[V8] V8 Crankcase Ventilation (PT/ABH)

[Dave Saad]

I agree (I think)
It is beyond my skill to redesign the pcv system, but I do know about the 8 qt fill.
I went so far as to cut an inch off the dipstick tube so I could run down below 8 qts and still see oil on the dipstick. I am happy with that. 
Replacing the rings did help a lot too. I also rebuilt the heads. 
The plugs never did look that bad before the ring job. I don't know why because they were swimming in oil.
Anyway I now just accept that the motor is in good shape, and it uses oil.
It always bugs me though that my 200K+ mile explorer has had almost nothing go wrong with it, and it is burning a quart about every 3000 miles now.
Since the change interval is 5000 I add one qt per change. This started about 170k.
On the Audi I think I might just change the filter once a year and call it good.

Dave

Sent from my iPhone

On Oct 3, 2012, at 3:54 PM, Scott Justusson <qshipq at aol.com> wrote:

> ....  Except one might argue that you are consuming waay too much oil?  If the rings are good, the valves are good, why would this be?  Er, could be a bad PCV system!
> 
> I got involved in this back in the mid 90's with a customer that bought his 91 v8 5spd *new* and documented with Audi, dozens of complaints of oil consumption and visual oil plumes.  He complained so much in fact, that Audi bought him a brand new engine complete at 60k.  Less than 4 months later, the documented complaints started again.  During this time, Audi changed from a 10quart capacity TSB to a 8 quart fill on the v8, a TSB stating that 700miles to 1 quart was 'normal', and all but ignored the issue.  How do I know?  I reviewed every document, rebuilt his new engine with 30k on it, and convinced the guy that the real fix was a total redesign of the PCV.  And, it wasn't going to be cheap.  That got him to just sell the car and the 4 boxes of receipts to Ingo.
> 
> I might also look at the 'need' to do rings much differently, that possibly the need is because there was too much oil in the combustion chamber causing hot spots resulting in premature ring blow-by.  Once I saw an Audiport built v8 with proper PCV ventilation, I realized this is probably the biggest non recall in History.  Best case, the v8 got a bad rap for oil blowby issues that was simply from a bad design.  VAG doesn't have a lot of 'good' PCV systems, dating back to the Mk1 I4 engine.  BTST.
> 
> IMO/E this isn't conspiracy theory, this is just plain bad design of PCV.  I suspect a lot of the reason it was designed on the v8 engine was really to accommodate the sound insulation of the engine covers and fresh air intakes.  
> 
> I have studied PCV over the years mostly by necessity.  Long after most just install a catch can, I found that to be a poor and messy bandaid to a properly designed PCV.  And what most don't realize (esp in the turbo cars), that PCV airflow is matched to the engine, read:  Change the engine, you change the balance of PCV airflow through it.  
> 
> And some of us stare at a 1000 mile per quart consumption as nuts on a 8-10quart oil system with an oil thermostat and cooler.  Me especially, as I have installed a supercharger on my 4.5l I6 with the same oil capacity and 'no' cooler, and I don't go through a quart of oil in 5000miles.  How did I do that?  Changed the PCV design and valve to work properly.
> 
> I'm actually thinking anyone that isn't riveted to the results GT finds, has becomed numbed to the problem that has been nagging these motors since they were built 22years ago.
> 
> IMO, IME, and my .02
> 
> Scott J
> 92 v8 4.2 ABT Chipped
> 
> 
> 
> -----Original Message-----
> From: dsaad <dsaad at icehouse.net>
> To: v8 <v8 at audifans.com>
> Sent: Wed, Oct 3, 2012 3:13 pm
> Subject: Re: [V8] V8 Crankcase Ventilation (PT/ABH)
> 
> 
> 
> It's deja vue all over again...
> 
> I think I wrote this exact
> screed a few years ago!!
> Ultimately I ended up replacing the rings -
> which cleared (literally and figuratively) things up.
> My car did all
> the same things yours does - especially the cloud of blue smoke after a
> long downhill decelleration.  In fact, the motor would die if I put
> the clutch in after a long downhill.  I still have the problem where
> if I park on my very steep driveway, I get a big blue cloud on
> startup.  The rest of the time I think I am in the "normal"
> consumption range. I havent checked it in a while but I suspect I use a
> quart every thousand miles or so.  I think of it as a running oil
> change :-)
> 
> Dave
> 
> 
> > We all know the CV
> (crankcase ventilation) system on these engines 
> >
> "blows"! Really, the poor design of this system literally blows
> oil into 
> > the intake stream as it does not have good
> separation/condensation 
> > characteristics. 
> > 
> >
> Not a rant, just a fact. 
> > 
>