ACDelcoGM Original Equipment 10-3015 Engine Cylinder/Combustion Chamber Cleaner - 32 oz

I used this to soak the pistons in my 275k mile 2007 prius overnight and I went from burning 1 quart of oil every 700 miles down to 1 quart over the whole 5000 mile oil change interval!I removed the spark plugs, added about 1/4 cup to each piston, moved it up and down a few times and then let it sit overnight. In the morning I vacuumed the remaining liquid out with a mitivac and a whole bunch of junk came out. The car smoked a bit upon startup, I did some hard driving to really ensure it got worked in and had great success.

Did a compression test before adding this to the cylinders and letting it sit overnight. Then blew it out, burned any remaining off by letting car run for 15 minutes, than did an after compression test. The before test had cylinders between 125-140, after, all 6 cylinders were right around 170.

I've been trying to clean these pistons with brake cleaner, carb cleaner, sea foam, and several other cleaners nothing really worked at all then I took a chance on this and wow did it work great. I poured a small amount onto a paper towel and coated the piston as I did this I could see it start to run off right away gave it a few seconds and bam it wiped off like a nonstick skillet with just a paper towel crazy. I had 2 pistons in the back that were really bad and I had to let it sit on them for a minute or two but bam came clean if you need to clean carbon build up and stains on pistons or engine parts this is worth every penny turned a 2-3 hr cleaning job into a 15 minute job. Don't hesitate just buy it.

Used this cleaner for a top end soak overnight to clean carbon off piston rings of a 04 accord that was consuming oil. It worked perfectly after using the eng starter to pump most of it out no more oil consumption. Note your engine will smoke considerably until all of the remaining cleaner is burned up. No check engine light was set off. Highly recommend as an option, also check pvc system to make sure it’s functional. Use at your own risk it worked for me may not for you.

the old x66 top engine cleaner is discontiunued i used it in past at felix chervrolet when i was a tech thier 30 years ago .my 2000 honda accord was burning oil 2 Quarts at 300 miles major oil consumption i used this new fourmla and soaked overnight plus again for another 3 hrs did a oil change with valvoline restore and protect 5w30 so far havent lost any oil at ilttle over 300 miles

Heard about this in forums, as being superior to other top engine treatments. Used it as an overnight top-piston soak, plus as aspirated via vacuum into the intake manifold with engine running. Although initially the post-treatment cylinder compression read 4% lower at first, the engine ran smoother and more quietly, peppier, and the engine monitor readout of mileage went up by 10%. Thus, good signs of effective carbon cleanout. In time, I'll reevaluate the compression and mileage results. Although this is pricier than similar products, it appears to work quite effectively. I'll carry on to keep carbon minimized, such as with use of Top Tier gasolines and synthetic oil.

Takes it all off…. Good degreaser for unpainted surfaces

Car using oil badly ( 50 miles to the quart!) .suspected stuck oil rings. soaked the pistons by pouring it down the spark plug holes and letting it set . Bore scope inspections showed carbon mostly gone . Had to eventually remove the pistons as cylinder walls were glazed too . BUT all piston rings in their grooves were free of carbon and moved easily in the piston lands- upon removal of them from the engine .B-12 chemtool works well also in this matter , a lot cheaper too .