ACK! Re: it's not an urban legend

[Gerard]

All that sounds very much like the warnings you get when switching to
fully synthetic oil from dino-sauce. The high detergent content of the
synthetic oil will loosen up heavy deposits and can open up so-called
"gaskets" where the old critter juice was coked up and blocking exits.

I can attest to that kind of behaviour due to my childish enthusiam to
have synthetic oil in my newly acquired Audi 200 way back in 1997. All I
could find was a wonderful brand called Duckhams. Mobil 1 was unheard of
in the town I worked in. So I took the oil. It had a spec of 0W30. Today
I reckon I should have a can of that on hand when I renew my Mobil 1
synthetic oil. Run some of the 0W30 with the synth oil through the
engine, then replace with new Mobil 1.

Honestly, the 0W30 must have had something strange or super strong in it
'cos it sure cleaned out that engine. Gaskets included.

Shortly after that I had the gasket replaced by a professional dimwit
(not to be mistaken with me. I am a amateur dimwit). It was just
silicone and on the day I took the car away I got a "clunk" from the
motor and the oil pressure dropped. I then had another technician put a
real gasket on. About 18 months later I had the engine stripped only to
find a big hole in the pickup sieve in the sump. Only conclusion was
that something had been sucked through it. Like silicone for example.

Sounds like this ATF method should be kept to engines that are in a very
happy state.

G.