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Here I go again....PCV

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Behind, in front of the throttle body it's as clean as a babys butt. :) I can find the oil residue in the tube coming from the pcv, and I've since installed a oil/air seperator in line here and it collects plenty of oil. :(
 
opzWE4,

Got ya.
1- how old is your motor? and Miles?
2- Have you had the bonnet off and when?
3- is there more oil in the intake plenum then behind the throttle blade?
4- did you ever pull the egr valve and notice oil in there?
5- does the engine smoke?

Steve K.
 
1. Original motor, 83,000 miles on it. New valve springs last fall, compression test showed a high of 168, low of 164, most cylinders were right together.

2. I had the intake off two weeks ago to try to fix this problem. The engine looked clean inside, no sludge or buildup really. I cleaned everything up, mildly ported my lower intake, and installed a new valley pan gasket. I worked the front of the vp to try and prevent the oil return from splashing oil on top of the valley pan. Then buttoned everything up. Ran great afterwards, just didn't solve the oil problem, although it may have helped a little.

3. About the same, may be a little more in the plenum.

4. Had the EGR off with the intake, and didn't really notice any oil, more of the crud that is in there. Cleaned it up though.

5. Engine doesn't smoke until it starts injesting oil, that's really how I found this problem to begin with. Everything will be fine, drive it a little, maybe get into it, then at idle it would start smoking like a freight train. I pulled the intercooler to TB hose and it was clean as a whistle. Opened the throttle blade and and saw oil all behind there. cleaned everything up and the smoking goes away, until it starts pulling oil again. I actually plugged the pcv for a while and that fixes the problem. That's why I've been chasing this thing for so long, worried about not running the pcv. :(
 
Yes, I have a aftermarket valve covers with a breather on the passenger side front, and one on the oil fill tube.
 
SKturbo,

To answer your questions,

1- My old Race car had a PCV down to 9.0 when I had to use a converter that stalled 4500+ and couldn't drive it to work any more it was 30 miles away. But I did install an evac system on it at that time.

2- The PCV is needed on street cars to help pull gasses out of the crankcase.

3- I don't know what they did without PCV valves pre-74, but I do know they had problems with oil contamination and sludge.

4- Same answer as #2

Did I pass?:rolleyes:
 
clean86,

No you did'nt pass.
The pcv vave does more than pull gases out of the crankcase.
What is the purpose!!!!!!!!!!!!
Was your old race car a turbo Buick?

Steve K.
 
I know it does more that pull gasses out of the crankcase,just didn't want to get into everything it does do.Like keep fuel that slipped past the rings from sitting in the crankcase and getting to the berrings for one.

No my last race car wasn't a TR it was a single turbo stroker mustang:eek:
 
opzWE4,

Ok, block off your pcv hose and the pass side breather. See how much oil,smoke or pressure you have coming out of your d/s breather hole.
If you dont have any or not very much reinstall your breathers but keep pcv line pluged. Clean your throttle body,vacuum block. Drive your car like you would any other time.
For a couple of days. Check your throttle body again. Then get back to me. Here or you can call me 9:00am to 9:00pm EST.
If you get the answering machine picks up leave a # I will call you back. 856-881-3235

Steve Kaminski
 
ill explain an incident that happened to me.

my car had a ATR pcv in it. since it was brass and expensive looking, i never bothered to change it.

i installed the same pcv on my new engine along with taller valve covers that use two drivers side style breathers on each side.

i had oil dripping off the chrome shields on the breathers and right on to my headers. i was smelling burning oil for about 2 months. i thought maybe the rings were taking a while to seal.

i finally couldnt take the smoke anymore and decided to check out the pcv. it was completly blocked. i put on a gm pcv and the problem was solved.

so in my opinion, turbo buicks need a pcv.

the pcv was put into widespread use in 1974, before that people just had to deal with faster oil contamination and fumes out of the motor.

hey keith, whats a jersey style pcv? i already have a jersey style THDP, so maybe i should get the matching pcv.:D


hth

surej
 
Clean86,

"MUSTANG" :eek: Do these guys know you had a Mustang?

Anyway the only purpose of the pcv system is to pull fumes from the crankcase, feed them back through the combustion chamber and burn them. So you dont vent them into the air.

Steve K.
 
so then to prevent oil burning off of my headers, would it be better to put a small breather where the pcv valve goes and block the pcv?

Gm had a lot of air being sucked out of the crankcase by the pcv and the original valve cover to turbo vent system. there was obviously a problem if they did all that. so that means the pcv was insufficient to begin with.


surej
 
Man whats the longest running post?

Dr Boost,

If your pcv being blocked was the cause of the oil coming out the breathers. Then what was happening when you were in boost? Because the pcv closes when you are in boost.
Gm had two systems of crankcase evacuation on the turbo Buick.

The p.c.v. system. but that only worked until boost. The line from the valve cover to the turbo would evacuate the crankcase under boost. Because most of the pcv valves would not close all the way under boost and would pressureize the crank case. But when it came to modifing the cars that had to go due to oil contamination under boost.

Steve K.
 
I dont know what buicknasty is talking about. This is a real problem and not a joke.:mad: :mad: :mad: :mad: :mad:

Steve K.
 
As I have mentioned before, I blocked off the PCV and ran my car for about a week. No more oil in the plenum, no smoke on start up. There was no smoke or vapors coming out of the valve cover breathers at idle either. Hate to beat a dead horse here.:D I am seeing just over 22" of vacuum at idle if that helps. Idle RPM is around 800. This is with a Comp 212/212 cam. HTH
 
PCV??

Can I ask a ?? Gonna anyhow....
If the pvc is designed to pull crankcase vapors out of the engine during normal, vacuum operation, why would you want to put a bunch of breathers on the top of the engine?
Seems to me that the air circulation would be from the breathers, into the top side of the lifter valley,[assuming a stock pan style gasket] and into the pcv hose to the plenum. The majority of the fumes and oil mist, being heavier than hot air remains in the area below the crank, and not readily available for transport to the plenum.
However, this changes as the engine rpm increases and the engine comes under boost.
A. The pistons are now more like a compressor w/ the added speed. There is added areation due to oil on the rotating assembly.
B. The crankcase is getting some degree of pressurization due to blowby.

Having said that, then question #2 is:
Does the above change in conditions cause enuf oil vapor to present itself for pickup by the pvc to cause the contamination??

Also, what about the hi vac conditions on decel? Couldn't the hi vac possibly pull some oil thru the seals on the valves and also even the intake gasket?? This manifold, being open, allows all cyls to "see" what's happening "next door"..

Being the old fart that I am, I've been around racing and engines for nearly 50 yrs.. I have seen the "sludge monsters" of the 30's thru the 60's. I've also seen my share of pcv engines that were a real mess cause the pvc didn't keep the fumes at a tolerable level.
This is on street engine applications...Race engines?? a totally different animal...
FWIW, I have a BUICK stage engine w/ a stock PVC system and a Delco PVC... Breathers on both covers.. I also crank the boost to 25psi... no smoke problems here.. Luck?? I don't know.
Also, I am wondering about the <1% leakdown:eek:

Back under my rock!
PS: am still going to try my vac pump idea...:cool: ;)
 
PCV in the "old days".

Before the PCV valve was used to "control" crankcase ventilation, there was a closed crankcase, with a vent line to the air cleaner. When the engine got some miles on it, enough oil would come out of the vent line to oil up the air cleaner, even though there was a separate little filter in the vent line. The air cleaner would get black and nasty on the side where the vent line plugged into the air cleaner housing. (This didn't work with open element air cleaners, obviously) This did the emissions thing, by putting the vapors back into the engine, but there was no "suction" to pull stuff out of the crankcase. That was CV (crankcase ventilation) but it wasn't POSITIVE, so it wasn't PCV. In the REALLY old days, the crankcase was just vented to the atmosphere, usually down low under the car. When the engine started to have a lot of blowby, there would be big clouds coming from under the car. But up to a point, it kept the crankcase fumes from condensing under the hood, making things get nasty. Vents on the valve covers will let things get nasty, if you haven't noticed. Of course, folks who clean their engines often, and don't drive much, won't find that to be much of a problem.
 
Chuck,

Your first question. As your pistons come down they are building pressure in the crankcase. Plus any gaped piston ring is going to have some blow by. You need breathers to have a place to relieve the pressure under acceleration.

Question#2. There are many reasons why there could be oil in the intake. I've seen Buicks that had oil coming in through the egr valve into the intake. Oil was coming down the exhaust valve steams and getting sucked through the egr system into the intake. These owners had been told they had pcv and blow by problems even needed motors by other "Turbo Gurus"
First everyone has to understand what could be going on. You can ten Buicks with oil in the intake. And have ten differant reasons why. example: wrong PCV,no intake valley pan,the dreaded blow by,synthetic oil in a fresh motor,no valve seals & bad guides on the exhaust valves,leaking compressor side of turbo,bottom of intake gasket leaking,compression sneaking past the head gaskets, to name a few. Plus you have to keep in mind you will get a small amount of oil in the intake with a pcv.But not enough to make it smoke.

Sorry this is so long. But thaks for reading it.:) Where did you get your rock? Sometimes I wish I had one.

Steve k.
 
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