From: John De Armond
Newsgroups: rec.autos.tech
Subject: Re: How dumb would this be?
Date: Fri, 02 Mar 2001 17:05:14 -0500

"Clifton T. Sharp Jr." wrote:

> I'm wondering how stupid it would be to run some engine flush through
> the engine.

Well, let's reason it through.

With your current situation, you have a little tap that may or may
not mean anything in a car that old.  There's an indeterminate
amount of gunk on various internal surfaces (NOT moving parts like
bearings!) that is fixed in place.  There is new oil in the engine.

Now consider what happens when you dump in a can of "engine flush"
which is usually a mix of solvents and detergents.  Some fraction of
that previously fixed gunk (which wasn't really harming anything)
will be loosened and suspended in the oil.  It will be picked up by
the oil pump which will receive extra wear from the abrasiveness.
It will pumped through the oil galleys to the oil filter.  Some, but
not all, will be trapped in the filter.  The remainder will be
transported throughout the oiling system to the bearings, pistons,
rings, valves, cam, etc where it will act like grinding compound.
Get the picture?  Pretty dumb idea.

There's a little rule of thumb that goes something like this:  There
ain't no such thing as a "mechanic in a can".  If it's intended to
be dumped in the oil filler and it ain't oil, at best it can do only
one thing - relieve you of a few dollars.  At worst, welll.....

John