[Biturbos4] White smoke
koenigj at comcast.net
Wed Jan 28 11:12:35 PST 2009
The problem with freezing and blockage in the PCV system is actually well known.
Somewhere I have a copy of an Audi Technical Bulletin on the subject. If I can find it
I'll post some more details.
----- Original Message -----
From: "Aurangzeb M. Agha" <ama-list at mltp.com>
To: "Greg Amy" <grega at pobox.com>
Cc: <biturbos4 at www.audifans.com>
Sent: Tuesday, January 27, 2009 12:10 PM
Subject: Re: [Biturbos4] White smoke
Hi Greg --
Yes, I am in fact somewhere very cold: just nort of you in Western Mass.
This is really intersting. Thanks! I'm going to definately keep an eye
out to see if this issue happens again (it's hard not to). Here's what's
happened since I last posted:
I took my car to my regular mechanic, and after driving it around for a
while and checking the car out, he called saying that basically there's no
oil showing on the dip-stick. This, after I'd gotten the oil changed just
two days before.
Here's *his* theory: Oil in the engine gets thicker as it's used more.
Since it's been 7K since my last oil change *and* since it's been so cold,
he thinks that after the oil was drained and the new (thinner) oil was put
in, it "seeped into places the older, thicker oil hadn't been in" and this
might have caused the huge smoke output.
Does that sound legit? I don't know.
Does it work for me? I drove the car around yesterday after more oil was
put in the car (to top it off) and in to work this morning, without issue.
So, for now, "yes".
On Mon, 26 Jan 2009, Greg Amy wrote:
:> Subject: [Biturbos4] White smoke
:Advanced apology for the mucked-up headers, I'm on digest.
:Dude, I'm gonna make your day: it's probably not the turbo(s).
:I'm guessing you live in a very cold climate? Someplace where it's below freezing right
now? If you are, then rest easy: your PCV system is probably frozen.
:Same thing happened to me last winter, freaked me out. I thought for sure I was about to
spend $10k plus with APR (in for a penny...) Did some research - can't recall where I
found this - and the symptoms matched.
:That's the good news. The "other" good news is that it's a relatively cheap part. The BAD
news is that it's a MAJOR PITA to fix. What you have to do is remove and replace the
"octopus" breather system under the intake manifold (part number 078 103 235B or J,
depending on your VIN). It's a series of plastic hoses that connect together all the
intake and valve cover fittings for the PCV system.
:I don't recall if the Bentley says to remove the intake, but I suggest it would be
"easier", if you feel up to it. I tried it without removing the intake, and while it can
be done it takes patience. Lots of patience.
:Alternatively, I suppose you could remove the octopus and clean it out -- it's probably
clogged with oil and water vapor, and freezes up at night, causing the system to
pressurize and blow oil out the valve cover and into the intake - but by now it'll be all
brittle and you'll probably break it anyway. Since you're in there, buy a new one.
:To check and see if this is actually the problem, note whether it does the white smoke
ONLY when below-freezing temps are around, and also ONLY when the engine is stone cold.
And/or, trying leaving it in a heated garage overnight to see if it still does it. I think
you'll find a correlation with outside and engine compartment temperature.
:Mine has never done it again since I replaced that hose. And we've had some pretty
serious cold up here in CT.
:Now, if I could only find a cheap airbag computer to replace the one that died during
LAST winter's sub-zero temps...sigh...
:Have fun. I did. - GA
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