Death to PCV

[timothydog]

I'm getting fed up with my PCV system. It is sucking major oil into my throttle body. The valve itself is not a Delco part (it's the "douche" brand) but it is brand new. I have a breather on the passenger side valve cover but not on the driver side. I don't have the check valve either.

What is going on? As soon as I clean out the vacuum block and gasket it gets freshly oiled after one drive.

Suggestions anyone? .. before I cut the damn hose!!!

 

[turbov6man]

Go with the Pete Tomka style check valve and get the correct GM pcv valve. No worries then.

Good Luck

Brad

 

[REDS HOT AIR]

PULL HOSE OFF AND PLUG

oil is our worst enimy ....no pcv here

 

[6=8]

Oil Filter/Breather?

I know that another source of oil is the breather setup, where the line runs from the valve cover breather behind the turbo to the turbo inlet. You may try plugging this line off for a run or 2 and see if this reduces the amount of oil you are finding. It may be so bad that you have to drain the oil out of the I/C before you see any results!

 

[timothydog]

I removed the breather line that went from the valve cover to the turbo inlet bell. That was one of the first things I did 3 years ago. I capped the bell and bought a K&N type breather from ModernMusclecar. I still have the stock oil fill tube on the driver side though.

My turbo has about 300 miles on it and I cleaned the intercooler at the time. I'm sure there is a little oil again now though.

REDS..
Your proposition intrigues me. I would love to plug that sucker up! Will the crank case be properly ventilated without the valve though? And if not, what is the worst that can happen?

 

[REDS HOT AIR]

worst case i know of is oil will get dark sooner

my oil seems to be just fine but then again how often do we change our oil ?

factory recomended every 7500 miles so i dont see no downsides to it.

the only time it does anything is when you have vacuum and if you drive like me mines not on the vacuum side of the gauge too often.

only thing it does if pull fresh air in the breathers and pulls fumigated air into the intake.

to me i'd rather change my oil more than have oil residue in my intake and be getting knock.

i ran my hotair and my i/c motor with no pcv and havent seen no downsides to it.

i just leave the pcv valve in the hole and plug it where it comes from the t/b or even better put vacuum brakes on it and run your hose to it..

 

[azgn]

no PCV here...just change your oil often

 

[blackbuick87]

Well I guess I am going to plug that sucker!

 

[ijames]

I tried running with the pcv plugged one winter and after a week the oil stunk of gasoline and there was rust on the inside of the oil fill cap. You really need the pcv on a street car. I've posted about my setup before, but briefly, remove the stock two metal lines for the pcv and boost. Run the boost up to the top of the doghouse. Come off the pcv valve with about 2" of hose, then insert a Fram G3 fuel filter. This is clear so you can see the oil collect and drain back, and has 3/8" fittings to match the hose. I try to keep the filter vertical for good drainback and install it so the letters are right side up. Come off the filter with anther 2" of hose to your check valve, then from that go to the top of the doghouse. My throttle body used to get black in 5000 miles but now I can just see a gray film after maybe 25-30000 miles. I've run this setup since 1997 or so, about 60,000 miles, with no problems. In fact I just replaced the filter last weekend because the heat finally made it brittle enough to crack. Oh, make sure your check valve has minimal cracking pressure. It should seal immediately when you blow into it, and you should be able to inhale through it and barely notice any delay or restriction. If it takes too much vacuum to get it open then you won't get enough flow through the crankcase.

 

[TurboDave]

Please, whatever you do, DONT run without a PCV. Not on a daily driver!!!

Why not just get the correct part. Damn, they're only a couple bucks, it's not like a budget buster

You do have the correct intake gasket with valley pan, right????

 

[REDS HOT AIR]

my oil is always fine but the total seal rins could be helping that and most of the time i see up to 100 miles a day with it.

10-30 valvoline
always clean coming out and dont smell like fuel

 

[Chris Taylor]

Guys you need the PCV valve. I use the correct AC valve, it works.

 

[Tow Man]

Originally posted by TurboDave
Please, whatever you do, DONT run without a PCV. Not on a daily driver!!!

WHY???

Here's my .02 on this subject with a little history! The PCV system was introduced in the mid to late 60's as an emission control device! Instead of venting the crankcase to atmosphere (pollution), fuel vapors and oil smoke are routed back into the intake charge and burned! This is the PCV's ONLY purpose!

As long as the crankcase is vented sufficiently, there is no need for the PCV valve unless you are a enviro 'mental' ist! This makes no difference whether N/A, supercharged or turbocharged!

If the crankcase is not properly vented, yes you will have more fuel and sludge buildup. You will also blow oil out of every crevice due to pressurization of the crankcase from blow by, especially in turbocharged or supercharged engines!

The PCV valve does nothing at WOT except maybe leak boost pressure there by causing more crankcase pressure and hurting performance! The check valve sold for $20.00 is to prevent leaking boost pressure, not keeping oil out of your TB!

If you run a breather on each valve cover, you should be perfectly fine without a PCV valve.

In short, PLUG IT

OR rig up a Road Draft Tube LOL

 

[timothydog]

Can someone please explain why oil gets sucked through the PCV valve? Is it blow-back from after the crank case is boosted?

 

[TurboDave]

Originally posted by Tow Man

Originally posted by TurboDave
Please, whatever you do, DONT run without a PCV. Not on a daily driver!!!

WHY???

Here's my .02 on this subject with a little history! The PCV system was introduced in the mid to late 60's as an emission control device! Instead of venting the crankcase to atmosphere (pollution), fuel vapors and oil smoke are routed back into the intake charge and burned! This is the PCV's ONLY purpose!

As long as the crankcase is vented sufficiently, there is no need for the PCV valve unless you are a enviro 'mental' ist! This makes no difference whether N/A, supercharged or turbocharged!

If the crankcase is not properly vented, yes you will have more fuel and sludge buildup. You will also blow oil out of every crevice due to pressurization of the crankcase from blow by, especially in turbocharged or supercharged engines!

The PCV valve does nothing at WOT except maybe leak boost pressure there by causing more crankcase pressure and hurting performance! The check valve sold for $20.00 is to prevent leaking boost pressure, not keeping oil out of your TB!

If you run a breather on each valve cover, you should be perfectly fine without a PCV valve.

In short, PLUG IT

OR rig up a Road Draft Tube LOL

Actually it serves two puroses. Emission control as you said, But also, to positively vent the crank case. Helps keep the condensation and other chemical contaminents pulled out of the crankcase.
Run without one on a daily driver and it wont take too awful many miles before the condensation and chemicals left behind start taking their toll, and deposits start building rapidly.
Corrosion, gas in oil, etc. all nasty things that don't need to be there at the benifit of plugging a $3.00 part.

 

[TurboDave]

Originally posted by timothydog
Can someone please explain why oil gets sucked through the PCV valve? Is it blow-back from after the crank case is boosted?

There are a couple of reasons. Wrong PCV (sucking too much vacuum). Believe it or not, for such a cheap little part, they actually are calibrated to pull a certain metered amount of vacuum. Wrong PCV, wrong vacuum amount; screws up the MAF calibration (un accounted for vacuum).

Also, if the wrong intake gasket (the one without the valley pan) is used it can suck all the splashed oil in the valley.

 

[Buick Mark]

Theres a constant mist of oil all around the crankcase from the spinning crank, rotating rods, pistons going up and down, and from the cam and lifters, this gets sucked in the PCV even with the correct intake valley pan, and is hard to control because of the relatively small crankcase of the engine. I have tried plugging the PCV and this seems to work the best, but as Dave has said it will mess up the MAF calibrations. Right now Im using my own "PCV oil /air seperator" so I can still use the PCV without the oil mist getting sucked in the throttle body. It seems to be the best of both worlds Mark

 

[ULYCYC]

I remember working on engines before PVC valves (yes I'm old) I remember scrapping out 1/2 thick sludge out of the valve covers oil pan and block walls. Some of this was due to oil quality back then but most of it was from moisture that settles in with the oil and makes sludge. The PVC pulls out most of it even with open breathers.

 

[blackbuick87]

I want to leave the valve in but cant you just vent it to the air or as some have said put a filter on the end? I would rather not have the oil in the TB

 

[Alky V6]

You should keep the PCV for a street car. On my old motor and with the new one I use clear tubing from the valve cover breather caps to a catch tank on the firewall. The clear hose was used so I could monitor the oil content in my blowby. I did not use a PCV valve at first. You need to know that the largest by product of burning methanol is water. In fact, the car looked like a steam engine at times when I had the full exhaust system on it. The water would collect in the exhaust system during warmup and start burning off after the system got hot enough. I noticed right away, moisture collecting in the clear tubes(BIG OL DROPS). Of course that meant a lot was collecting in the engine also. Without some form of ventilation that water had no where to go but to settle in the oil pan. I decided to put the PCV valve back in and absolutely zero water collected in the tubes. I did experience oil in the intake after that (OEM valve). Since I wasn't using an intake gasket with a valley shield, I made a oil seperator and epoxied it to the bottom of the manifold. It helped quite a bit, but I still was getting oil. I have since heard of putting a .030 orifice before the pcv valve to slow the volume going to the intake. I,m going to try that next. I like the inline filter idea too. I know the water content is not as great with gasoline, but you do have some. One of the first things I learned in auto shop class as a kid was how important the pcv or any form of forced ventilation (vacuum pump) was to keeping the crankcase clean. For a race motor that is constantly torn down, don't worry about it. For a street car, it's a must. My race car will have it because I don't want to rust my carrillo rods or anything else for that matter.