I was wondering what the best way to clean up carbon off of the Pistons and valves is since I have to change 2 head gaskets

I heard abrasive cloths and cleaners aren't so good for the piston heads, then I heard BBQ grill cleaner but I've never done this before so I'm not sure how safe it is

The whole engine isn't being removed, just a head gasket change out and fuel injector cleaning

  • Best left alone, and also depends on how bad the carbon buildup is whether it is worth the risk of getting carbon and chemicals down in the piston rings.
    – Moab
    Commented Jan 4, 2019 at 15:20

2 Answers 2


If you want to clean up the carbon from the top of the pistons, use carburetor cleaner applied to a cloth. Clean shop rags will work, but if not available, paper towels will do the job as well ... it will just take a lot more of them as they will want to wear out faster and leave more fibers behind than a shop rag will. This will clean the carbon without issue and by putting it onto the cloth, it will keep from contaminating the oil with excess fluid which might run down the sides of the piston past the rings.

  • Just tried carburetor cleaner on the head and it does take it off, but takes forever :/ I think I'm going to try dawn dish soap, it cuts through grease pretty good
    – user38183
    Commented Jan 7, 2019 at 4:26

I think that BBQ grill cleaner could be too aggressive for the aluminum/bearing material when it seeps in the block (and stays there until diluted sufficiently by the coming oil changes). Perhaps clean most of the junk with a wooden scraper. Let the rest in and clean it by using good engine oil and performing an italian tuneup (running the car at full load for extended periods).

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