Engine Cleaning The Chemical Way

[JohnJL]

...as opposed to the hard way...that's what I'm lookin for.

So far, I've washed everything in my parts washer with a "bio" degreaser and rinsed everything off well. That seemed to leave a chalky-white residue and on some places hard "crystalline" salts on the parts. These salts are very hard and though a scouring pad will wear it down a bit, it won't take them all the way off.

So, I tried a diluted solution of Hydrochloric acid. I could dee small bubbles coming off the metal, but after rinsing it off, there was no difference in the finish and chalky residue or the crystaline salts.

So then I soaked the parts in "mag wheel cleaner" as recommended by another pelicaner. This, along with some scrubbing, made the metal shiny, but the salts remain and the surface is still chalky in places where I didn't directly scrub it with the 3M scour pad. It will be impossible to get inside all the head passages and case oil passages to get all that out.

There has to be a chemical dip that will dissolve the "salts" and leave the surface clean without scrubbing everywhere. I chickened out and diluted the acid greatly, but I could see bubbled and smell the reaction, and there was absolutely no change in the crystals.

Any other ideas?

thanks
john

[David]

I've never tried any chemical method to remove the oxidation caused by caustic cleaners, I've just polished it off. This is why I don't use cleaners like Simple Green Automotive or Castrol cleaner on aluminum.

[JohnJL]

What are people flushing through their oil passages/spray bars/piston squirters (before Carb/brake Cleaner) to get the nasty stuff out?

[David]

I use carb cleaner, I believe it cleans better than anything else. Just make sure you use the clorinated stuff not the new "safe" carb cleaner.

For the piston squirters, I spray them with carb cleaner on the back side and then hit them with a little compressed air from the back side to blow the carb cleaner through.

[MobileWrks]

Simple green... Thats the best way to do it. No smell or residue left behind. Have fun..

[Dan in Pasadena]

Man, how hardcore are you? You took hydrochloric acid to your Porsche engine and it started bubbling?

Holy Moly man! My advice would be to use a strong citrus degreaser or even good old fashioned tried-and-true Gunk Engine Brite, carefully mask electrical parts. Use a variety of brushes and scotch brite pads along with VERY careful rinsing...and that is it. No substitute for good old fashioned (but CAREFUL) elbow grease.

[wholberg]

When aluminum is treated with basic (caustic) cleaners, the white residue that forms is either aluminum hydroxide or alumina. In either case, the only way to dissolve these residues is using strong acid, but as you found with the hydrochloric acid, raw aluminum is VERY susceptible to acid attack and an strong enough acid to remove the residue quickly would damage the block badly.

You could try dabbing the residue with boiling vinegar. Vinegar is about 5% acetic acid, a much weaker and safer acid than hydrochloric for aluminum. Boiling it should improve its ability to dissolve the residue. If you could drop the entire block into a vat of boiling vinegar for 30 minutes or so, that would probably do it, although it is obviously not feasible. The larger crystals will probably just have to be scrubbed off.

The obvious solution is not to use caustic degreasers on aluminum. Use citra-solve, simple green, or some organic liquid like stoddard solvent.

If you must use caustic cleaners, try flooding the area with inexpensive distilled white vinegar immediately afterwards, followed by copious amounts of water. You can buy it in one gallon bottles for pennies. This MIGHT prevent residue formation, but better to avoid the issue entirely.

[Shaun @ Tru6]

Simple Green, scrub followed by a case of BrakeKleen.