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Cleaning carbon deposits, recommended cleaners

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techguru

Automotive
May 31, 2003
24
What cleaner makes it easiest and fastest to clean carbon from piston tops and manifolds while i have a motor taken apart. hopefully something that will save me from scrubbing too much. any ideas, or what do you use? What about while a motor is running? I have heard of people using water, but i would think it would take a lot of miles with water injection to clean out a normal amount of deposits. thanks for any info you can provide!
 
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throwing rice down a motor! sounds like a wedding or something. if i saw someone doing that, i beleive it would appear quite comical!
 
When I mentioned Lacquer Thinner, I intended it being used on disassembled engines. Not actually running through them to be burned. I apologize for not clarifying that initially.

Shaun TiedeULTRADYNE Arl,TX(stiede@ev1.net)
 
DrWebb writes:

Lacquer thinner is a chlorinated solvent.
___________________________________________

Are you sure about that?


There are hundreds of different blends of lacquer thinners,
I havent seen one currently mfd. that is chlorinated.(that
doesn't mean there isn't one or more) The EPA doens't like
that idea in the same way they nixed R12(CCl2F2) freon in
favor of R134a. (tetrafluoroethane) The parts dip I
referenced earlier is without a doubt a chlorinated solvent
though. Normally it has a less volatile oily type surface
layer that reduces the amount of vapor that enters the
atmosphere. (as long as it remains in the supplied
covered dip bucket)

Just a theory on the O2 sensor destruction when water
blasting with the engine running. Hard carbon deposits on
the cylinder head and piston tops generally contain sulfur,
zinc, phosphorous and other trace elements found in fuel
and motor oils. They burn if they are rapidly knocked off
the combustion chamber surfaces if the engine is running
with sufficient O2, additional fuel, and an ignition source
present. It wouldn't surprise me that their oxides find
the O2 sensor(s) and the catalytic converter(s) on their
way out the tail pipe! Water (as a gas) is a normal
byproduct of the combustion process. If it was a major
problem at the normal concentrations, I would think we
would hear more about it.

GM and a few other mfgrs. also have some solvent based
injectable decarbonizing treatments(engine running) that
they recommend as a part of their TSB's.

Chumley
 
I'm going from memory here, but I have to agree with Chumley

All the solvents and thinners tins I remember reading, said Acetone, Methyl Ethyl Keytone, MIBK, Toluene, Xylene and/or Liquid Hydrocarbons.

Not a chlorine atom in sight, and for good reason. Chlorinated hydrocarbons are a much greater risk to health than are hydrocarbons or keytones.

Regards
pat
 
i always use diesel to clean the engine parts...i've cleaned up heads and intake manifolds with it and it worked very well
 
At least for a running engine, I always use GM top end engine cleaner. Works like a charm, just make sure you do it far away from anyone who might complain, because the stuff that comes out, if it isn't toxic, sure smells like it.

For disassembled engines I always use either Gasoline or Lacquer thinner ( Lord knows it is not as safe as other things though )
 
Now wait just a second here. I was given to believe that the primary concern when you burn chlorinated combounds was the production of phosgene gas. I've never heard anything that said hydrochloric acid was a byproduct as well. Although admittedly phosgene poses a much greater health risk than does HCL, I would still think that it would at least be worth mentioning it to someone. Can anyone else either confirm or deny this claim?
 
I think you will find that O2 sensors are frequently based on a heated ceramic substrate technology which is very susceptible to thermal shock. The sensor may have a shield around it to provide reasonable protection, but I believe a sudden deluge of water is likely to cause failure.

PJGD
 
I just looked up Phosgene on the BOC Gas site.

The BOC site has some alarming and specific warnings about Phosgene

It is HCl2O, so it certainly could be a by product of the combustion of hydrocarbons and chlorinated hydrocarbons.

It is extreamly toxic, but unstable in contact with moisture, where it breaks down to hydrochloric acid.

I GUESS that by the time it comes out the exhaust in contact with large amounts of water vapour, it is mainly but not completely converted to HCl.

Either way, not nice for people and parts.

Bottom lone. DO NOT PUT CHLORINATED HYDROCARBONS INTO A RUNNING MOTOR, and be very carefull about useing them to wash parts



Regards
pat
 
patdaly writes:

"At least for a running engine, I always use GM top end
engine cleaner. Works like a charm, just make sure you do
it far away from anyone who might complain, because the
stuff that comes out, if it isn't toxic, sure smells like
it."

Still laughing! (I knew that!) Smells like it, and looks
like it! Wynn's V.I.C., same thing! But, . . . . it
works! Post dusk treatment advised.

Chumley
 
Re patdaley writes
Opposite problem with Phosgene.
Colourless and odourless. First sign is some irritation of the mucouse membranes. By then you already have a fatal dose.
It kills you before you even know it's there

Regards
pat
 
Hi Pat. I'll have to look that Phosgene gas info up.
Somehow, somewhere, I knew burning chlorinated compounds
locally isn't the thing to do. I guess I haven't been
(seriously) exposed to it, at least as of yet. I loved
chemistry in college until one of my favorite professors
one day told me, "You do know, Chumley, that as of today,
the average life of a lab chemist is 58 years?"

Thanks to techguru for asking the initial question for
this thread.

Chumley
 
I have recently stumbled across a product that has been a godsend. Its schaffer's oil fuel additive #131. Its a fuel additive that can also be used to clean combustion chambers. I have a 1978 slant six that pinged like crazy and would only not ping while using premium 93 octane. I ran it on regular but the timing had to be pulled back 7-10 degrees depending on the temperature.

I found bobistheoilguy forum and found out about the additive. I bought a gallon. It had instructions on the bottle on how to use it to clean the cylinders. On fast idle, I slowly poured 16 ounces down the carb.

The results were stunning. I was able to go back up to factory timing settings, run the carb leaner, and it does not ping under any condition with 87 octane regular. Also runs like it should and it gets 20mpg now instead of 14-16.

I like it due to the fact that it is made for an engine and does not create other problems that using atf, water, or cleaners mentioned earlier in this thread do. It can even be used in the oil to help clean the engine.

Dan
 
MOBIL1 synthetic used to clean a sludged engine works well in the oil pan if the engine gets 180*+.

Shaun TiedeULTRADYNE Arl,TX(stiede@ev1.net)
 
My coworker just tried some Berryman's engine cleaner. Now he's rebuilding it....
 
this ended up being a super good post, thanks for all the input guys.
 
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