[200q20v] Re: [birabrakes] Audi 20V Turbo Crankcase
Breather System Tuning, help neede d !
pjrose at frontiernet.net
Tue Oct 31 11:56:17 EST 2000
This sounds exactly like the "problem" I recently posted on the 200q20v
list. My Michelin Man hose quite suddenly has started collecting large
amounts of oil (well, OK teaspoons full) very soon after my ecu chip
upgrade was done. Totally dry before that. I suspected the crankcase
breather as the source and thought it might be a defective pressure
regulator valve. Right now I'd say that my MM hose is acting as the
"settling tank", but obviously we'd all be much better off to have oil
condense before reaching the IC, MM or IM.
In normal spirited street driving, the oil from my car that's "lost" this
way appears to amount to no more than 1/2 qt in 2-3K miles. That upper
limit assumes none of the total drop in oil level is from from other
reasons (burning, etc). But in any case it makes a mess of the MM hose and
I'd like find a fix, if possible. Perhaps there's room for a "settling
tank" to be fitted in the breather hose line near the right/rear corner of
the engine just before the cranckcase pressure regulator valve. In fact,
possibly the high-pressure washer bracket could be used to secure it. Seems
all it would take is two short lengths of rubber hose, 4 clamps and an
appropriate container. But would it stay cool enough back there to condense
most of the oil?
At 9:24 AM -0500 10/31/00, C1J1Miller at aol.com wrote:
>In a message dated Tue, 31 Oct 2000 6:40:05 AM Eastern Standard Time,
>tommy.arnberg at nokia.com writes:
>As you all know the breather system is closed
>and when boost is a little higher than stock,
>then the crankcase ventilation system in 3B
>engine (200 20V) pushes the polluted oily air fume back
>to Turbo charger "mouth"
> * fuel octane rating in mixture to be burned gets lower
> * Inter cooler cooling ability gets worse because of oil-air fume
> * the inlet valves get burned oil build up (the worst of all)
> * air into engine gets warme
>The operation of the crankcase breather hose is explained in detail on Scott
>Mockry's excellent (as always) pages, here:
>"This breather hose is routed around the back of the engine and one end
>connects to the round black crankcase pressure
> regulator valve near the back of the valve cover. This black regulator
>valve, controls the flow of crankcase fumes to the turbo
> intake boot. The valve has two ports inside, one is approximately 0.400
>diameter and a smaller one that is approximately
> 0.180 inches. The larger port and the smaller port are open during low
>boost operation but when the turbo makes enough
> boost and flows enough air to produce a vacuum on the suction side of
>the turbo, the regulator valve diaphragm sucks closed
> and blocks off the larger port. This leaves only the smaller port open
>to flow crankcase breather fumes. "
>There is more, including a diagram, but the basics are that the breather is
>mostly closed off during higher boost conditions.
>The Gastank ventilation is operated with the
>"Blue valve" to inlet manifold. The piping has a
>valve that prevents back flow from inlet manifold during boost
>condition and during vacuum it sucks the air from crank case and
>through the blue valve from gas tank ventilation system.
>Has anyone disconnected / modified the stock system following
>way or better way ? what is the right way. (I know this is not
>legal but otherwise the engine gets older a lot faster !)
>[ Crank_breath.ppt ]
>If someone knows good product that solves this problem,
>please mail www-pages and/or source for it !
>Looks to me like you want an oil collector system to limit oily vapor from
>being combusted. I've seen other turbo cars install a "settling tank" where
>the vapor can collect, condense, and later be drained...
>Tommy: can you store that file somewhere that the 200q20v owners can access
>On my car, with 5000 mile oil intervals, I burn very little measurable oil;
>perhaps 1/2 quart at most?
>200q20v mailing list
>200q20v at audifans.com
* Phil & Judy Rose Rochester, NY *
* mailto:pjrose at frontiernet.net *
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