2009 A4 TSI

[urq]

I thought these cars used "direct injection" ... i.e. the fuel is injected
into the cylinder directly as in a diesel motor ... nicht wahr?  It seems to
me that in a direct injection engine all that would be passing through the
intake valves is air ... perhaps with a little oil vapor ... 

Of course the exhaust valves would be a different story ... altogether ...

Steve Buchholz

-----Original Message-----
From: quattro-bounces at audifans.com [mailto:quattro-bounces at audifans.com] On
Behalf Of John Larson
Sent: Thursday, June 05, 2014 1:42 PM
To: quattro at audifans.com
Subject: Re: 2009 A4 TSI

On 6/2/2014 11:51 AM, Nick Lawrence wrote:
> Hello,
> I moved up about 2 decades in Audi technology and am getting a 2009 A4 
> Avant TSI.   I would like to know If there are knock sensors (most 
> likely), and how they function.
> Meaning if there is knock does the computer make changes and if it 
> continues to knock create a stored code?
> Is there ever any driver visible indicator that there is engine knock?
> Any insight will be appreciated.
> Nick   central Ohio
>
>
While I didn't work at a dealership in recent years, and I'm in a relatively
small city and had only a few FSI cars pass through my shop, I wouldn't own
one of them on a bet.  I'm guessing the TSI engines are essentially the
same, although updated, design.  While (when I was in the business) I could
offer only anecdotal commentary on this engine, I have found over the past
few years that I wasn't the Lone Ranger on my negative opinion of the
technology as applied by VAG.  Reading the help requests on iATN and
following the trade magazines has revealed that decarbonizing of the valve
stems, usually by media blasting, is pretty much required every 40-50K
miles.  This means you have to remove the intake manifold (not an easy or
quick job on the 4 cylinder turbos), blast the stems of the closed valves
(and turn the engine to close the valves on successive cylinders).  You're
looking at 5-10 hours labor + any gaskets, broken plastic hoses or
connectors, whatever.  When independent shops are buying the equipment to do
this job, you KNOW it's a profit center because it has to be done.

John
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