After detecting white colored sludge in the overflow reservoir,
I cleaned and flushed the radiator coolant.
Now, in stop-go traffic, the car still overheats occasionally.
I am speculating that the radiator core is still congested with the
white sludge, which mostly likely formed due to using the wrong
The car also failed the California Gross Polluter smog test.
(The NO (PPM) figures where slightly out of range to the upside.)
I have read this could be caused by a too high burn temperature in the
combustion chamber. The sparkplugs tend to confirm this by displaying
a white color, and likely caused by the overheating.
I think I will remove the radiator and do a reverse flush with a
garden hose. Most likely this will not work and there may be no other
way to flush the radiator with chemicals.
This experience confirms that the audi must have the right antifreeze
solution to minimize this kind of mess.
Anybody out there with a similar experience?