TOPIC: Modification of the PCV System

Here's an old video on the PCV System...

Notice that the system is actually an open loop, supply air delivered to the system from the intake air stream, but before the throttle plate. Once the vacuum is restored by applying a vacuum cap (or plugging the valve itself in certain cases) then the blow-by is directed to go OUT the breather hose.

It is still delivered to the intake air stream to meet EPA requirements, and given the minimal (<.01%) of the volume of vapors passing through the engine, the 10mm or larger hose is more than sufficient to vent all successfully, and at below atmospheric pressure, so you get a good vent action!

CRITICAL NOTE!!!

Ever hear of getting water into your oil?

ANYTHING good?

Then you should ask yourself one question. "If getting WATER into your oil is such a BAD thing, WHY do automotive manufacturers induce water into your crankcase?"

Because that is EXACTLY what the PCV system DOES, and in the form of a little thing called 'Humidity'. The moisture in the air (humidity, rain and snow) is drawn into the system through the breather hose. As the crankshaft spins at about 1600-1700 RPM's on average, it's throwing oil around down there like a STORM.

As the moist, cool air passes through the rain storm of HOT oil droplets, the cooler, moist water-rich air bonds with the oil, and drops into the crankcase. This pollutes the oil starting IMMEDIATELY.

It is my belief this system is responsible for about 80% of engine wear.

So, tell ALL YOUR FRIENDS to stop KILLING their oil and PLUG THIS SYSTEM ASAP!!!!

Ron

I have question, on the 3.7L Honda/Acura motor the pcv valve is not connected to a hose. I did cap off the intake and valve cover. PLease take look at picture if I did correctly or if I need to something additional. Thanks
Sorry, glitch in the system. Ron

Since we are talking about the PCV system here, I thought I'd post re: the PCV re-route I just did on my new ride, an '02 Subaru Outback. The Outback has 139K on the odometer and it's the EJ25 4cyl 5 speed manual AWD version. Since I got it last month, it's had an oil change, new air filter, and was just given the RVS engine treatment. I did a 50 mile "Orange Test" MPG run recently and saw just under 30 MPG hiway.

The PCV re-route was blissfully easy on this engine. Since I didn't know where the PCV valve was I just searched on Youtube, and located it within 5 minutes. Passenger side of engine atop the crankcase, the PCV hose leads to a vacuum nipple on the intake man. plenum close to the TB.

Like my other Subaru, Subie, there's a crankcase breather hose on each side cylinder bank valve cover. Each hose goes to the corresponding side of the air filter box. I already had spare hose in the 2 needed sizes, and even had a metal hose tee to complete the job in a parts drawer. This important part of the whole Gadgetman system of mods was zero out-of-pocket cost to me.

I pulled the stock PCV hose off, then the PCV valve. Sprayed it out w/ brakecleen and shook it to verify it's good-it still rattles. Replaced PCV valve, capped the man. vacuum nipple w/ a vinyl cap. Pulled driver side breather hose off airbox, added metal hose tee, added short piece of hose, pushed said hose onto airbox hose nipple. Ran new piece of hose from PCV valve to metal hose tee on breather-to-airbox hose.

Start engine in driveway, verify it runs OK, no evident issues.

Done. It took wayy more time to describe it all than it took to do it.

I'll add pic's here to help show how it looked. Ask questions, if unsure of what's going on w/ this mod.

Tracy G

Claudio,

Apparently the system doesn't like your PDF. In the future, how about just a JPEG or PNG or something?

Ron

PS: And just open your attachments, put the cursor in the message where you want the image to appear, and click Insert.

Save me some time here, bud...

Hopefully this picture helps and goes through. Take a look Ron thanks.

Claudio, I got curious re:your Acura's PCV valve. You said yours has no hose to it. I looked on youtube and found a video of someone changing out his on a V6 Honda, it was in a tight location w/ a bolt holding it down. The graphic you posted looks to show one that has a hose being removed. Is this graphic true to what's on your MDX?

After looking at an ad for the bolt-on PCV valve, plus the youtube clip, it looks like this bolt-on PCV valve uses O-rings to seal off the two ends that are in different chambers. I'd guess that one side is crankcase, the other is manifold vacuum...

I don't know if you've talked to Ron or anyone else about this PCV on your MDX, if you have it sussed out or not. In the past we have hashed out many PCV issues here, to try to bring more info to light.

Just 'ol me offerin' ta try to help if you want...

Tracy G

Hi Tracy, thanks for the response and questions. Yes that exactly the correct picture and my pcv valve set up. I work at a Acura dealership and took the picture from the service techs Acura manual. What I did was remove that hose and capped off the the ends on the valve cover and intake manifold. I don't know if there is more to be done to the pcv valve itself or leave it alone. Let me know if you come up with anything thanks.

OK Claudio. When it's idling, remove the cap from the PCV valve. See if there is vacuum sucking into the open PCV valve. IF there is, then the other end of it is getting manifold vacuum. So you want that capped off. BTW, I advise using vinyl or silicone vacuum caps. the black rubber ones usually crack within a few months.

Next, look around on the air cleaner housing to see if there's another hose between the air filter housing and the crankcase. The crankcase end might be on the valve cover, or someplace else on the engine.

Check this stuff out, then let me know what you find. It would probably help to post pics of what you find here too

Tracy G

Hey Tracy,
Did you find any benefit to the PVC reroute?
Have a 2016 Kia Sportage and the PVC is easy to work on.
Dont want to mess with either if there will be any chance of screwing
up the engine or performance. It has only 50k and runs blissfully smooth and do not want to
do anything that would negatively affect it.
I would like to have the groove done on this but the throttle body is kind of buried
with hoses attached to it. Dont want to mess up a good thing. Its my only vehicle
Pics are attached. The PVC is on the left side with the orange file on it and the throttle has orange file on the right side under hoses.

Tracy,
Did you find any benefit to the PVC reroute?
Have a 2016 Kia Sportage and the PVC is easy to work on.
Dont want to mess with either if there will be any chance of screwing
up the engine or performance. It has only 50k and runs blissfully smooth and do not want to
do anything that would negatively affect it.
Would like to know if the reroute is worth it to improve gas mileage or performance.
The two pics are one of the orange stick on the PVC on the left side of engine and the throttle body on the right side buried with the orange stick on it.
Would like to have the throttle also grooved but there are two hoses that attach to it and its buried under some hoses. Dont need any headaches trying to improve performance.

Hi kman-- I don't see any pics from you here. On my Outback, yes I did notice some improvement from the PCV re-route. I did it first before the Groove. Took it out on a 50+ mile night hiway run to test it, throttle response was better and low-mid range power improved some. Not a bunch, but enough that I could feel it.

I'd say, go ahead and try it on your car. Be sure you understand what this mod is and how to do it first. It's simple and easy enough to reverse if you want. Please do use the many posts already here in the forum that cover PCv re-route to understand it. We have explained and posted pics and Q/A on this topic MANY times in the past years, so take advantage if that if you need to.
Feel free to ask questions and post pics of your work too.

Tracy G

Tracy,
Will let you know when I try the exhaust reroute. Also would like to know about gapping plugs.
Have heard that some plugs should not be fooled with since the tip may be weakened and break off in the engine. Any suggestions on that? Also read that only Kia plugs should be used by a video I saw on Youtube. Looked like plug depth on the knock offs were shorter.
Dont know why the pics didn't go thru but when I previewed the post it looked like everything was fine and the pics showed up in the preview.
Also the reason why two posts from me is that I did post the first one and didn't see it posted the next day so I posted again. It seems like the posts do not get posted for a while so I guess I have to wait a day or two before they are.
I also posted on the exhaust system post and it has not shown up yet either.