to the intake runners. You don't need as much clearance as you think. You can destroy the old hose - but have the new hose ready. The new hose is available in bulk --- you do NOT have to buy an exact replica with a GM part number on it. Once you get the clamps off, cut the hose off if it won't slide off easily. Then you can replace it with a new piece. It is really simple. In most cases, the new hose won't need clamps --- it's not going to leak. Use: BERRYMAN'S B-12 Chemtool. I have no idea what "Barrington" is.

Maybe I should say that you can just cut this hose off and replace it with a new piece of bulk hose from a parts store. You do NOT need a factory formed hose --- it's almost perfectly straight - so that idea should be off the table. Cut the old one off if it resists at all! Hose clamps, although pretty - are not even needed to hold it in place --- there's no pressure in it so it doesn't need to be clamped on.

Then get a sharp box cutter type knife and carve it away until it slides off. It IS replaceable from a parts house as a bulk Gates Green Stripe Emissions Hose. Remember that Emission hoses are sold in 32nds of an inch inside dimensions. It should look like 19/32: or 21/32" or something like that. Be sure to use the liquid version not the spray unless you want to have a lot of empty cans around.

.... and ignore my oddball user name -- it's me.

Mohammad ... I do not understand your language syntax. Please ask me the question so I can understand you.

That hose has nothing to do with PCV system that's your vacuum for your brake booster which most vehicles have yes you can put cleaner in there I would suggest you just using seafoam and spraying it in there while it's running to clean it back to the PCV system it needs a PCV valve in it which there is none I am thinking about installing one of mine

@@markthrush2139 You are not gonna like this --- but you are wrong on every level. 1. I don't like people who like to be ignorant and say ignorant things as spiritual epiphanies. 2. I don't like people trying to correct me when they have ZERO idea of what they are speaking. YOU fit one or both of those categories. Go away!