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How to clean an aluminum engine

2006

I'm an amateur car renovator and have an aluminum engine block (Buick) that has internal burnt on oil/coke staining. I need to totally clean the interior of the block by a chemical method. Can you recommend a D-I-Y product that could be painted on to dissolve the staining?
I have been told that an alkaline bath will also do. Is the an Alkaline solution I could manually apply? I do not want to the chemicals to damage to structure.
Thanks,

Brian Bourne
Aircraft engineer - Stansted Airport, London, UK

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2006

There are a couple of products that you could look at using. There are immersion stripping solutions that are widely available, the main constituents that you need to look for are methylene chloride and phenol. With this type of product immersion for around 30 minutes is all that is required. It will remove paint, oil/carbon deposits and most stains. Make sure that you steam cleaner ⇦ this on eBay or Amazon [affil links] it afterwards having first scrubbed all surfaces with a detergent. It is very important to dry out the bores immediately after steam cleaning and then applying CRC or similar lubricant to prevent rusting.

The other product that you could look at if you have some very hard to remove stains would be a very dilute Hydrofluoric acid and water solution. You must clean the block very thoroughly after this treatment and apply a light film of CRC afterwards to prevent further corrosion.

Be careful with either of these processes, the chemicals are not at all good for you.

Good luck

Mark Charles
- Auckland, New Zealand