BIG ALERT HERE!! - BBQ degreaser is definitely not the the stuff to use around your engine!! It is based, like oven cleaner, on Caustic Soda (Sodium hydroxide - NaOH). Sodium hydroxide just adores aluminium and related alloys and eats them like there is no tomorrow.
BTW, your little exercise also evolved hydrogen gas, not that you would have noticed. Believe me, I've generated hydrogen for years by that method. The reaction is 2Al(s)+ 2NaOH(aq)+ 6H2O (l)---->2NaAl(OH)4(aq)+3 H2 (g)
Just because something says "degreaser" on the can, do not assume that all degreasers achieve their effect the same way. BBQ cleaner uses NoAH in order to saponify all the fats that you didn't eat and left on the BBQ - the saponification turns the non-water-soluble fat to soap which you can then wash off. Engine degreaser relies on the "common solvent" principle, a washable mineral oil, sometimes with a protective oil film residue to prevent subsequent rusting of the degreased steel or iron surfaces, that dissolves your years of caked on engine gunk. Engine degreaser is the stuff to use on mineral oil-based messes, or if it is water based, then use water.
The best remedy for your mistake is to warm the engine slightly and then flood any likely affected areas of alloy (your entire timing cover area by the look of things, and possibly RH cam cover section, at least) with standard household vinegar and let it stand for 10-15 minutes then wash and wash and wash and wash with plain, fresh, clean warm water and let it dry.
There are many other mild acids to use that will achieve the same alkali neutralizing effect, but I'm suggesting one that a) won't mess up your engine and b) you can get off the shelf at the shop. Use clear white vinegar, not brown, although it won't matter much.
Do not use hydrochloric, phosphoric or battery acid! And do not assume that due to the passage of time that it will be "all OK by now". It might be, as I don't know how long it has been sitting there, but the NaOH will stay there in nooks and crannies and eat away at your alloys until it is exhausted by the end of the reaction above and all turned to sodium aluminium hydroxide. Get rid of it!
Last edited by Doug_MPS6; 06-07-2012 at 11:04 PM.
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