Thread: Cleaning tops of pistons?

Turn engine so piston is at TDC
Put a smear of grease between the piston and bore
Use a suitable scraper to remove carbon
Clean grease off afterwards - and drop piston to BDC and clean any remaining grease or carbon from top

Important note.

The suitable scraper should not be of steel, this may damage the piston top with nicks and raised points that will give hotspots, and you can diesel your engine, also known as pre-ignition. You know, turn the key off, but the petrol engine keeps trying to run on?

Please, use a hard wooden stick type thing.

During my Navy time, we used strong brown vinegar, to loosen the carbon from injectors etc, prior to cleaning. Probably not a good idea if you don't want to remove the pistons.

Hope this helps

Shorty.

I just had mine off and found that the green scouring pads work well, they dont scratch the pistons. Do the TDC bit and the grease, wet the piston with water,let soak a bit and scrub away .
Something else, do the welch plugs whilst the heads are off, mine looked fine, but had to come off again due to the RH rear leaking . They are tricky, they don't knock in, you have to pull them out.