Installed oil pressure gauge -- sludge problem

[Brett Dikeman]

On Jul 23, 2005, at 9:22 PM, Arthur Marks wrote:

> It would come from the heat of a turbo along with the dino oil and  
> 10000 mile oil changes that were originally specified by Audi. (The  
> problem with my car began before the change)
>
> I can open the oil filler cap and see the black gunk everywhere.
> I did an oil change myself (according to the new filter and oil  
> spec) within 2000 miles after buying it because the oil light came  
> on. I scraped some of the tarry substance off with my fingernail  
> then, and you can still see the clear shiny mark. So seems like no  
> new sludge. The light came back on 1000 miles later after driving  
> for 5 hours.

The oil change reminder light comes on after fixed intervals, unless  
you've recoded the ECU AND the car is capable of dynamic oil change  
interval determination (this has been true for euro cars for a while,  
but I have no idea when US cars started getting the sensors, if at  
all).  This usually involves a mass flow sensor in the oilpan.

If you were running synthetic, it is normal for the detergents to  
cause existing sludge to clean up; this is sometimes why synthetics  
will cause an older engine (previously run on dino oil) to leak  
around seals that were dry because it dissolves gum/varnish around  
the seal. It would also be expected that the sludge would cause the  
oil to thicken, maybe clog up the oil filter a bit, etc.

If you want to accelerate the process, go to the auto parts store,  
and buy a can of "engine flush"; it usually looks like an old- 
fashioned oil can.  Stay clear of the "slick 50" stuff; teflon is NOT  
for your engine.

FIRST make sure adding the can won't overfill the engine, or you'll  
burn a lot of excess oil and damage the emissions system.  You might  
have to drain a bit of oil.  Follow the instructions on the can  
precisely with regard to time limits and RPMs.  Usually you add it to  
a cold or barely warm engine, run it for 5 minutes at RPMs not  
exceeding 2,000, and then drain immediately- do NOT drive the car.   
Watch out for splashes since the hot oil will be very thin.  Change  
the filter (prefill it with oil, if it hangs on your engine), refill  
with a -true- synthetic oil (ie Mobil 1, Amsoil, etc).

NOTE- one risk with this procedure is similar to why people with  
blood clots aren't given big doses of blood thinners; you can have a  
clump break off and clog something up.  I believe this is a risk with  
varnish buildup, not sludge, so I think you'll be fine.

Make sure of course that all of the used items end up getting recycled!

Brett
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