I have a high milage car and when a few times too many in getting the
oil changed.  Live and learn.  Anyway the symptoms are a rattleing
sound only if I try to drive it before warming the car up.  It NEVER
rattles in idle.  Only when excellerating and again only if its not
warmed up.

I had a sludge removal treatment done at the last oil change.  It
helped a little as the rattleing is not loud.  A mechanic friend said
the problem is:

Sludge build-up is causing the "lifters" are sticking when engine is
cold.

He highly recomends the following treatment to fix the problem one and
for all.

1.  Add a quart of automatic transmission fluid to the oil crank case
and let the motor run on idle for 5 minutes.

2. Drain the oil pan.

3. plug pan and add 4 to 5 quarts of automatic transmission fluid and
run engine om idle for 20 to 30 minutes.

4. Drain oil pan of the transmission fluid.

5. replace oil filter and fill oil crankcase with motor oil.

6. Add an engine treatment such as slick 50.

7.  Good to go.  This will thoroughly clean the sludge from the engine.

Is this good advise?  I got a secong opinion from anther mechanic
friend and he said this was good advise.  I've never heard of this
before and guess I want to know if anybody else has heard of this
and/or will this harm my engine.