Dissolving carbon

[ZOOMY]

Any ideas on how to remove "VERY HARD" cabon from piston tops. Bench grinder wire brush doesn't touch it. I tried soaking them in laquer thiner over night. I tried aircraft paint stripper. I tried vinegar. I soaked them in used motor oil.......nothing touches them......................zoomy

[SoCoC10]

When we would do a 3.4L GM intake manifold gasket replacement and EGR de carbonized my guys swear the Oreillys house brand brake cleaner would work best. In your case I think you might have to have the Pistons media blasted.

[IIGW]

ive only ever used a wire brush in a drill and that removes anything ive ever came across..

also, dont forget your good friend Oven Cleaner... stuff will remove everything for nearly .99 cents per can, it's a life saver..

[davepl]

Straight Simple Green reportedly softens carbon up.

To completely dissolve it you're going to need a solvent that can dissolve carbon, and the people who sell that are gunsmiths. They deal with carbon build up all day in the form of burned gunpowder.

Their parts are smaller so I doubt the solvent is cheap by the gallon, but it works. They also have copper cleaners which I thought was pretty fancy (don't think it dissolves copper, but it removes it).

[Grumpy old man]

If it was running, The old trick was to get the engine warmed up and then VERY slowly pour clean cold water down the carb with the engine rpm's at about 1,500 and the cold water would hit the hot carbon on the piston and valve and crystallize it and blow it off . Yeah I know sounds crazy but it works ! I'm not encouraging anyone to do this just an old mechanics trick from back in the days of ....Well..these trucks .

[FirstOwner69]

I had a '65 Impala SS with a 327 in the late 60s. It had a habit of building up carbon deposits in the cylinders. It would break free if I beat the car and knock like mad. I believe this is the current version of what the dealer used. As I recall, they poured it into the cylinders and let it soak for several hours then started it up. Might be worth a try.

Amazon.com: Genuine GM Fluid 1052626 Upper Engine...
Amazon.com: Genuine GM Fluid 88861803 Upper...

[Grumpy old man]

The best and easiest method to remove carbon deposits or built up carbon is to use Marvel mystery oil . it contains refined Stoddard solvents also known as mineral spirits . I've used it to remove carbon on 6 cyl air cooled aircraft engines pistons and valves .Aircraft engines have to be inspected (compression check) every 100 hours and replaced every 2,500 hours if you had a low cylinder it was usually due to carbon on the valves from running 100 low lead fuel .

[CastIron]

Originally Posted by FirstOwner69

I had a '65 Impala SS with a 327 in the late 60s. It had a habit of building up carbon deposits in the cylinders. It would break free if I beat the car and knock like mad. I believe this is the current version of what the dealer used. As I recall, they poured it into the cylinders and let it soak for several hours then started it up. Might be worth a try.

Amazon.com: Genuine GM Fluid 1052626 Upper Engine and Fuel Injector Cleaner - 13 oz. Aerosol: Automotive

Amazon.com: Genuine GM Fluid 88861803 Upper Engine and Fuel Injector Cleaner - 16 oz.: Automotive

I have used GM top engine cleaner many times and it does do a nice job cleaning things up. The second thing you linked is actually fuel injector cleaner that is mixed with fuel and ran directly into the fuel rail. It isn't recommended to put in the fuel tank. Neither product should be used very frequently. If you have the pistons out of the block the top engine cleaner should work great.

[davepl]

A little off topic for our trucks, but now that engines are going direct injection we're going to have to be ramming stuff down the intake path (Seafoam, etc) because putting it in the tank bypasses the valves now!

If doing the water thing, keep in mind that if you somehow ingested enough water to fill even one combustion chamber, just 80cc or whatever, you could hydraulic a cylinder and crack the block. You'd probably have to be pretty aggressive to have a hope of doing that if you -wanted- to, but go slow anyway if you're going to try it.

If -will- try to die on you, so be handy with the throttle. And pour really slow ;-O

[trac209]

Originally Posted by davepl

A little off topic for our trucks, but now that engines are going direct injection we're going to have to be ramming stuff down the intake path (Seafoam, etc) because putting it in the tank bypasses the valves now!

If doing the water thing, keep in mind that if you somehow ingested enough water to fill even one combustion chamber, just 80cc or whatever, you could hydraulic a cylinder and crack the block. You'd probably have to be pretty aggressive to have a hope of doing that if you -wanted- to, but go slow anyway if you're going to try it.

If -will- try to die on you, so be handy with the throttle. And pour really slow ;-O

A spray bottle works well for this trick

[El Dorado Jim]

Originally Posted by trac209

A spray bottle works well for this trick

x2

[RedRoad]

Ive soaked pretty crusty pistons in straight Purple Power

[leddzepp]

Sea foam works great if you slowly pour it down the carb while the truck is running. Shut it down, wait 20 mins and fire it up. Beware that it will look like a forest fire and birds will drop out of the sky