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Discussion Starter · #1 ·
There are already too many threads about this so I decided to add another since basically the out come of those threads prove the opposite of what happened to me.
My car was smoking really bad.You couldn't downshift while taking a corner without filling the entire intersection with smoke.After the car had warmed up at idle I would get alot of smoke.....some of the time.And smoke on deacelleration.....some of the time.Added both Krank-vents and it still smoked.Drilled out my PVC and reconnected the Krank vents.Pluged the return that goes from the valve cover to the intake and put a breather filter on the rear Krank-vent instead of a catch can. No more smoke.For 2 whole weeks of everyday driving. WHY? And the cheap little breather filter isn't spewing oil.
 

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It probably reduced your crankcase pressure, thereby reducing the amount of oil vapor that gets blown past your valve seals.

Just a guess.
 

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Did you plug the intake tract fitting for the hose from the rear valve cover, I'm not clear on your description, but I think that is what you meant. Was the fitting in the intake tract or the hose clogged. If the hose or fitting from the large KrankVent to the intake was not open, that could cause the condition you describe. It sounds like you have bypassed that hose. Also, what shape was your PCV valve in?

Jeff
 

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Discussion Starter · #4 ·
The PVC was new.The second new one in 2 weeks.Yes ,I blocked the return for the rear Valve cover at the point of entry into the Boot- sock whatever its called where the mas hooks into the intake track.That is totally removed and blocked.Since the rear Krank- vent is one way and will only blow outward I capped it with a cheap mini filter.Now I know this valve has no suction on it now but you should of seen the amount of oil being sucked/blown through the rear cover and into the intake.It was puddled to the point of it would pour oil if removed. Pic is of set-up now.
 

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Mike- makes sense really- you have no more vapour in the inlet track- thus none being burnt - it was mentioned before that a little oil on the manifold will burn as a TON of smoke... what's that old book's quote? A little leaven leaveneth the whole lump?

Seriously- you have no recirculation- that will help stop it- one other thing is that the amount of vapour you have is really friggen hot- once it is released into the air- it cools and would condense more- unlike being burnt to a crisp and thrown out the exhaust pipes.

I will consider doing this also- not because of smoke (I get none) but because I don't like any vapour in the inlet track (and I can't afford the catchcan yet) and although we don't have inlet tube pressure measured yet- once we do- it may end up that I am wrong, there is no vacuum in there and so this is as good as it gets.
 

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Yes, that solved the smoking problem. It did the same for me for a long time, until turbos wore too much and it started smoking somewhat again. Before, I could tell when the KV suction hose was kinking off under vacuum because car started smoking again once; fixed hose routing and smoke went away again. KV seems to make about a 50-95% improvement in smoking condition.
JT
 

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Mike,

I’m going to take a stab at you experience with KrankVents. This is my guess on the limited knowledge of your engine. I appreciate your willingness to describe your mechanical setup. I don’t have any smoke from my engine and there is a light film of oil on the intercooler tube exiting the rear turbo and nothing on the IC tubing going to throttle body from either side. I’m not sure if there is an oily film on the outlet of the front turbo, it hasn’t been off for any reason and hasn’t been checked.

I would be suspicious that you have more blowby and the stock PCV valve can’t keep up with the crankcase pressure, even under non-boost conditions. The excess fumes vent into the intake and oil condenses and eventually gets into the engine to be burned with visible smoke. Just adding KV’s and still having the PCV valve as a restriction wouldn’t change the venting of fumes into the intake tract. I don’t think there is any real suction created in the intake track on our engines. Drilling out the valve allows more flow into the intake manifold under non-boost conditions. Closing off the crankcase to the intake tract keeps oil out of the intake, pretty obvious. The engine is now burning the oil continuously while there is manifold vacuum without the visible smoke because there is no accumulation of oil being released intermittently. I have seen engines burn a quart of oil per 500-600 miles without smoking.

Do you hear any whistling or air moving with the drilled PCV valve. Do your intercooler hoses going into the y-pipe or the y-pipe have oil in them. Did the idle change with the drilled valve. I’m really interested in the positive result you have had.

Please feel free to tell me I’m full of BS, it happens regularly.

Jeff
 

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Discussion Starter · #8 ·
Jeff, The only thing that makes sense is that there is no oil being sucked into the intake since it is plugged.Before it was full of oil.And when I say full I mean where it is flexable there would be oil standing there.Enough to soak a paper towel.None from the turbos.All from being pumped into the intake track through the PCV valve or the intake pressure sucking it out of the rear valve cover past the valve.The weirdest thing is that the car is never down on oil.No more then what I would consider normal.It started at the auto cross at the NG and I wonder if all the slinging of the car caused a drain back to become plugged.It may just be the 10:1 compression and the boost overpowering the valve seals.I thought that the rear K.V. wouldn't allow flow into the intake track even if it were still routed through the intake boot and had intake pressure on it.I have driven it 8000 or more miles since all of this started and it uses no oil and runs fine.No whistle to the drillled PCV valve either.
 

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Mike,

I'm glad the KV's cleared up your problem, but it certainly is puzzling. I don't understand how valve seals could be affected by engine compression or boost. Usually when valve seals leak, oil is being sucked by the intake seal under manifold vacuum. Are you seeing any oil condensing around the breather filter you installed? After you are convinced that the condition is fixed, would you be willing to go back to the stock setup and see if the smoking returns. In the interest of scientific discovery, I would like to see you try that. Of course, since I don't have to do the work, it's easy for me to ask.

Thanks for your reply. It is of value, at least to me, when there is a good description of the condition, fix, and result.

Jeff
 
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