How to check for sludge ?

[NIck Miller]

The eg temps post turbo can see ranges of 1500 pretty easily,  with temps
right at the manifold to turbo inlet flange reaching 1800 or better,
especially on cars with a small turbine, like the A4.  Despite this,  turbo
compressor outlet temps are only in the 200s at most typically.  Its highly
likely that valve melted from residual heat from the turbo.

Ceramic coating and heat sheilding will bring underhood temps down a ton,
easily, by keeping heat in the exhaust and off of other things.  Only oem
I've seen use ceramic is mercedes though.

And also,  I don't know if its the engines themselves so much as/ the owners
and their driving styles.  You must do an afterrun with a turbo car after a
hard pull otherwise the cast iron turbine housing retains enough heat to
boil the oil in its lines after coolant and oil stop flowing through it.
You can hear this happening if not cooled.  I usually use 45secs as my stuff
is a few grand to replace.

As well, my engine made 230whp for a 1.8, and I changed the oil every 5k
with mobil1 or valvoline synpower 10w30,  with 40k miles on this setup I
pulled the engine valve cover off and its spotless.  Every now and then
tolulene went into the fuel to keep it clean, and I. Tracked this car and
beat its face off, but the motor is  in good shape and clean.  I doubt its
the motors power output to size,  but the stop and go driving without
cooldowns using regular oil that sludges them up.  As well as the formula
for oil being watered down by the epa.

Bmws with vanos have a similar sludge problem too if not ran with synthetic.
On Nov 3, 2010 9:48 AM, "thejimrose" <thejimrose at gmail.com> wrote:
> nice writeup tony. it's my suspicion as well that that newer cars, given
> higher hp, stricter mileage and emissions requirements, etc are much
harder
> running motors. couple that with fewer / further required maintenance by
the
> oem's and it seems sludge is one of the many outcomes.
>
> my little 1.8t was 1 of the most notoriously sludgerrifical motors ever,
and
> she was whistle clean at 170k. PO's had the good sense to change the oil
on
> a reasonable interval w/ good oil and pay some attention to warm up / cool
> down. i always did the same, highly scientific "use? oil. change? sure"
> approach to the a4.
>
> funny.. when i bought the car there was a little label that the PO had
made
> [very official looking, black typeface on clear sticker] that said "TURBO
> COOLDOWN - 20 SECONDS" stuck in the corner of the rear view mirror. THAT,
> more than anything, sold the car.
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