Synthetic oil caused lifters to go bad?

[Luis Marques <marques@ti.com>]

> Is it advisable to use synthetic oil in this Audi?  I have a '90 80q
> that I switched over to Mobil 1 at 60K miles and it caused my lifters
> to go bad.  After replacing all of the lifters and switching back to
> "real" oil and changing at 3K intervals, I haven't had another problem.

And I ask: did the lifters really go bad, or were they just noisy due to
all that sludge suspended in the oil?

Dave Weiss wrote:
> Might be coincidence, but my 200Q's lifters started clacking 4-5k mi
> after switching from Pennzoil to Mobil 1.  This time, I had the sludge
> cleaned out (Bilstein) and did the lister-recommended short-change
> routine.  Insurance against changing 32 lifters.

I don't think the lifters would go bad simply because you don't do the
engine clean-out thing.  I believe that it's just a matter of removing
all the sludge and gunk left behind by the dino oil.  A special engine
cleaning treatment may remove must of the stuff quickly, whereas it
would probably take 4 oil changes with the sinthetic oil to achieve the
same results.  As the synthetic oil disolves the gunk from the engine,
at some point, it will become saturated with this sludge and all the
lifters will start making a rattle.  But after an oil change, they
should be quiet again, untill the synthetic oil removes some more sludge
from the engine, at which point it would be time for a new oil change.

I know that the manufacturers of these synthetic motor oils claim that
you can use extended drain intervals with their products, but I just
change the oil when the lifters get too noisy or twice a year, whichever
comes first.  That about every 5-7K mi. BTW.

Luis Marques
'87 4kcsq, Mobil 1 + Mahle filter