Bill Noble wrote:
so the metal is my car's engine - a horizontally opposed 6, that has
some air passages (supplementary air injection) that are clogged by
carbon, which causes the check engine light to come on - this is an
emissions control only issue, but it's annoying. There are two known
procedures for fixing, one involves removing the heads and cleaning them
- this is VERY expensive, and not all that sensible for a properly
running engine. The other procedure involves flushing some kind of
magic compound through the passages using air pressure and a lot of
prayers. I've used this procedure with success, but each time the
interval between failure gets shorter because of course some of the
build up remains - I've made (there's metal content) special adapters so
I can put 160 PSI air where the low pressure blower air normally goes to
help pop out the blockage - this "kind of" works - but what would really
help is some magic goop that would attack the carbon, not eat the
aluminum heads, and not cause engine damage if some managed to work its
way inside the cylinders

So, any ideas? (I've used spray carb cleaner and fuel injector
cleaner, the former works a lot better than the latter) - I've tried
wire probes (access is quite limited), a micro rotor-rooter type thing I
made from a speedo cable, and other mechanical means - none worked worth
a darn.

so, there is no politics, and it has a modest relationship to real metal
working, and someone may have an idea to help....


I would add to all the suggestions for Sea foam etc: If you car has a
catalytic converter, whatever you pour through the engine exits through
the converter, and can clog it.

One thing I would probably do if it were mine, is add a water injection
system at the intake. Nothing like steam for removing deposits, and it
will not hurt the motor, and would probably help it. Of course water
injection is added to reduce detonation and thereby improve power. A
side benefit is it cleans combustion chambers and passages like nothing
else.

Holley used to make a nice kit. I still happen to have one, much to my
recent surprise. There are probably newer and better ones out there by now.