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Ask Javad about this one. He diagnosed this issue for me a year or two ago.

My 80tq will smoke (a lot) out the tailpipe on decelleration if the crankcase breather is not hooked to a vacuum.

My guess is the pressure differential in the valve cover helps the valve seals do their job?
 

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Yea, I'm getting the same smoke with the breather on the valve cover, and I'm venting the main crank case. The NG motor doesn't have a valve cover vent, granted it's not a hi po motor. I'd like to get it under vacuum, but I don't really know how it's going to happen. I was going to go with one of those crank case evacuation systems, but on second thought, I don't want my mufflers filling up with oil, and to put it after the mufflers means one long ass hose, and probably oil all over the back of my car.

I was going to try a venturie tube in the intake with an aircraft grade seperator, but I'm going to be trying some ram air systems that will screw that up.

Anyone have any ideas other than running one of those huge dragster vacuum pumps?
 

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auditurboquattro said:
Ask Javad about this one. He diagnosed this issue for me a year or two ago.

My 80tq will smoke (a lot) out the tailpipe on decelleration if the crankcase breather is not hooked to a vacuum.

My guess is the pressure differential in the valve cover helps the valve seals do their job?
Crank case vaccum helps the piston rings seat.
 

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Jim, w/o the vent the valve cover will fill with positive pressure, BTDT too many times. Valve guides are not completely air tight and pressure builds. Typically this manifests in oil leaking all over the front of the motor and often oil in the exh.

I know what you're saying about clutter, and all it might need is a 3/8" line at the back of the valve cover venting to atmosphere, but anything to relieve the pressure is necessary IMO. NG wasn't turbocharged, even the Audi Sport race cars had big vent hoses from the valve cover to the turbo inlet.
 

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Guess I should keep that 2nd 7A valve cover I have from the good 7A head. For some reason, it has a breather port on it. The other one doesn't (and shouldn't). I've only found it (plugged up) on 3B's and RR's. It's in the same position as the KW's head breather port, just smaller (around 8mm IIRC).
 

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Yes, that's a good example as well, 7A aren't vented, but the 3B and AAN are (as turbo applications).
 

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here's an idea, find a small smog pump and plumb the vaccuum side into your crankcase and put some kinda filter on the end. you probably check the oil regulalry anyway like i do, so oil consumption is normal to me, course, my turbo is about ready to take a dump. but this would put a vacuum at least.
 

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if you could make something work off that, and then have it pump the oily air through an oil separator in which the oil build up could run back into the crankcase.
 

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Hmm, I sorta like that idea, using an airpump off a newer VW for example, basically a big fan that pumps air, I'd look into that, runs off 12v.
 

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oooh, if it runs of 12v that'd be even sweeter!!
 

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no ya goof, a belt, like every other smog pump in the world :wtf:
 

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derracuda said:
no ya goof, a belt, like every other smog pump in the world :wtf:
and where would this belt be attached to?a cog connected to your feet?
:slap:
silly boy...
anyways if makes you guys feel better i usually have a vent can which eventually vents to atmosphere because i hate having oil in my intake manifold.Looks nasty after a couple of months in there.
 

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You pedal your alt. Wiz?
 

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whooop....i think outta the loop here nate :D
 
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